Abstract:
A data transmission system for minimizing the number of errors during Tx/Rx times of mobile service data under mobile environments, and a data processing method for the same are disclosed. The system additionally codes the mobile service data, and transmits the resultant coded mobile service data. As a result, the mobile service data has a strong resistance to noise and channel variation, and can quickly cope with the rapid channel variation.

Description:
[0001]    This application claims the benefit of the Korean Patent Application No. 10-2007-0036701, filed on Apr. 14, 2007, which is hereby incorporated by reference as if fully set forth herein. Also, this application claims the benefit of U.S. Provisional Application No. 60/912,119, filed on Apr. 16, 2007, which is hereby incorporated by reference. This application also claims the benefit of U.S. Provisional Application No. 60/947,984, filed on Jul. 4, 2007, which is hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a method and apparatus for transmitting/receiving mobile service data and controlling the received mobile service data. 
         [0004]    2. Discussion of the Related Art 
         [0005]    The Vestigial Sideband (VSB) transmission mode, which is adopted as the standard for digital broadcasting in North America and the Republic of Korea, is a system using a single carrier method. Therefore, the receiving performance of the receiving system may be deteriorated in a poor channel environment. Particularly, since resistance to changes in channels and noise is more highly required when using portable and/or mobile broadcast receivers, the receiving performance may be even more deteriorated when transmitting mobile service data by the VSB transmission mode. 
       SUMMARY OF THE INVENTION 
       [0006]    Accordingly, the present invention is directed to an apparatus for receiving mobile service data and a method for controlling the same that substantially obviates one or more problems due to limitations and disadvantages of the related art. 
         [0007]    An object of the present invention is to provide a an apparatus for receiving mobile service data and a method for controlling the same which has very strong resistance to noise and channel variation under a mobile environment. 
         [0008]    Another object of the present invention is to provide an apparatus for receiving mobile service data and a method for controlling the same which additionally encodes mobile service data and transmits the encoded mobile service data to a mobile reception system, thereby improving a reception (Rx) performance of the mobile reception system. 
         [0009]    Another object of the present invention is to provide an apparatus for receiving mobile service data and a method for controlling the same which inserts known data recognized by an agreement between a transmission end and a reception end into a predetermined area of a data region, and transmits electronic program information, thereby improving a reception (Rx) performance of the mobile reception system. 
         [0010]    Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
         [0011]    To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a method for storing mobile service data comprises: receiving coded mobile service data; demodulating received mobile service data; controlling a storing the mobile service data; and controlling reproduction or playback of the stored mobile service data. 
         [0012]    In another aspect of the present invention, there is provided an apparatus for receiving mobile service data comprising: a signal receiver for receiving coded mobile service data; a demodulator for demodulating received mobile service data; and a controller for storing the mobile service data, and controlling reproduction or playback of the stored mobile service data. 
         [0013]    It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings: 
           [0015]      FIG. 1  illustrates a block diagram showing a general structure of a digital broadcasting system according to an embodiment of the present invention; 
           [0016]      FIG. 2  illustrates a block diagram showing an example of a service multiplexer of  FIG. 1 ; 
           [0017]      FIG. 3  illustrates a block diagram showing an example of a transmitter of  FIG. 1 ; 
           [0018]      FIG. 4  illustrates a block diagram showing an example of a pre-processor of  FIG. 3 ; 
           [0019]      FIG. 5(   a ) to  FIG. 5(   e ) illustrate error correction encoding and error detection encoding processed according to an embodiment of the present invention; 
           [0020]      FIG. 6A  and  FIG. 6B  illustrate data configuration before and after a data deinterleaver in a digital broadcast transmitting system according to the present invention; 
           [0021]      FIG. 7  illustrates a process of dividing a RS frame for configuring a data group according to the present invention; 
           [0022]      FIG. 8  illustrates exemplary operations of a packet multiplexer for transmitting the data group according to the present invention; 
           [0023]      FIG. 9  illustrates a block diagram showing a structure of a block processor according to the present invention; 
           [0024]      FIG. 10  illustrates a detailed block diagram of a symbol encoder shown in  FIG. 9 ; 
           [0025]      FIG. 11(   a ) to  FIG. 11(   c ) illustrate a variable length interleaving process of a symbol interleaver shown in  FIG. 9 ; 
           [0026]      FIG. 12A  and  FIG. 12B  illustrate block diagrams showing structures of a block processor according to another embodiment of the present invention; 
           [0027]      FIG. 13(   a ) to  FIG. 13(   c ) illustrate block encoding and trellis encoding processes according to the present invention; 
           [0028]      FIG. 14  illustrates a block diagram showing a trellis encoding module according to the present invention; 
           [0029]      FIG. 15A  and  FIG. 15B  a block processor and a trellis encoding module connected to one another according to the present invention; 
           [0030]      FIG. 16  illustrates a block processor according to another embodiment of the present invention; 
           [0031]      FIG. 17  illustrates a block processor according to yet another embodiment of the present invention; 
           [0032]      FIG. 18  illustrates an example of a group formatter inserting and transmitting a transmission parameter; 
           [0033]      FIG. 19  illustrates an example of a block processor inserting and transmitting a transmission parameter; 
           [0034]      FIG. 20  illustrates an example of a packet formatter inserting and transmitting a transmission parameter; 
           [0035]      FIG. 21  illustrates an example for inserting and transmitting the transmission parameter in a field synchronization segment area; 
           [0036]      FIG. 22  illustrates a block diagram showing a structure of a digital broadcast receiving system according to the present invention; 
           [0037]      FIG. 23  is a block diagram illustrating a reception system according to the present invention; 
           [0038]      FIG. 24  is a conceptual diagram illustrating an exemplary error correction decoding process according to the present invention; 
           [0039]      FIG. 25  is a flow chart illustrating an automatic channel setup method according to one embodiment of the present invention; 
           [0040]      FIG. 26  is a flow chart illustrating an automatic channel setup method according to another embodiment of the present invention; 
           [0041]      FIG. 27  is a flow chart illustrating an automatic channel setup method according to another embodiment of the present invention; 
           [0042]      FIG. 28  exemplarily shows the list of channels established by the automatic channel setup method according to the present invention; 
           [0043]      FIG. 29  is a conceptual diagram illustrating a manual channel setup method according to the present invention; 
           [0044]      FIG. 30  is a block diagram illustrating an apparatus for multiplexing a broadcast signal received from several input sources using a mobile broadcast receiver according to the present invention; 
           [0045]      FIG. 31A  and  FIG. 31B  show user-selection screen images according to the integrated source program information; 
           [0046]      FIG. 32A  and  FIG. 32B  show examples for adjusting an image setup value according to the present invention; 
           [0047]      FIG. 33A  and  FIG. 33B  show methods for adjusting a color temperature according to the present invention; 
           [0048]      FIG. 34  is a conceptual diagram illustrating a method for initializing an image setup value or a color temperature according to the present invention; 
           [0049]      FIG. 35  shows an example for establishing an audio setup method according to the present invention; 
           [0050]      FIG. 36A  and  FIG. 36B  show another example of an audio setup method according to the present invention; 
           [0051]      FIG. 37  is a flow chart illustrating an automatic channel setup method according to another embodiment of the present invention; 
           [0052]      FIG. 38  is a flow chart illustrating a manual channel setup method according to another embodiment of the present invention; 
           [0053]      FIG. 39  shows an example of another time information setup method according to the present invention; 
           [0054]      FIG. 40A  and  FIG. 40B  show a method for establishing an aspect ratio according to the present invention; 
           [0055]      FIG. 41A  and  FIG. 41B  show an example for establishing caption-associated information according to the present invention; 
           [0056]      FIG. 42A  and  FIG. 42B  show another example for establishing caption-associated information according to the present invention; 
           [0057]      FIG. 43A  and  FIG. 43B  show an OSD setup method according to the present invention; 
           [0058]      FIG. 44A  is a conceptual diagram illustrating a PIP control method according to the present invention; 
           [0059]      FIG. 44B  is a conceptual diagram illustrating another PIP control method according to the present invention; and 
           [0060]      FIG. 45A  and  FIG. 45B  show a method for controlling the menu display according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0061]    Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. In addition, although the terms used in the present invention are selected from generally known and used terms, some of the terms mentioned in the description of the present invention have been selected by the applicant at his or her discretion, the detailed meanings of which are described in relevant parts of the description herein. Furthermore, it is required that the present invention is understood, not simply by the actual terms used but by the meaning of each term lying within. 
         [0062]    Among the terms used in the description of the present invention, main service data correspond to data that can be received by a fixed receiving system and may include audio/video (A/V) data. More specifically, the main service data may include A/V data of high definition (HD) or standard definition (SD) levels and may also include diverse data types required for data broadcasting. Also, the known data correspond to data pre-known in accordance with a pre-arranged agreement between the receiving system and the transmitting system. Additionally, in the present invention, mobile service data may include at least one of mobile service data, pedestrian service data, and handheld service data, and are collectively referred to as mobile service data for simplicity. Herein, the mobile service data not only correspond to mobile/pedestrian/handheld service data (M/P/H service data) but may also include any type of service data with mobile or portable characteristics. Therefore, the mobile service data according to the present invention are not limited only to the M/P/H service data. 
         [0063]    The above-described mobile service data may correspond to data having information, such as program execution files, stock information, and so on, and may also correspond to A/V data. Most particularly, the mobile service data may correspond to A/V data having lower resolution and lower data rate as compared to the main service data. For example, if an A/V codec that is used for a conventional main service corresponds to a MPEG-2 codec, a MPEG-4 advanced video coding (AVC) or scalable video coding (SVC) having better image compression efficiency may be used as the A/V codec for the mobile service. Furthermore, any type of data may be transmitted as the mobile service data. For example, transport protocol expert group (TPEG) data for broadcasting real-time transportation information may be serviced as the main service data. 
         [0064]    Also, a data service using the mobile service data may include weather forecast services, traffic information services, stock information services, viewer participation quiz programs, real-time polls &amp; surveys, interactive education broadcast programs, gaming services, services providing information on synopsis, character, background music, and filming sites of soap operas or series, services providing information on past match scores and player profiles and achievements, and services providing information on product information and programs classified by service, medium, time, and theme enabling purchase orders to be processed. Herein, the present invention is not limited only to the services mentioned above. 
         [0065]    Electronic program information is information of the mobile service data. In this case, the electronic program information may be program information associated with a channel and time of A/V data contained in the mobile service data, or may also be channel- and time-information associated with either data broadcasting or software updating. However, it should be noted that the above-mentioned examples are disclosed for only illustrative purposes. Needless to say, the above-mentioned electronic program information of the present invention includes all information including the above-mentioned mobile service data description. 
         [0066]    The electronic program information contained in the PSI/PSIP data is transmitted to a destination. If there is a specific table equipped with program information in the PSIP/PSI table, a transmitter may include electronic program information in all kinds of tables, and transmit the resultant table including the electronic program information. 
         [0067]    A receiver may extract program information from all kinds of tables, and provide a user with the program information. In an embodiment of the present invention, the receiver extracts the program information from an Event Information Table (EIT) or a Virtual Channel Table (VCT), and provide the user with the extracted program information. 
         [0068]    If an unexpected error occurs while the transmitter transmits electronic program information to the receiver, the receiver may not transmit the program information to the user, or may transmit wrong information to the user. Therefore, there is needed a system capable of transmitting the electronic program information from the transmitter to the receiver under a mobile reception environment. 
         [0069]    A transmission system according to the present invention has no influence on a conventional reception system while the conventional reception system receives main service data. Namely, the transmission system is backward compatible with the reception system. And, the transmission system multiplexes main service data and mobile service data in the same physical channel, and transmits the multiplexed data. 
         [0070]    The transmission system according to the present invention additionally encodes mobile service data and electronic program information, inserts known data pre-recognized by an agreement between the transmission/reception ends into the encoded result, and transmits the inserted result. 
         [0071]    In the case of using the above-mentioned transmission system, the reception system can receive mobile service data while in motion, and can stably receive the mobile service data irrespective of a distortion or noise of a channel. 
       General Description of a Transmitting System 
       [0072]      FIG. 1  illustrates a block diagram showing a general structure of a transmitting system according to an embodiment of the present invention. Herein, the transmitting includes a service multiplexer  100  and a transmitter  200 . Herein, the service multiplexer  100  is located in the studio of each broadcast station, and the transmitter  200  is located in a site placed at a predetermined distance from the studio. The transmitter  200  may be located in a plurality of different locations. Also, for example, the plurality of transmitters may share the same frequency. And, in this case, the plurality of transmitters receives the same signal. Accordingly, in the receiving system, a channel equalizer may compensate signal distortion, which is caused by a reflected wave, so as to recover the original signal. In another example, the plurality of transmitters may have different frequencies with respect to the same channel. 
         [0073]    A variety of methods may be used for data communication each of the transmitters, which are located in remote positions, and the service multiplexer. For example, an interface standard such as a synchronous serial interface for transport of MPEG-2 data (SMPTE-310M). In the SMPTE-310M interface standard, a constant data rate is decided as an output data rate of the service multiplexer. For example, in case of the 8VSB mode, the output data rate is 19.39 Mbps, and, in case of the 16VSB mode, the output data rate is 38.78 Mbps. Furthermore, in the conventional 8VSB mode transmitting system, a transport stream (TS) packet having a data rate of approximately 19.39 Mbps may be transmitted through a single physical channel. Also, in the transmitting system according to the present invention provided with backward compatibility with the conventional transmitting system, additional encoding is performed on the mobile service data. Thereafter, the additionally encoded mobile service data are multiplexed with the main service data to a TS packet form, which is then transmitted. At this point, the data rate of the multiplexed TS packet is approximately 19.39 Mbps. 
         [0074]    At this point, the service multiplexer  100  receives at least one type of mobile service data and program specific information (PSI)/program and system information protocol (PSIP) table data for each mobile service and encapsulates the received data to each transport stream (TS) packet. Also, the service multiplexer  100  receives at least one type of main service data and PSI/PSIP table data for each main service so as to encapsulate the received data to a TS packet. Subsequently, the TS packets are multiplexed according to a predetermined multiplexing rule and outputs the multiplexed packets to the transmitter  200 . 
       Service Multiplexer 
       [0075]      FIG. 2  illustrates a block diagram showing an example of the service multiplexer. The service multiplexer includes a controller  110  for controlling the overall operations of the service multiplexer, a PSI/PSIP generator  120  for the main service, a PSI/PSIP generator  130  for the mobile service, a null packet generator  140 , a mobile service multiplexer  150 , and a transport multiplexer  160 . The transport multiplexer  160  may include a main service multiplexer  161  and a transport stream (TS) packet multiplexer  162 . Referring to  FIG. 2 , at least one type of compression encoded main service data and the PSI/PSIP table data generated from the PSI/PSIP generator  120  for the main service are inputted to the main service multiplexer  161  of the transport multiplexer  160 . The main service multiplexer  161  encapsulates each of the inputted main service data and PSI/PSIP table data to MPEG-2 TS packet forms. Then, the MPEG-2 TS packets are multiplexed and outputted to the TS packet multiplexer  162 . Herein, the data packet being outputted from the main service multiplexer  161  will be referred to as a main service data packet for simplicity. 
         [0076]    Thereafter, at least one type of the compression encoded mobile service data and the PSI/PSIP table data generated from the PSI/PSIP generator  130  for the mobile service are inputted to the mobile service multiplexer  150 . The mobile service multiplexer  150  encapsulates each of the inputted mobile service data and PSI/PSIP table data to MPEG-2 TS packet forms. Then, the MPEG-2 TS packets are multiplexed and outputted to the TS packet multiplexer  162 . Herein, the data packet being outputted from the mobile service multiplexer  150  will be referred to as a mobile service data packet for simplicity. At this point, the transmitter  200  requires identification information in order to identify and process the main service data packet and the mobile service data packet. Herein, the identification information may use values pre-decided in accordance with an agreement between the transmitting system and the receiving system, or may be configured of a separate set of data, or may modify predetermined location value with in the corresponding data packet. As an example of the present invention, a different packet identifier (PID) may be assigned to identify each of the main service data packet and the mobile service data packet. 
         [0077]    In another example, by modifying a synchronization data byte within a header of the mobile service data, the service data packet may be identified by using the synchronization data byte value of the corresponding service data packet. For example, the synchronization byte of the main service data packet directly outputs the value decided by the ISO/IEC13818-1 standard (i.e., 0x47) without any modification. The synchronization byte of the mobile service data packet modifies and outputs the value, thereby identifying the main service data packet and the mobile service data packet. Conversely, the synchronization byte of the main service data packet is modified and outputted, whereas the synchronization byte of the mobile service data packet is directly outputted without being modified, thereby enabling the main service data packet and the mobile service data packet to be identified. 
         [0078]    A plurality of methods may be applied in the method of modifying the synchronization byte. For example, each bit of the synchronization byte may be inversed, or only a portion of the synchronization byte may be inversed. As described above, any type of identification information may be used to identify the main service data packet and the mobile service data packet. Therefore, the scope of the present invention is not limited only to the example set forth in the description of the present invention. 
         [0079]    Meanwhile, a transport multiplexer used in the conventional digital broadcasting system may be used as the transport multiplexer  160  according to the present invention. More specifically, in order to multiplex the mobile service data and the main service data and to transmit the multiplexed data, the data rate of the main service is limited to a data rate of (19.39-K) Mbps. Then, K Mbps, which corresponds to the remaining data rate, is assigned as the data rate of the mobile service. Thus, the transport multiplexer which is already being used may be used as it is without any modification. Herein, the transport multiplexer  160  multiplexes the main service data packet being outputted from the main service multiplexer  161  and the mobile service data packet being outputted from the mobile service multiplexer  150 . Thereafter, the transport multiplexer  160  transmits the multiplexed data packets to the transmitter  200 . 
         [0080]    However, in some cases, the output data rate of the mobile service multiplexer  150  may not be equal to K Mbps. In this case, the mobile service multiplexer  150  multiplexes and outputs null data packets generated from the null packet generator  140  so that the output data rate can reach K Mbps. More specifically, in order to match the output data rate of the mobile service multiplexer  150  to a constant data rate, the null packet generator  140  generates null data packets, which are then outputted to the mobile service multiplexer  150 . For example, when the service multiplexer  100  assigns K Mbps of the 19.39 Mbps to the mobile service data, and when the remaining (19.39-K) Mbps is, therefore, assigned to the main service data, the data rate of the mobile service data that are multiplexed by the service multiplexer  100  actually becomes lower than K Mbps. This is because, in case of the mobile service data, the pre-processor of the transmitting system performs additional encoding, thereby increasing the amount of data. Eventually, the data rate of the mobile service data, which may be transmitted from the service multiplexer  100 , becomes smaller than K Mbps. 
         [0081]    For example, since the pre-processor of the transmitter performs an encoding process on the mobile service data at a coding rate of at least ½, the amount of the data outputted from the pre-processor is increased to more than twice the amount of the data initially inputted to the pre-processor. Therefore, the sum of the data rate of the main service data and the data rate of the mobile service data, both being multiplexed by the service multiplexer  100 , becomes either equal to or smaller than 19.39 Mbps. Therefore, in order to match the data rate of the data that are finally outputted from the service multiplexer  100  to a constant data rate (e.g., 19.39 Mbps), an amount of null data packets corresponding to the amount of lacking data rate is generated from the null packet generator  140  and outputted to the mobile service multiplexer  150 . 
         [0082]    Accordingly, the mobile service multiplexer  150  encapsulates each of the mobile service data and the PSI/PSIP table data that are being inputted to a MPEG-2 TS packet form. Then, the above-described TS packets are multiplexed with the null data packets and, then, outputted to the TS packet multiplexer  162 . Thereafter, the TS packet multiplexer  162  multiplexes the main service data packet being outputted from the main service multiplexer  161  and the mobile service data packet being outputted from the mobile service multiplexer  150  and transmits the multiplexed data packets to the transmitter  200  at a data rate of 19.39 Mbps. 
         [0083]    According to an embodiment of the present invention, the mobile service multiplexer  150  receives the null data packets. However, this is merely exemplary and does not limit the scope of the present invention. In other words, according to another embodiment of the present invention, the TS packet multiplexer  162  may receive the null data packets, so as to match the data rate of the finally outputted data to a constant data rate. Herein, the output path and multiplexing rule of the null data packet is controlled by the controller  110 . The controller  110  controls the multiplexing processed performed by the mobile service multiplexer  150 , the main service multiplexer  161  of the transport multiplexer  160 , and the TS packet multiplexer  162 , and also controls the null data packet generation of the null packet generator  140 . At this point, the transmitter  200  discards the null data packets transmitted from the service multiplexer  100  instead of transmitting the null data packets. 
         [0084]    Further, in order to allow the transmitter  200  to discard the null data packets transmitted from the service multiplexer  100  instead of transmitting them, identification information for identifying the null data packet is required. Herein, the identification information may use values pre-decided in accordance with an agreement between the transmitting system and the receiving system. For example, the value of the synchronization byte within the header of the null data packet may be modified so as to be used as the identification information. Alternatively, a transport_error_indicator flag may also be used as the identification information. 
         [0085]    In the description of the present invention, an example of using the transport_error_indicator flag as the identification information will be given to describe an embodiment of the present invention. In this case, the transport_error_indicator flag of the null data packet is set to ‘1’, and the transport_error_indicator flag of the remaining data packets are reset to ‘0’, so as to identify the null data packet. More specifically, when the null packet generator  140  generates the null data packets, if the transport_error_indicator flag from the header field of the null data packet is set to ‘1’ and then transmitted, the null data packet may be identified and, therefore, be discarded. In the present invention, any type of identification information for identifying the null data packets may be used. Therefore, the scope of the present invention is not limited only to the examples set forth in the description of the present invention. 
         [0086]    According to another embodiment of the present invention, a transmission parameter may be included in at least a portion of the null data packet, or at least one table or an operations and maintenance (OM) packet (or OMP) of the PSI/PSIP table for the mobile service. In this case, the transmitter  200  extracts the transmission parameter and outputs the extracted transmission parameter to the corresponding block and also transmits the extracted parameter to the receiving system if required. More specifically, a packet referred to as an OMP is defined for the purpose of operating and managing the transmitting system. For example, the OMP is configured in accordance with the MPEG-2 TS packet format, and the corresponding PID is given the value of 0x1FFA. The OMP is configured of a 4-byte header and a 184-byte payload. Herein, among the 184 bytes, the first byte corresponds to an OM_type field, which indicates the type of the OM packet. 
         [0087]    In the present invention, the transmission parameter may be transmitted in the form of an OMP. And, in this case, among the values of the reserved fields within the OM_type field, a pre-arranged value is used, thereby indicating that the transmission parameter is being transmitted to the transmitter  200  in the form of an OMP. More specifically, the transmitter  200  may find (or identify) the OMP by referring to the PID. Also, by parsing the OM_type field within the OMP, the transmitter  200  can verify whether a transmission parameter is included after the OM_type field of the corresponding packet. The transmission parameter corresponds to supplemental data required for processing mobile service data from the transmitting system and the receiving system. 
         [0088]    Herein, the transmission parameter may include data group information, region information within the data group, RS frame information, super frame information, burst information, turbo code information, and RS code information. The burst information may include burst size information, burst period information, and time information to next burst. The burst period signifies the period at which the burst transmitting the same mobile service is repeated. The data group includes a plurality of mobile service data packets, and a plurality of such data groups is gathered (or grouped) to form a burst. A burst section signifies the beginning of a current burst to the beginning of a next burst. Herein, the burst section is classified as a section that includes the data group (also referred to as a burst-on section), and a section that does not include the data group (also referred to as a burst-off section). A burst-on section is configured of a plurality of fields, wherein one field includes one data group. 
         [0089]    The transmission parameter may also include information on how signals of a symbol domain are encoded in order to transmit the mobile service data, and multiplexing information on how the main service data and the mobile service data or various types of mobile service data are multiplexed. The information included in the transmission parameter is merely exemplary to facilitate the understanding of the present invention. And, the adding and deleting of the information included in the transmission parameter may be easily modified and changed by anyone skilled in the art. Therefore, the present invention is not limited to the examples proposed in the description set forth herein. Furthermore, the transmission parameters may be provided from the service multiplexer  100  to the transmitter  200 . Alternatively, the transmission parameters may also be set up by an internal controller (not shown) within the transmitter  200  or received from an external source. 
       Transmitter 
       [0090]      FIG. 3  illustrates a block diagram showing an example of the transmitter  200  according to an embodiment of the present invention. Herein, the transmitter  200  includes a demultiplexer  210 , a packet jitter mitigator  220 , a pre-processor  230 , a packet multiplexer  240 , a post-processor  250 , a synchronization (sync) multiplexer  260 , and a transmission unit  270 . Herein, when a data packet is received from the service multiplexer  100 , the demultiplexer  210  should identify whether the received data packet corresponds to a main service data packet, a mobile service data packet, or a null data packet. For example, the demultiplexer  210  uses the PID within the received data packet so as to identify the main service data packet and the mobile service data packet. Then, the demultiplexer  210  uses a transport_error_indicator field to identify the null data packet. The main service data packet identified by the demultiplexer  210  is outputted to the packet jitter mitigator  220 , the mobile service data packet is outputted to the pre-processor  230 , and the null data packet is discarded. If a transmission parameter is included in the null data packet, then the transmission parameter is first extracted and outputted to the corresponding block. Thereafter, the null data packet is discarded. 
         [0091]    The pre-processor  230  performs an additional encoding process of the mobile service data included in the service data packet, which is demultiplexed and outputted from the demultiplexer  210 . The pre-processor  230  also performs a process of configuring a data group so that the data group may be positioned at a specific place in accordance with the purpose of the data, which are to be transmitted on a transmission frame. This is to enable the mobile service data to respond swiftly and strongly against noise and channel changes. The pre-processor  230  may also refer to the transmission parameter when performing the additional encoding process. Also, the pre-processor  230  groups a plurality of mobile service data packets to configure a data group. Thereafter, known data, mobile service data, RS parity data, and MPEG header are allocated to pre-determined areas within the data group. 
         [0000]    Pre-Processor within Transmitter 
         [0092]      FIG. 4  illustrates a block diagram showing an example of the pre-processor  230  according to the present invention. The pre-processor  230  includes a data randomizer  301 , a RS frame encoder  302 , a block processor  303 , a group formatter  304 , a data deinterleaver  305 , a packet formatter  306 . The data randomizer  301  within the above-described pre-processor  230  randomizes the mobile service data packet including the mobile service data that is inputted through the demultiplexer  210 . Then, the data randomizer  301  outputs the randomized mobile service data packet to the RS frame encoder  302 . At this point, since the data randomizer  301  performs the randomizing process on the mobile service data, the randomizing process that is to be performed by the data randomizer  251  of the post-processor  250  on the mobile service data may be omitted. The data randomizer  301  may also discard the synchronization byte within the mobile service data packet and perform the randomizing process. This is an option that may be chosen by the system designer. In the example given in the present invention, the randomizing process is performed without discarding the synchronization byte within the mobile service data packet. 
         [0093]    The RS frame encoder  302  groups a plurality of mobile the synchronization byte within the mobile service data packets that is randomized and inputted, so as to create a RS frame. Then, the RS frame encoder  302  performs at least one of an error correction encoding process and an error detection encoding process in RS frame units. Accordingly, robustness may be provided to the mobile service data, thereby scattering group error that may occur during changes in a frequency environment, thereby enabling the enhanced data to respond to the frequency environment, which is extremely vulnerable and liable to frequent changes. Also, the RS frame encoder  302  groups a plurality of RS frame so as to create a super frame, thereby performing a row permutation process in super frame units. The row permutation process may also be referred to as a row interleaving process. Hereinafter, the process will be referred to as row permutation for simplicity. 
         [0094]    More specifically, when the RS frame encoder  302  performs the process of permuting each row of the super frame in accordance with a pre-determined rule, the position of the rows within the super frame before and after the row permutation process is changed. If the row permutation process is performed by super frame units, and even though the section having a plurality of errors occurring therein becomes very long, and even though the number of errors included in the RS frame, which is to be decoded, exceeds the extent of being able to be corrected, the errors become dispersed within the entire super frame. Thus, the decoding ability is even more enhanced as compared to a single RS frame. 
         [0095]    At this point, as an example of the present invention, RS-encoding is applied for the error correction encoding process, and a cyclic redundancy check (CRC) encoding is applied for the error detection process. When performing the RS-encoding, parity data that are used for the error correction are generated. And, when performing the CRC encoding, CRC data that are used for the error detection are generated. The RS encoding is one of forward error correction (FEC) methods. The FEC corresponds to a technique for compensating errors that occur during the transmission process. The CRC data generated by CRC encoding may be used for indicating whether or not the mobile service data have been damaged by the errors while being transmitted through the channel. In the present invention, a variety of error detection coding methods other than the CRC encoding method may be used, or the error correction coding method may be used to enhance the overall error correction ability of the receiving system. Herein, the RS frame encoder  302  refers to a pre-determined transmission parameter and/or the transmission parameter provided from the service multiplexer  100  so as to perform operations including RS frame configuration, RS encoding, CRC encoding, super frame configuration, and row permutation in super frame units. 
         [0000]    Pre-Processor within RS Frame Encoder 
         [0096]      FIG. 5(   a ) to  FIG. 5(   e ) illustrate error correction encoding and error detection encoding processed according to an embodiment of the present invention. More specifically, the RS frame encoder  302  first divides the inputted mobile service data bytes to units of a predetermined length. The predetermined length is decided by the system designer. And, in the example of the present invention, the predetermined length is equal to 187 bytes, and, therefore, the 187-byte unit will be referred to as a packet for simplicity. For example, when the mobile service data that are being inputted, as shown in  FIG. 5(   a ), correspond to a MPEG transport packet stream configured of 188-byte units, the first synchronization byte is removed, as shown in  FIG. 5(   b ), so as to configure a 187-byte unit. Herein, the synchronization byte is removed because each mobile service data packet has the same value. 
         [0097]    Herein, the process of removing the synchronization byte may be performed during a randomizing process of the data randomizer  301  in an earlier process. In this case, the process of the removing the synchronization byte by the RS frame encoder  302  may be omitted. Moreover, when adding synchronization bytes from the receiving system, the process may be performed by the data derandomizer instead of the RS frame decoder. Therefore, if a removable fixed byte (e.g., synchronization byte) does not exist within the mobile service data packet that is being inputted to the RS frame encoder  302 , or if the mobile service data that are being inputted are not configured in a packet format, the mobile service data that are being inputted are divided into 187-byte units, thereby configuring a packet for each 187-byte unit. 
         [0098]    Subsequently, as shown in  FIG. 5(   c ), N number of packets configured of 187 bytes is grouped to configure a RS frame. At this point, the RS frame is configured as a RS frame having the size of N(row)*187(column) bytes, in which 187-byte packets are sequentially inputted in a row direction. In order to simplify the description of the present invention, the RS frame configured as described above will also be referred to as a first RS frame. More specifically, only pure mobile service data are included in the first RS frame, which is the same as the structure configured of 187 N-byte rows. Thereafter, the mobile service data within the RS frame are divided into an equal size. Then, when the divided mobile service data are transmitted in the same order as the input order for configuring the RS frame, and when one or more errors have occurred at a particular point during the transmitting/receiving process, the errors are clustered (or gathered) within the RS frame as well. In this case, the receiving system uses a RS erasure decoding method when performing error correction decoding, thereby enhancing the error correction ability. At this point, the N number of columns within the N number of RS frame includes 187 bytes, as shown in  FIG. 5(   c ). 
         [0099]    In this case, a (Nc,Kc)-RS encoding process is performed on each column, so as to generate Nc−Kc(=P) number of parity bytes. Then, the newly generated P number of parity bytes is added after the very last byte of the corresponding column, thereby creating a column of (187+P) bytes. Herein, as shown in  FIG. 5(   c ), Kc is equal to 187 (i.e., Kc=187), and Nc is equal to 187+P (i.e., Nc=187+P). For example, when P is equal to 48, (235,187)-RS encoding process is performed so as to create a column of 235 bytes. When such RS encoding process is performed on all N number of columns, as shown in  FIG. 5(   c ), a RS frame having the size of N(row)*(187+P)(column) bytes may be created, as shown in  FIG. 5(   d ). In order to simplify the description of the present invention, the RS frame having the RS parity inserted therein will be referred to as s second RS frame. More specifically, the second RS frame having the structure of (187+P) rows configured of N bytes may be configured. 
         [0100]    As shown in  FIG. 5(   c ) or  FIG. 5(   d ), each row of the RS frame is configured of N bytes. However, depending upon channel conditions between the transmitting system and the receiving system, error may be included in the RS frame. When errors occur as described above, CRC data (or CRC code or CRC checksum) may be used on each row unit in order to verify whether error exists in each row unit. The RS frame encoder  302  may perform CRC encoding on the mobile service data being RS encoded so as to create (or generate) the CRC data. The CRC data being generated by CRC encoding may be used to indicate whether the mobile service data have been damaged while being transmitted through the channel. 
         [0101]    The present invention may also use different error detection encoding methods other than the CRC encoding method. Alternatively, the present invention may use the error correction encoding method to enhance the overall error correction ability of the receiving system.  FIG. 5(   e ) illustrates an example of using a 2-byte (i.e., 16-bit) CRC checksum as the CRC data. Herein, a 2-byte CRC checksum is generated for N number of bytes of each row, thereby adding the 2-byte CRC checksum at the end of the N number of bytes. Thus, each row is expanded to (N+2) number of bytes. Equation 1 below corresponds to an exemplary equation for generating a 2-byte CRC checksum for each row being configured of N number of bytes. 
         [0000]        g ( x )= x   16   +x   12   +x   5 +1  Equation 1 
         [0102]    The process of adding a 2-byte checksum in each row is only exemplary. Therefore, the present invention is not limited only to the example proposed in the description set forth herein. In order to simplify the understanding of the present invention, the RS frame having the RS parity and CRC checksum added therein will hereinafter be referred to as a third RS frame. More specifically, the third RS frame corresponds to (187+P) number of rows each configured of (N+2) number of bytes. As described above, when the process of RS encoding and CRC encoding are completed, the (N*187)-byte RS frame is expanded to a (N+2)*(187+P)-byte RS frame. Furthermore, the RS frame that is expanded, as shown in  FIG. 5(   e ), is inputted to the block processor  303 . 
         [0103]    As described above, the mobile service data encoded by the RS frame encoder  302  are inputted to the block processor  303 . The block processor  303  then encodes the inputted mobile service data at a coding rate of G/H (wherein, G is smaller than H (i.e., G&lt;H)) and then outputted to the group formatter  304 . More specifically, the block processor  303  divides the mobile service data being inputted in byte units into bit units. Then, the G number of bits is encoded to H number of bits. Thereafter, the encoded bits are converted back to byte units and then outputted. For example, if 1 bit of the input data is coded to 2 bits and outputted, then G is equal to 1 and H is equal to 2 (i.e., G=1 and H=2). Alternatively, if 1 bit of the input data is coded to 4 bits and outputted, then G is equal to 1 and H is equal to 4 (i.e., G=1 and H=4). Hereinafter, the former coding rate will be referred to as a coding rate of ½ (½-rate coding), and the latter coding rate will be referred to as a coding rate of ¼ (¼-rate coding), for simplicity. 
         [0104]    Herein, when using the ¼ coding rate, the coding efficiency is greater than when using the ½ coding rate, and may, therefore, provide greater and enhanced error correction ability. For such reason, when it is assumed that the data encoded at a ¼ coding rate in the group formatter  304 , which is located near the end portion of the system, are allocated to an area in which the receiving performance may be deteriorated, and that the data encoded at a ½ coding rate are allocated to an area having excellent receiving performance, the difference in performance may be reduced. At this point, the block processor  303  may also receive signaling information including transmission parameters. Herein, the signaling information may also be processed with either ½-rate coding or ¼-rate coding as in the step of processing mobile service data. Thereafter, the signaling information is also considered the same as the mobile service data and processed accordingly. 
         [0105]    Meanwhile, the group formatter inserts mobile service data that are outputted from the block processor  303  in corresponding areas within a data group, which is configured in accordance with a pre-defined rule. Also, with respect to the data deinterleaving process, each place holder or known data (or known data place holders) are also inserted in corresponding areas within the data group. At this point, the data group may be divided into at least one hierarchical area. Herein, the type of mobile service data being inserted in each area may vary depending upon the characteristics of each hierarchical area. Additionally, each area may, for example, be divided based upon the receiving performance within the data group. Furthermore, one data group may be configured to include a set of field synchronization data. 
         [0106]    In an example given in the present invention, a data group is divided into A, B, and C regions in a data configuration prior to data deinterleaving. At this point, the group formatter  304  allocates the mobile service data, which are inputted after being RS encoded and block encoded, to each of the corresponding regions by referring to the transmission parameter.  FIG. 6A  illustrates an alignment of data after being data interleaved and identified, and  FIG. 6B  illustrates an alignment of data before being data interleaved and identified. More specifically, a data structure identical to that shown in  FIG. 6A  is transmitted to a receiving system. Also, the data group configured to have the same structure as the data structure shown in  FIG. 6A  is inputted to the data deinterleaver  305 . 
         [0107]    As described above,  FIG. 6A  illustrates a data structure prior to data deinterleaving that is divided into 3 regions, such as region A, region B, and region C. Also, in the present invention, each of the regions A to C is further divided into a plurality of regions. Referring to  FIG. 6A , region A is divided into 5 regions (A 1  to A 5 ), region B is divided into 2 regions (B 1  and B 2 ), and region C is divided into 3 regions (C 1  to C 3 ). Herein, regions A to C are identified as regions having similar receiving performances within the data group. Herein, the type of mobile service data, which are inputted, may also vary depending upon the characteristic of each region. 
         [0108]    In the example of the present invention, the data structure is divided into regions A to C based upon the level of interference of the main service data. Herein, the data group is divided into a plurality of regions to be used for different purposes. More specifically, a region of the main service data having no interference or a very low interference level may be considered to have a more resistant (or stronger) receiving performance as compared to regions having higher interference levels. Additionally, when using a system inserting and transmitting known data in the data group, and when consecutively long known data are to be periodically inserted in the mobile service data, the known data having a predetermined length may be periodically inserted in the region having no interference from the main service data (e.g., region A). However, due to interference from the main service data, it is difficult to periodically insert known data and also to insert consecutively long known data to a region having interference from the main service data (e.g., region B and region C). 
         [0109]    Hereinafter, examples of allocating data to region A (A 1  to A 5 ), region B (B 1  and B 2 ), and region C (C 1  to C 3 ) will now be described in detail with reference to  FIG. 6A . The data group size, the number of hierarchically divided regions within the data group and the size of each region, and the number of mobile service data bytes that can be inserted in each hierarchically divided region of  FIG. 6A  are merely examples given to facilitate the understanding of the present invention. Herein, the group formatter  304  creates a data group including places in which field synchronization data bytes are to be inserted, so as to create the data group that will hereinafter be described in detail. 
         [0110]    More specifically, region A is a region within the data group in which a long known data sequence may be periodically inserted, and in which includes regions wherein the main service data are not mixed (e.g., A 1  to A 5 ). Also, region A includes a region (e.g., A 1 ) located between a field synchronization region and the region in which the first known data sequence is to be inserted. The field synchronization region has the length of one segment (i.e., 832 symbols) existing in an ATSC system. 
         [0111]    For example, referring to  FIG. 6A , 2428 bytes of the mobile service data may be inserted in region A 1 , 2580 bytes may be inserted in region A 2 , 2772 bytes may be inserted in region A 3 , 2472 bytes may be inserted in region A 4 , and 2772 bytes may be inserted in region A 5 . Herein, trellis initialization data or known data, MPEG header, and RS parity are not included in the mobile service data. As described above, when region A includes a known data sequence at both ends, the receiving system uses channel information that can obtain known data or field synchronization data, so as to perform equalization, thereby providing enforced equalization performance. 
         [0112]    Also, region B includes a region located within 8 segments at the beginning of a field synchronization region within the data group (chronologically placed before region A 1 ) (e.g., region B 1 ), and a region located within 8 segments behind the very last known data sequence which is inserted in the data group (e.g., region B 2 ). For example, 930 bytes of the mobile service data may be inserted in the region B 1 , and 1350 bytes may be inserted in region B 2 . Similarly, trellis initialization data or known data, MPEG header, and RS parity are not included in the mobile service data. In case of region B, the receiving system may perform equalization by using channel information obtained from the field synchronization region. Alternatively, the receiving system may also perform equalization by using channel information that may be obtained from the last known data sequence, thereby enabling the system to respond to the channel changes. 
         [0113]    Region C includes a region located within 30 segments including and preceding the 9 th  segment of the field synchronization region (chronologically located before region A) (e.g., region C 1 ), a region located within 12 segments including and following the 9 th  segment of the very last known data sequence within the data group (chronologically located after region A) (e.g., region C 2 ), and a region located in 32 segments after the region C 2  (e.g., region C 3 ). For example, 1272 bytes of the mobile service data may be inserted in the region C 1 , 1560 bytes may be inserted in region C 2 , and 1312 bytes may be inserted in region C 3 . Similarly, trellis initialization data or known data, MPEG header, and RS parity are not included in the mobile service data. Herein, region C (e.g., region C 1 ) is located chronologically earlier than (or before) region A. 
         [0114]    Since region C (e.g., region C 1 ) is located further apart from the field synchronization region which corresponds to the closest known data region, the receiving system may use the channel information obtained from the field synchronization data when performing channel equalization. Alternatively, the receiving system may also use the most recent channel information of a previous data group. Furthermore, in region C (e.g., region C 2  and region C 3 ) located before region A, the receiving system may use the channel information obtained from the last known data sequence to perform equalization. However, when the channels are subject to fast and frequent changes, the equalization may not be performed perfectly. Therefore, the equalization performance of region C may be deteriorated as compared to that of region B. 
         [0115]    When it is assumed that the data group is allocated with a plurality of hierarchically divided regions, as described above, the block processor  303  may encode the mobile service data, which are to be inserted to each region based upon the characteristic of each hierarchical region, at a different coding rate. For example, the block processor  303  may encode the mobile service data, which are to be inserted in regions A 1  to A 5  of region A, at a coding rate of ½. Then, the group formatter  304  may insert the ½-rate encoded mobile service data to regions A 1  to A 5 . 
         [0116]    The block processor  303  may encode the mobile service data, which are to be inserted in regions B 1  and B 2  of region B, at a coding rate of ¼ having higher error correction ability as compared to the ½-coding rate. Then, the group formatter  304  inserts the ¼-rate coded mobile service data in region B 1  and region B 2 . Furthermore, the block processor  303  may encode the mobile service data, which are to be inserted in regions C 1  to C 3  of region C, at a coding rate of ¼ or a coding rate having higher error correction ability than the ¼-coding rate. Then, the group formatter  304  may either insert the encoded mobile service data to regions C 1  to C 3 , as described above, or leave the data in a reserved region for future usage. 
         [0117]    In addition, the group formatter  304  also inserts supplemental data, such as signaling information that notifies the overall transmission information, other than the mobile service data in the data group. Also, apart from the encoded mobile service data outputted from the block processor  303 , the group formatter  304  also inserts MPEG header place holders, non-systematic RS parity place holders, main service data place holders, which are related to data deinterleaving in a later process, as shown in  FIG. 6A . Herein, the main service data place holders are inserted because the mobile service data bytes and the main service data bytes are alternately mixed with one another in regions B and C based upon the input of the data deinterleaver, as shown in  FIG. 6A . For example, based upon the data outputted after data deinterleaving, the place holder for the MPEG header may be allocated at the very beginning of each packet. 
         [0118]    Furthermore, the group formatter  304  either inserts known data generated in accordance with a pre-determined method or inserts known data place holders for inserting the known data in a later process. Additionally, place holders for initializing the trellis encoding module  256  are also inserted in the corresponding regions. For example, the initialization data place holders may be inserted in the beginning of the known data sequence. Herein, the size of the mobile service data that can be inserted in a data group may vary in accordance with the sizes of the trellis initialization place holders or known data (or known data place holders), MPEG header place holders, and RS parity place holders. 
         [0119]    The output of the group formatter  304  is inputted to the data deinterleaver  305 . And, the data deinterleaver  305  deinterleaves data by performing an inverse process of the data interleaver on the data and place holders within the data group, which are then outputted to the packet formatter  306 . More specifically, when the data and place holders within the data group configured, as shown in  FIG. 6A , are deinterleaved by the data deinterleaver  305 , the data group being outputted to the packet formatter  306  is configured to have the structure shown in  FIG. 6B . 
         [0120]    The packet formatter  306  removes the main service data place holders and the RS parity place holders that were allocated for the deinterleaving process from the deinterleaved data being inputted. Then, the packet formatter  306  groups the remaining portion and replaces the 4-byte MPEG header place holder with an MPEG header having a null packet PID (or an unused PID from the main service data packet). Also, when the group formatter  304  inserts known data place holders, the packet formatter  306  may insert actual known data in the known data place holders, or may directly output the known data place holders without any modification in order to make replacement insertion in a later process. Thereafter, the packet formatter  306  identifies the data within the packet-formatted data group, as described above, as a 188-byte unit mobile service data packet (i.e., MPEG TS packet), which is then provided to the packet multiplexer  240 . 
         [0121]    The packet multiplexer  240  multiplexes the mobile service data packet outputted from the pre-processor  230  and the main service data packet outputted from the packet jitter mitigator  220  in accordance with a pre-defined multiplexing method. Then, the packet multiplexer  240  outputs the multiplexed data packets to the data randomizer  251  of the post-processor  250 . Herein, the multiplexing method may vary in accordance with various variables of the system design. One of the multiplexing methods of the packet formatter  240  consists of providing a burst section along a time axis, and, then, transmitting a plurality of data groups during a burst-on section within the burst section, and transmitting only the main service data during the burst-off section within the burst section. Herein, the burst section indicates the section starting from the beginning of the current burst until the beginning of the next burst. 
         [0122]    At this point, the main service data may be transmitted during the burst-on section. The packet multiplexer  240  refers to the transmission parameter, such as information on the burst size or the burst period, so as to be informed of the number of data groups and the period of the data groups included in a single burst. Herein, the mobile service data and the main service data may co-exist in the burst-on section, and only the main service data may exist in the burst-off section. Therefore, a main data service section transmitting the main service data may exist in both burst-on and burst-off sections. At this point, the main data service section within the burst-on section and the number of main data service packets included in the burst-off section may either be different from one another or be the same. 
         [0123]    When the mobile service data are transmitted in a burst structure, in the receiving system receiving only the mobile service data turns the power on only during the burst section, thereby receiving the corresponding data. Alternatively, in the section transmitting only the main service data, the power is turned off so that the main service data are not received in this section. Thus, the power consumption of the receiving system may be reduced. 
       DETAILED EMBODIMENTS OF THE RS FRAME STRUCTURE AND PACKET MULTIPLEXING 
       [0124]    Hereinafter, detailed embodiments of the pre-processor  230  and the packet multiplexer  240  will now be described. According to an embodiment of the present invention, the N value corresponding to the length of a row, which is included in the RS frame that is configured by the RS frame encoder  302 , is set to 538. Accordingly, the RS frame encoder  302  receives 538 transport stream (TS) packets so as to configure a first RS frame having the size of 538*187 bytes. Thereafter, as described above, the first RS frame is processed with a (235,187)-RS encoding process so as to configure a second RS frame having the size of 538*235 bytes. Finally, the second RS frame is processed with generating a 16-bit checksum so as to configure a third RS frame having the sizes of 540*235. 
         [0125]    Meanwhile, as shown in  FIG. 6A , the sum of the number of bytes of regions A 1  to A 5  of region A, in which ½-rate encoded mobile service data are to be inserted, among the plurality of regions within the data group is equal to 13024 bytes (=2428+2580+2772+2472+2772 bytes). Herein, the number of byte prior to performing the ½-rate encoding process is equal to 6512 (=13024/2). On the other hand, the sum of the number of bytes of regions B 1  and B 2  of region B, in which ¼-rate encoded mobile service data are to be inserted, among the plurality of regions within the data group is equal to 2280 bytes (=930+1350 bytes). Herein, the number of byte prior to performing the ¼-rate encoding process is equal to 570 (=2280/4). 
         [0126]    In other words, when 7082 bytes of mobile service data are inputted to the block processor  303 , 6512 byte are expanded to 13024 bytes by being ½-rate encoded, and 570 bytes are expanded to 2280 bytes by being ¼-rate encoded. Thereafter, the block processor  303  inserts the mobile service data expanded to 13024 bytes in regions A 1  to A 5  of region A and, also, inserts the mobile service data expanded to 2280 bytes in regions B 1  and B 2  of region B. Herein, the 7082 bytes of mobile service data being inputted to the block processor  303  may be divided into an output of the RS frame encoder  302  and signaling information. In the present invention, among the 7082 bytes of mobile service data, 7050 bytes correspond to the output of the RS frame encoder  302 , and the remaining 32 bytes correspond to the signaling information data. Then, ½-rate encoding or ¼-rate encoding is performed on the corresponding data bytes. 
         [0127]    Meanwhile, a RS frame being processed with RS encoding and CRC encoding from the RS frame encoder  302  is configured of 540*235 bytes, in other words, 126900 bytes. The 126900 bytes are divided by 7050-byte units along the time axis, so as to produce 18 7050-byte units. Thereafter, a 32-byte unit of signaling information data is added to the 7050-byte unit mobile service data being outputted from the RS frame encoder  302 . Subsequently, the RS frame encoder  302  performs ½-rate encoding or ¼-rate encoding on the corresponding data bytes, which are then outputted to the group formatter  304 . Accordingly, the group formatter  304  inserts the ½-rate encoded data in region A and the ¼-rate encoded data in region B. 
         [0128]    The process of deciding an N value that is required for configuring the RS frame from the RS frame encoder  302  will now be described in detail. More specifically, the size of the final RS frame (i.e., the third RS frame), which is RS encoded and CRC encoded from the RS frame encoder  302 , which corresponds to (N+2)*235 bytes should be allocated to X number of groups, wherein X is an integer. Herein, in a single data group, 7050 data bytes prior to being encoded are allocated. Therefore, if the (N+2)*235 bytes are set to be the exact multiple of 7050(=30*235), the output data of the RS frame encoder  302  may be efficiently allocated to the data group. According to an embodiment of the present invention, the value of N is decided so that (N+2) becomes a multiple of 30. For example, in the present invention, N is equal to 538, and (N+2)(=540) divided by 30 is equal to 18. This indicates that the mobile service data within one RS frame are processed with either ½-rate encoding or ¼-rate encoding. The encoded mobile service data are then allocated to 18 data groups. 
         [0129]      FIG. 7  illustrates a process of dividing the RS frame according to the present invention. More specifically, the RS frame having the size of (N+2)*235 is divided into 30*235 byte blocks. Then, the divided blocks are mapped to a single group. In other words, the data of a block having the size of 30*235 bytes are processed with one of a ½-rate encoding process and a ¼-rate encoding process and are, then, inserted in a data group. Thereafter, the data group having corresponding data and place holders inserted in each hierarchical region divided by the group formatter  304  passes through the data deinterleaver  305  and the packet formatter  306  so as to be inputted to the packet multiplexer  240 . 
         [0130]      FIG. 8  illustrates exemplary operations of a packet multiplexer for transmitting the data group according to the present invention. More specifically, the packet multiplexer  240  multiplexes a field including a data group, in which the mobile service data and main service data are mixed with one another, and a field including only the main service data. Thereafter, the packet multiplexer  240  outputs the multiplexed fields to the data randomizer  251 . At this point, in order to transmit the RS frame having the size of 540*235 bytes, 18 data groups should be transmitted. Herein, each data group includes field synchronization data, as shown in  FIG. 6A . Therefore, the 18 data groups are transmitted during 18 field sections, and the section during which the 18 data groups are being transmitted corresponds to the burst-on section. 
         [0131]    In each field within the burst-on section, a data group including field synchronization data is multiplexed with main service data, which are then outputted. For example, in the embodiment of the present invention, in each field within the burst-on section, a data group having the size of 118 segments is multiplexed with a set of main service data having the size of 194 segments. Referring to  FIG. 8 , during the burst-on section (i.e., during the 18 field sections), a field including 18 data groups is transmitted. Then, during the burst-off section that follows (i.e., during the 12 field sections), a field consisting only of the main service data is transmitted. Subsequently, during a subsequent burst-on section, 18 fields including 18 data groups are transmitted. And, during the following burst-off section, 12 fields consisting only of the main service data are transmitted. 
         [0132]    Furthermore, in the present invention, the same type of data service may be provided in the first burst-on section including the first 18 data groups and in the second burst-on section including the next 18 data groups. Alternatively, different types of data service may be provided in each burst-on section. For example, when it is assumed that different data service types are provided to each of the first burst-on section and the second burst-on section, and that the receiving system wishes to receive only one type of data service, the receiving system turns the power on only during the corresponding burst-on section including the desired data service type so as to receive the corresponding 18 data fields. Then, the receiving system turns the power off during the remaining 42 field sections so as to prevent other data service types from being received. Thus, the amount of power consumption of the receiving system may be reduced. In addition, the receiving system according to the present invention is advantageous in that one RS frame may be configured from the 18 data groups that are received during a single burst-on section. 
         [0133]    According to the present invention, the number of data groups included in a burst-on section may vary based upon the size of the RS frame, and the size of the RS frame varies in accordance with the value N. More specifically, by adjusting the value N, the number of data groups within the burst section may be adjusted. Herein, in an example of the present invention, the (235,187)-RS encoding process adjusts the value N during a fixed state. Furthermore, the size of the mobile service data that can be inserted in the data group may vary based upon the sizes of the trellis initialization data or known data, the MPEG header, and the RS parity, which are inserted in the corresponding data group. 
         [0134]    Meanwhile, since a data group including mobile service data in-between the data bytes of the main service data during the packet multiplexing process, the shifting of the chronological position (or place) of the main service data packet becomes relative. Also, a system object decoder (i.e., MPEG decoder) for processing the main service data of the receiving system, receives and decodes only the main service data and recognizes the mobile service data packet as a null data packet. Therefore, when the system object decoder of the receiving system receives a main service data packet that is multiplexed with the data group, a packet jitter occurs. 
         [0135]    At this point, since a multiple-level buffer for the video data exists in the system object decoder and the size of the buffer is relatively large, the packet jitter generated from the packet multiplexer  240  does not cause any serious problem in case of the video data. However, since the size of the buffer for the audio data is relatively small, the packet jitter may cause considerable problem. More specifically, due to the packet jitter, an overflow or underflow may occur in the buffer for the main service data of the receiving system (e.g., the buffer for the audio data). Therefore, the packet jitter mitigator  220  re-adjusts the relative position of the main service data packet so that the overflow or underflow does not occur in the system object decoder. 
         [0136]    In the present invention, examples of repositioning places for the audio data packets within the main service data in order to minimize the influence on the operations of the audio buffer will be described in detail. The packet jitter mitigator  220  repositions the audio data packets in the main service data section so that the audio data packets of the main service data can be as equally and uniformly aligned and positioned as possible. The standard for repositioning the audio data packets in the main service data performed by the packet jitter mitigator  220  will now be described. Herein, it is assumed that the packet jitter mitigator  220  knows the same multiplexing information as that of the packet multiplexer  240 , which is placed further behind the packet jitter mitigator  220 . 
         [0137]    Firstly, if one audio data packet exists in the main service data section (e.g., the main service data section positioned between two data groups) within the burst-on section, the audio data packet is positioned at the very beginning of the main service data section. Alternatively, if two audio data packets exist in the corresponding data section, one audio data packet is positioned at the very beginning and the other audio data packet is positioned at the very end of the main service data section. Further, if more than three audio data packets exist, one audio data packet is positioned at the very beginning of the main service data section, another is positioned at the very end of the main service data section, and the remaining audio data packets are equally positioned between the first and last audio data packets. Secondly, during the main service data section placed immediately before the beginning of a burst-on section (i.e., during a burst-off section), the audio data packet is placed at the very end of the corresponding section. 
         [0138]    Thirdly, during a main service data section within the burst-off section after the burst-on section, the audio data packet is positioned at the very end of the main service data section. Finally, the data packets other than audio data packets are positioned in accordance with the inputted order in vacant spaces (i.e., spaces that are not designated for the audio data packets). Meanwhile, when the positions of the main service data packets are relatively re-adjusted, associated program clock reference (PCR) values may also be modified accordingly. The PCR value corresponds to a time reference value for synchronizing the time of the MPEG decoder. Herein, the PCR value is inserted in a specific region of a TS packet and then transmitted. 
         [0139]    In the example of the present invention, the packet jitter mitigator  220  also performs the operation of modifying the PCR value. The output of the packet jitter mitigator  220  is inputted to the packet multiplexer  240 . As described above, the packet multiplexer  240  multiplexes the main service data packet outputted from the packet jitter mitigator  220  with the mobile service data packet outputted from the pre-processor  230  into a burst structure in accordance with a pre-determined multiplexing rule. Then, the packet multiplexer  240  outputs the multiplexed data packets to the data randomizer  251  of the post-processor  250 . 
         [0140]    If the inputted data correspond to the main service data packet, the data randomizer  251  performs the same randomizing process as that of the conventional randomizer. More specifically, the synchronization byte within the main service data packet is deleted. Then, the remaining 187 data bytes are randomized by using a pseudo random byte generated from the data randomizer  251 . Thereafter, the randomized data are outputted to the RS encoder/non-systematic RS encoder  252 . 
         [0141]    On the other hand, if the inputted data correspond to the mobile service data packet, the data randomizer  251  may randomize only a portion of the data packet. For example, if it is assumed that a randomizing process has already been performed in advance on the mobile service data packet by the pre-processor  230 , the data randomizer  251  deletes the synchronization byte from the 4-byte MPEG header included in the mobile service data packet and, then, performs the randomizing process only on the remaining 3 data bytes of the MPEG header. Thereafter, the randomized data bytes are outputted to the RS encoder/non-systematic RS encoder  252 . More specifically, the randomizing process is not performed on the remaining portion of the mobile service data excluding the MPEG header. In other words, the remaining portion of the mobile service data packet is directly outputted to the RS encoder/non-systematic RS encoder  252  without being randomized. Also, the data randomizer  251  may or may not perform a randomizing process on the known data (or known data place holders) and the initialization data place holders included in the mobile service data packet. 
         [0142]    The RS encoder/non-systematic RS encoder  252  performs an RS encoding process on the data being randomized by the data randomizer  251  or on the data bypassing the data randomizer  251 , so as to add 20 bytes of RS parity data. Thereafter, the processed data are outputted to the data interleaver  253 . Herein, if the inputted data correspond to the main service data packet, the RS encoder/non-systematic RS encoder  252  performs the same systematic RS encoding process as that of the conventional broadcasting system, thereby adding the 20-byte RS parity data at the end of the 187-byte data. Alternatively, if the inputted data correspond to the mobile service data packet, the RS encoder/non-systematic RS encoder  252  performs a non-systematic RS encoding process. At this point, the 20-byte RS parity data obtained from the non-systematic RS encoding process are inserted in a pre-decided parity byte place within the mobile service data packet. 
         [0143]    The data interleaver  253  corresponds to a byte unit convolutional interleaver. The output of the data interleaver  253  is inputted to the parity replacer  254  and to the non-systematic RS encoder  255 . Meanwhile, a process of initializing a memory within the trellis encoding module  256  is primarily required in order to decide the output data of the trellis encoding module  256 , which is located after the parity replacer  254 , as the known data pre-defined according to an agreement between the receiving system and the transmitting system. More specifically, the memory of the trellis encoding module  256  should first be initialized before the received known data sequence is trellis-encoded. At this point, the beginning portion of the known data sequence that is received corresponds to the initialization data place holder and not to the actual known data. Herein, the initialization data place holder has been included in the data by the group formatter within the pre-processor  230  in an earlier process. Therefore, the process of generating initialization data and replacing the initialization data place holder of the corresponding memory with the generated initialization data are required to be performed immediately before the inputted known data sequence is trellis-encoded. 
         [0144]    Additionally, a value of the trellis memory initialization data is decided and generated based upon a memory status of the trellis encoding module  256 . Further, due to the newly replaced initialization data, a process of newly calculating the RS parity and replacing the RS parity, which is outputted from the data interleaver  253 , with the newly calculated RS parity is required. Therefore, the non-systematic RS encoder  255  receives the mobile service data packet including the initialization data place holders, which are to be replaced with the actual initialization data, from the data interleaver  253  and also receives the initialization data from the trellis encoding module  256 . 
         [0145]    Among the inputted mobile service data packet, the initialization data place holders are replaced with the initialization data, and the RS parity data that are added to the mobile service data packet are removed and processed with non-systematic RS encoding. Thereafter, the new RS parity obtained by performing the non-systematic RS encoding process is outputted to the parity replacer  255 . Accordingly, the parity replacer  255  selects the output of the data interleaver  253  as the data within the mobile service data packet, and the parity replacer  255  selects the output of the non-systematic RS encoder  255  as the RS parity. The selected data are then outputted to the trellis encoding module  256 . 
         [0146]    Meanwhile, if the main service data packet is inputted or if the mobile service data packet, which does not include any initialization data place holders that are to be replaced, is inputted, the parity replacer  254  selects the data and RS parity that are outputted from the data interleaver  253 . Then, the parity replacer  254  directly outputs the selected data to the trellis encoding module  256  without any modification. The trellis encoding module  256  converts the byte-unit data to symbol units and performs a 12-way interleaving process so as to trellis-encode the received data. Thereafter, the processed data are outputted to the synchronization multiplexer  260 . 
         [0147]    The synchronization multiplexer  260  inserts a field synchronization signal and a segment synchronization signal to the data outputted from the trellis encoding module  256  and, then, outputs the processed data to the pilot inserter  271  of the transmission unit  270 . Herein, the data having a pilot inserted therein by the pilot inserter  271  are modulated by the modulator  272  in accordance with a pre-determined modulating method (e.g., a VSB method). Thereafter, the modulated data are transmitted to each receiving system though the radio frequency (RF) up-converter  273 . 
       Block Processor 
       [0148]      FIG. 9  illustrates a block diagram showing a structure of a block processor according to the present invention. Herein, the block processor includes a byte-bit converter  401 , a symbol encoder  402 , a symbol interleaver  403 , and a symbol-byte converter  404 . The byte-bit converter  401  divides the mobile service data bytes that are inputted from the RS frame encoder  112  into bits, which are then outputted to the symbol encoder  402 . The byte-bit converter  401  may also receive signaling information including transmission parameters. The signaling information data bytes are also divided into bits so as to be outputted to the symbol encoder  402 . Herein, the signaling information including transmission parameters may be processed with the same data processing step as that of the mobile service data. More specifically, the signaling information may be inputted to the block processor  303  by passing through the data randomizer  301  and the RS frame encoder  302 . Alternatively, the signaling information may also be directly outputted to the block processor  303  without passing though the data randomizer  301  and the RS frame encoder  302 . 
         [0149]    The symbol encoder  402  corresponds to a G/H-rate encoder encoding the inputted data from G bits to H bits and outputting the data encoded at the coding rate of G/H. According to the embodiment of the present invention, it is assumed that the symbol encoder  402  performs either a coding rate of ½ (also referred to as a ½-rate encoding process) or an encoding process at a coding rate of ¼ (also referred to as a ¼-rate encoding process). The symbol encoder  402  performs one of ½-rate encoding and ¼-rate encoding on the inputted mobile service data and signaling information. Thereafter, the signaling information is also recognized as the mobile service data and processed accordingly. 
         [0150]    In case of performing the ½-rate coding process, the symbol encoder  402  receives 1 bit and encodes the received 1 bit to 2 bits (i.e., 1 symbol). Then, the symbol encoder  402  outputs the processed 2 bits (or 1 symbol). On the other hand, in case of performing the ¼-rate encoding process, the symbol encoder  402  receives 1 bit and encodes the received 1 bit to 4 bits (i.e., 2 symbols). Then, the symbol encoder  402  outputs the processed 4 bits (or 2 symbols). 
         [0151]      FIG. 10  illustrates a detailed block diagram of the symbol encoder  402  shown in  FIG. 9 . The symbol encoder  402  includes two delay units  501  and  503  and three adders  502 ,  504 , and  505 . Herein, the symbol encoder  402  encodes an input data bit U and outputs the coded bit U to 4 bits (u 0  to u 4 ). At this point, the data bit U is directly outputted as uppermost bit u 0  and simultaneously encoded as lower bit u 1 u 2 u 3  and then outputted. More specifically, the input data bit U is directly outputted as the uppermost bit u 0  and simultaneously outputted to the first and third adders  502  and  505 . The first adder  502  adds the input data bit U and the output bit of the first delay unit  501  and, then, outputs the added bit to the second delay unit  503 . Then, the data bit delayed by a pre-determined time (e.g., by 1 clock) in the second delay unit  503  is outputted as lower bit u 1  and simultaneously fed-back to the first delay unit  501 . The first delay unit  501  delays the data bit fed-back from the second delay unit  503  by a pre-determined time (e.g., by 1 clock). Then, the first delay unit  501  outputs the delayed data bit to the first adder  502  and the second adder  504 . The second adder  504  adds the data bits outputted from the first and second delay units  501  and  503  as a lower bit u 2 . The third adder  505  adds the input data bit U and the output of the second delay unit  503  and outputs the added data bit as a lower bit u 3 . 
         [0152]    At this point, if the input data bit U corresponds to data encoded at a ½-coding rate, the symbol encoder  402  configures a symbol with u 1 u 0  bits from the 4 output bits u 0 u 1 u 2 u 3 . Then, the symbol encoder  402  outputs the newly configured symbol. Alternatively, if the input data bit U corresponds to data encoded at a ¼-coding rate, the symbol encoder  402  configures and outputs a symbol with bits u 1 u 0  and, then, configures and outputs another symbol with bits u 2 u 3 . According to another embodiment of the present invention, if the input data bit U corresponds to data encoded at a ¼-coding rate, the symbol encoder  402  may also configure and output a symbol with bits u 1 u 0 , and then repeat the process once again and output the corresponding bits. According to yet another embodiment of the present invention, the symbol encoder outputs all four output bits U u 0 u 1 u 2 u 3 . Then, when using the ½-coding rate, the symbol interleaver  403  located behind the symbol encoder  402  selects only the symbol configured of bits u 1 u 0  from the four output bits u 0 u 1 u 2 u 3 . Alternatively, when using the ¼-coding rate, the symbol interleaver  403  may select the symbol configured of bits u 1 u 0  and then select another symbol configured of bits u 2 u 3 . According to another embodiment, when using the ¼-coding rate, the symbol interleaver  403  may repeatedly select the symbol configured of bits u 1 u 0 . 
         [0153]    The output of the symbol encoder  402  is inputted to the symbol interleaver  403 . Then, the symbol interleaver  403  performs block interleaving in symbol units on the data outputted from the symbol encoder  402 . Any interleaver performing structural rearrangement (or realignment) may be applied as the symbol interleaver  403  of the block processor. However, in the present invention, a variable length symbol interleaver that can be applied even when a plurality of lengths is provided for the symbol, so that its order may be rearranged, may also be used. 
         [0154]      FIG. 11  illustrates a symbol interleaver according to an embodiment of the present invention. Herein, the symbol interleaver according to the embodiment of the present invention corresponds to a variable length symbol interleaver that may be applied even when a plurality of lengths is provided for the symbol, so that its order may be rearranged. Particularly,  FIG. 11  illustrates an example of the symbol interleaver when K=6 and L=8. Herein, K indicates a number of symbols that are outputted for symbol interleaving from the symbol encoder  402 . And, L represents a number of symbols that are actually interleaved by the symbol interleaver  403 . 
         [0155]    In the present invention, the symbol intereleaver  403  should satisfy the conditions of L=2 n  (wherein n is an integer) and of L≧K. If there is a difference in value between K and L, (L−K) number of null (or dummy) symbols is added, thereby creating an interleaving pattern. Therefore, K becomes a block size of the actual symbols that are inputted to the symbol interleaver  403  in order to be interleaved. L becomes an interleaving unit when the interleaving process is performed by an interleaving pattern created from the symbol interleaver  403 . The example of what is described above is illustrated in  FIG. 11 . 
         [0156]    More specifically,  FIG. 11(   a ) to  FIG. 11(   c ) illustrate a variable length interleaving process of a symbol interleaver shown in  FIG. 9 . The number of symbols outputted from the symbol encoder  402  in order to be interleaved is equal to 6 (i.e., K=6). In other words, 6 symbols are outputted from the symbol encoder  402  in order to be interleaved. And, the actual interleaving unit (L) is equal to 8 symbols. Therefore, as shown in  FIG. 11(   a ), 2 symbols are added to the null (or dummy) symbol, thereby creating the interleaving pattern. Equation 2 shown below described the process of sequentially receiving K number of symbols, the order of which is to be rearranged, and obtaining an L value satisfying the conditions of L=2 n  (wherein n is an integer) and of L≧K, thereby creating the interleaving so as to realign (or rearrange) the symbol order. 
         [0157]    In relation to all places, wherein 0≦i≦L−1, 
         [0000]        P ( i )={ S×i× ( i+ 1)/2} mod  L   Equation 2 
         [0158]    Herein, L≧K, L=2 n , and n and S are integers. Referring to  FIG. 11 , it is assumed that S is equal to 89, and that L is equal to 8, and  FIG. 11  illustrates the created interleaving pattern and an example of the interleaving process. As shown in  FIG. 11(   b ), the order of K number of input symbols and (L−K) number of null symbols is rearranged by using the above-mentioned Equation 2. Then, as shown in  FIG. 11(   c ), the null byte places are removed, so as to rearrange the order, by using Equation 3 shown below. Thereafter, the symbol that is interleaved by the rearranged order is then outputted to the symbol-byte converter. 
         [0000]      if  P ( i )&gt; K− 1, then P(i) place is removed and rearranged  Equation 3 
         [0159]    Subsequently, the symbol-byte converter  404  converts to bytes the mobile service data symbols, having the rearranging of the symbol order completed and then outputted in accordance with the rearranged order, and thereafter outputs the converted bytes to the group formatter  304 . 
         [0160]      FIG. 12A  illustrates a block diagram showing the structure of a block processor according to another embodiment of the present invention. Herein, the block processor includes an interleaving unit  610  and a block formatter  620 . The interleaving unit  610  may include a byte-symbol converter  611 , a symbol-byte converter  612 , a symbol interleaver  613 , and a symbol-byte converter  614 . Herein, the symbol interleaver  613  may also be referred to as a block interleaver. 
         [0161]    The byte-symbol converter  611  of the interleaving unit  610  converts the mobile service data X outputted in byte units from the RS frame encoder  302  to symbol units. Then, the byte-symbol converter  611  outputs the converted mobile service data symbols to the symbol-byte converter  612  and the symbol interleaver  613 . More specifically, the byte-symbol converter  611  converts each 2 bits of the inputted mobile service data byte (=8 bits) to 1 symbol and outputs the converted symbols. This is because the input data of the trellis encoding module  256  consist of symbol units configured of 2 bits. The relationship between the block processor  303  and the trellis encoding module  256  will be described in detail in a later process. At this point, the byte-symbol converter  611  may also receive signaling information including transmission parameters. Furthermore, the signaling information bytes may also be divided into symbol units and then outputted to the symbol-byte converter  612  and the symbol interleaver  613 . 
         [0162]    The symbol-byte converter  612  groups 4 symbols outputted from the byte-symbol converter  611  so as to configure a byte. Thereafter, the converted data bytes are outputted to the block formatter  620 . Herein, each of the symbol-byte converter  612  and the byte-symbol converter  611  respectively performs an inverse process on one another. Therefore, the yield of these two blocks is offset. Accordingly, as shown in  FIG. 12B , the input data X bypass the byte-symbol converter  611  and the symbol-byte converter  612  and are directly inputted to the block formatter  620 . More specifically, the interleaving unit  610  of  FIG. 12B  has a structure equivalent to that of the interleaving unit shown in  FIG. 12A . Therefore, the same reference numerals will be used in  FIG. 12A  and  FIG. 12B . 
         [0163]    The symbol interleaver  613  performs block interleaving in symbol units on the data that are outputted from the byte-symbol converter  611 . Subsequently, the symbol interleaver  613  outputs the interleaved data to the symbol-byte converter  614 . Herein, any type of interleaver that can rearrange the structural order may be used as the symbol interleaver  613  of the present invention. In the example given in the present invention, a variable length interleaver that may be applied for symbols having a wide range of lengths, the order of which is to be rearranged. For example, the symbol interleaver of  FIG. 11  may also be used in the block processor shown in  FIG. 12A  and  FIG. 12B . 
         [0164]    The symbol-byte converter  614  outputs the symbols having the rearranging of the symbol order completed, in accordance with the rearranged order. Thereafter, the symbols are grouped to be configured in byte units, which are then outputted to the block formatter  620 . More specifically, the symbol-byte converter  614  groups 4 symbols outputted from the symbol interleaver  613  so as to configure a data byte. As shown in  FIG. 13 , the block formatter  620  performs the process of aligning the output of each symbol-byte converter  612  and  614  within the block in accordance with a set standard. Herein, the block formatter  620  operates in association with the trellis encoding module  256 . 
         [0165]    More specifically, the block formatter  620  decides the output order of the mobile service data outputted from each symbol-byte converter  612  and  614  while taking into consideration the place (or order) of the data excluding the mobile service data that are being inputted, wherein the mobile service data include main service data, known data, RS parity data, and MPEG header data. 
         [0166]    According to the embodiment of the present invention, the trellis encoding module  256  is provided with 12 trellis encoders.  FIG. 14  illustrates a block diagram showing the trellis encoding module  256  according to the present invention. In the example shown in  FIG. 14 , 12 identical trellis encoders are combined to the interleaver in order to disperse noise. Herein, each trellis encoder may be provided with a pre-coder. 
         [0167]      FIG. 15A  illustrates the block processor  303  being concatenated with the trellis encoding module  256 . In the transmitting system, a plurality of blocks actually exists between the pre-processor  230  including the block processor  303  and the trellis encoding module  256 , as shown in  FIG. 3 . Conversely, the receiving system considers the pre-processor  230  to be concatenated with the trellis encoding module  256 , thereby performing the decoding process accordingly. However, the data excluding the mobile service data that are being inputted to the trellis encoding module  256 , wherein the mobile service data include main service data, known data, RS parity data, and MPEG header data, correspond to data that are added to the blocks existing between the block processor  303  and the trellis encoding module  256 .  FIG. 15B  illustrates an example of a data processor  650  being positioned between the block processor  303  and the trellis encoding module  256 , while taking the above-described instance into consideration. 
         [0168]    Herein, when the interleaving unit  610  of the block processor  303  performs a ½-rate encoding process, the interleaving unit  610  may be configured as shown in  FIG. 12A  (or  FIG. 12B ). Referring to  FIG. 3 , for example, the data processor  650  may include a group formatter  304 , a data deinterleaver  305 , a packet formatter  306 , a packet multiplexer  240 , and a post-processor  250 , wherein the post-processor  250  includes a data randomizer  251 , a RS encoder/non-systematic RS encoder  252 , a data interleaver  253 , a parity replacer  254 , and a non-systematic RS encoder  255 . 
         [0169]    At this point, the trellis encoding module  256  symbolizes the data that are being inputted so as to divide the symbolized data and to send the divided data to each trellis encoder in accordance with a pre-defined method. Herein, one byte is converted into 4 symbols, each being configured of 2 bits. Also, the symbols created from the single data byte are all transmitted to the same trellis encoder. Accordingly, each trellis encoder pre-codes an upper bit of the input symbol, which is then outputted as the uppermost output bit C 2 . Alternatively, each trellis encoder trellis-encodes a lower bit of the input symbol, which is then outputted as two output bits C 1  and C 0 . The block formatter  620  is controlled so that the data byte outputted from each symbol-byte converter can be transmitted to different trellis encoders. 
         [0170]    Hereinafter, the operation of the block formatter  620  will now be described in detail with reference to  FIG. 9  to  FIG. 12 . Referring to  FIG. 12A , for example, the data byte outputted from the symbol-byte converter  612  and the data byte outputted from the symbol-byte converter  614  are inputted to different trellis encoders of the trellis encoding module  256  in accordance with the control of the block formatter  620 . Hereinafter, the data byte outputted from the symbol-byte converter  612  will be referred to as X, and the data byte outputted from the symbol-byte converter  614  will be referred to as Y, for simplicity. Referring to  FIG. 13(   a ), each number (i.e., 0 to 11) indicates the first to twelfth trellis encoders of the trellis encoding module  256 , respectively. 
         [0171]    In addition, the output order of both symbol-byte converters are arranged (or aligned) so that the data bytes outputted from the symbol-byte converter  612  are respectively inputted to the 0 th  to 5 th  trellis encoders ( 0  to  5 ) of the trellis encoding module  256 , and that the data bytes outputted from the symbol-byte converter  614  are respectively inputted to the 6 th  to 11 th  trellis encoders ( 6  to  11 ) of the trellis encoding module  256 . Herein, the trellis encoders having the data bytes outputted from the symbol-byte converter  612  allocated therein, and the trellis encoders having the data bytes outputted from the symbol-byte converter  614  allocated therein are merely examples given to simplify the understanding of the present invention. Furthermore, according to an embodiment of the present invention, and assuming that the input data of the block processor  303  correspond to a block configured of 12 bytes, the symbol-byte converter  612  outputs 12 data bytes from X 0  to X 11 , and the symbol-byte converter  614  outputs 12 data bytes from Y 0  to Y 11 . 
         [0172]      FIG. 13(   b ) illustrates an example of data being inputted to the trellis encoding module  256 . Particularly,  FIG. 13(   b ) illustrates an example of not only the mobile service data but also the main service data and RS parity data being inputted to the trellis encoding module  256 , so as to be distributed to each trellis encoder. More specifically, the mobile service data outputted from the block processor  303  pass through the group formatter  304 , from which the mobile service data are mixed with the main service data and RS parity data and then outputted, as shown in  FIG. 13(   a ). Accordingly, each data byte is respectively inputted to the 12 trellis encoders in accordance with the positions (or places) within the data group after being data-interleaved. 
         [0173]    Herein, when the output data bytes X and Y of the symbol-byte converters  612  and  614  are allocated to each respective trellis encoder, the input of each trellis encoder may be configured as shown in  FIG. 13(   b ). More specifically, referring to  FIG. 13(   b ), the six mobile service data bytes (X 0  to X 5 ) outputted from the symbol-byte converter  612  are sequentially allocated (or distributed) to the first to sixth trellis encoders ( 0  to  5 ) of the trellis encoding module  256 . Also, the 2 mobile service data bytes Y 0  and Y 1  outputted from the symbol-byte converter  614  are sequentially allocated to the 7 th  and 8 th  trellis encoders ( 6  and  7 ) of the trellis encoding module  256 . Thereafter, among the 5 main service data bytes, 4 data bytes are sequentially allocated to the 9 th  and 12 th  trellis encoders ( 8  to  11 ) of the trellis encoding module  256 . Finally, the remaining 1 byte of the main service data byte is allocated once again to the first trellis encoder ( 0 ). 
         [0174]    It is assumed that the mobile service data, the main service data, and the RS parity data are allocated to each trellis encoder, as shown in  FIG. 13(   b ). It is also assumed that, as described above, the input of the block processor  303  is configured of 12 bytes, and that 12 bytes from X 0  to X 11  are outputted from the symbol-byte converter  612 , and that 12 bytes from Y 0  to Y 11  are outputted from the symbol-byte converter  614 . In this case, as shown in FIG.  13 ( c ), the block formatter  620  arranges the data bytes that are to be outputted from the symbol-byte converters  612  and  614  by the order of X 0  to X 5 , Y 0 , Y 1 , X 6  to X 10 , Y 2  to Y 7 , X 11 , and Y 8  to Y 11 . More specifically, the trellis encoder that is to perform the encoding process is decided based upon the position (or place) within the transmission frame in which each data byte is inserted. At this point, not only the mobile service data but also the main service data, the MPEG header data, and the RS parity data are also inputted to the trellis encoding module  256 . Herein, it is assumed that, in order to perform the above-described operation, the block formatter  620  is informed of (or knows) the information on the data group format after the data-interleaving process. 
         [0175]      FIG. 16  illustrates a block diagram of the block processor performing an encoding process at a coding rate of 1/N according to an embodiment of the present invention. Herein, the block processor includes (N−1) number of symbol interleavers  741  to  74 N−1, which are configured in a parallel structure. More specifically, the block processor having the coding rate of 1/N consists of a total of N number of branches (or paths) including a branch (or path), which is directly transmitted to the block formatter  730 . In addition, the symbol interleaver  741  to  74 N−1 of each branch may each be configured of a different symbol interleaver. Furthermore, (N−1) number of symbol-byte converter  751  to  75 N−1 each corresponding to each (N−1) number of symbol interleavers  741  to  74 N−1 may be included at the end of each symbol interleaver, respectively. Herein, the output data of the (N−1) number of symbol-byte converter  751  to  75 N−1 are also inputted to the block formatter  730 . 
         [0176]    In the example of the present invention, N is equal to or smaller than 12. If N is equal to 12, the block formatter  730  may align the output data so that the output byte of the 12 th  symbol-byte converter  75 N−1 is inputted to the 12 th  trellis encoder. Alternatively, if N is equal to 3, the block formatter  730  may arranged the output order, so that the data bytes outputted from the symbol-byte converter  720  are inputted to the 1 st  to 4 th  trellis encoders of the trellis encoding module  256 , and that the data bytes outputted from the symbol-byte converter  751  are inputted to the 5 th  to 8 th  trellis encoders, and that the data bytes outputted from the symbol-byte converter  752  are inputted to the 9 th  to 12 th  trellis encoders. At this point, the order of the data bytes outputted from each symbol-byte converter may vary in accordance with the position within the data group of the data other than the mobile service data, which are mixed with the mobile service data that are outputted from each symbol-byte converter. 
         [0177]      FIG. 17  illustrates a detailed block diagram showing the structure of a block processor according to another embodiment of the present invention. Herein, the block formatter is removed from the block processor so that the operation of the block formatter may be performed by a group formatter. More specifically, the block processor of  FIG. 17  may include a byte-symbol converter  810 , symbol-byte converters  820  and  840 , and a symbol interleaver  830 . In this case, the output of each symbol-byte converter  820  and  840  is inputted to the group formatter  850 . 
         [0178]    Also, the block processor may obtain a desired coding rate by adding symbol interleavers and symbol-byte converters. If the system designer wishes a coding rate of 1/N, the block processor needs to be provided with a total of N number of branches (or paths) including a branch (or path), which is directly transmitted to the block formatter  850 , and (N−1) number of symbol interleavers and symbol-byte converters configured in a parallel structure with (N−1) number of branches. At this point, the group formatter  850  inserts place holders ensuring the positions (or places) for the MPEG header, the non-systematic RS parity, and the main service data. And, at the same time, the group formatter  850  positions the data bytes outputted from each branch of the block processor. 
         [0179]    The number of trellis encoders, the number of symbol-byte converters, and the number of symbol interleavers proposed in the present invention are merely exemplary. And, therefore, the corresponding numbers do not limit the spirit or scope of the present invention. It is apparent to those skilled in the art that the type and position of each data byte being allocated to each trellis encoder of the trellis encoding module  256  may vary in accordance with the data group format. Therefore, the present invention should not be understood merely by the examples given in the description set forth herein. The mobile service data that are encoded at a coding rate of 1/N and outputted from the block processor  303  are inputted to the group formatter  304 . Herein, in the example of the present invention, the order of the output data outputted from the block formatter of the block processor  303  are aligned and outputted in accordance with the position of the data bytes within the data group. 
       Signaling Information Processing 
       [0180]    The transmitter  200  according to the present invention may insert transmission parameters by using a plurality of methods and in a plurality of positions (or places), which are then transmitted to the receiving system. For simplicity, the definition of a transmission parameter that is to be transmitted from the transmitter to the receiving system will now be described. The transmission parameter includes data group information, region information within a data group, the number of RS frames configuring a super frame (i.e., a super frame size (SFS)), the number of RS parity data bytes (P) for each column within the RS frame, whether or not a checksum, which is added to determine the presence of an error in a row direction within the RS frame, has been used, the type and size of the checksum if the checksum is used (presently, 2 bytes are added to the CRC), the number of data groups configuring one RS frame—since the RS frame is transmitted to one burst section, the number of data groups configuring the one RS frame is identical to the number of data groups within one burst (i.e., burst size (BS)), a turbo code mode, and a RS code mode. 
         [0181]    Also, the transmission parameter required for receiving a burst includes a burst period—herein, one burst period corresponds to a value obtained by counting the number of fields starting from the beginning of a current burst until the beginning of a next burst, a positioning order of the RS frames that are currently being transmitted within a super frame (i.e., a permuted frame index (PFI)) or a positioning order of groups that are currently being transmitted within a RS frame (burst) (i.e., a group index (GI)), and a burst size. Depending upon the method of managing a burst, the transmission parameter also includes the number of fields remaining until the beginning of the next burst (i.e., time to next burst (TNB)). And, by transmitting such information as the transmission parameter, each data group being transmitted to the receiving system may indicate a relative distance (or number of fields) between a current position and the beginning of a next burst. 
         [0182]    The information included in the transmission parameter corresponds to examples given to facilitate the understanding of the present invention. Therefore, the proposed examples do not limit the scope or spirit of the present invention and may be easily varied or modified by anyone skilled in the art. According to the first embodiment of the present invention, the transmission parameter may be inserted by allocating a predetermined region of the mobile service data packet or the data group. In this case, the receiving system performs synchronization and equalization on a received signal, which is then decoded by symbol units. Thereafter, the packet deformatter may separate the mobile service data and the transmission parameter so as to detect the transmission parameter. According to the first embodiment, the transmission parameter may be inserted from the group formatter  304  and then transmitted. 
         [0183]    According to the second embodiment of the present invention, the transmission parameter may be multiplexed with another type of data. For example, when known data are multiplexed with the mobile service data, a transmission parameter may be inserted, instead of the known data, in a place (or position) where a known data byte is to be inserted. Alternatively, the transmission parameter may be mixed with the known data and then inserted in the place where the known data byte is to be inserted. According to the second embodiment, the transmission parameter may be inserted from the group formatter  304  or from the packet formatter  306  and then transmitted. 
         [0184]    According to a third embodiment of the present invention, the transmission parameter may be inserted by allocating a portion of a reserved region within a field synchronization segment of a transmission frame. In this case, since the receiving system may perform decoding on a receiving signal by symbol units before detecting the transmission parameter, the transmission parameter having information on the processing methods of the block processor  303  and the group formatter  304  may be inserted in a reserved field of a field synchronization signal. More specifically, the receiving system obtains field synchronization by using a field synchronization segment so as to detect the transmission parameter from a pre-decided position. According to the third embodiment, the transmission parameter may be inserted from the synchronization multiplexer  240  and then transmitted. 
         [0185]    According to the fourth embodiment of the present invention, the transmission parameter may be inserted in a layer (or hierarchical region) higher than a transport stream (TS) packet. In this case, the receiving system should be able to receive a signal and process the received signal to a layer higher than the TS packet in advance. At this point, the transmission parameter may be used to certify the transmission parameter of a currently received signal and to provide the transmission parameter of a signal that is to be received in a later process. 
         [0186]    In the present invention, the variety of transmission parameters associated with the transmission signal may be inserted and transmitted by using the above-described methods according to the first to fourth embodiment of the present invention. At this point, the transmission parameter may be inserted and transmitted by using only one of the four embodiments described above, or by using a selection of the above-described embodiments, or by using all of the above-described embodiments. Furthermore, the information included in the transmission parameter may be duplicated and inserted in each embodiment. Alternatively, only the required information may be inserted in the corresponding position of the corresponding embodiment and then transmitted. Furthermore, in order to ensure robustness of the transmission parameter, a block encoding process of a short cycle (or period) may be performed on the transmission parameter and, then, inserted in a corresponding region. The method for performing a short-period block encoding process on the transmission parameter may include, for example, Kerdock encoding, BCH encoding, RS encoding, and repetition encoding of the transmission parameter. Also, a combination of a plurality of block encoding methods may also be performed on the transmission parameter. 
         [0187]    The transmission parameters may be grouped to create a block code of a small size, so as to be inserted in a byte place allocated within the data group for signaling and then transmitted. However, in this case, the block code passes through the block decoded from the receiving end so as to obtain a transmission parameter value. Therefore, the transmission parameters of the turbo code mode and the RS code mode, which are required for block decoding, should first be obtained. Accordingly, the transmission parameters associated with a particular mode may be inserted in a specific section of a known data region. And, in this case, a correlation of with a symbol may be used for a faster decoding process. The receiving system refers to the correlation between each sequence and the currently received sequences, thereby determining the encoding mode and the combination mode. 
         [0188]    Meanwhile, when the transmission parameter is inserted in the field synchronization segment region or the known data region and then transmitted, and when the transmission parameter has passed through the transmission channel, the reliability of the transmission parameter is deteriorated. Therefore, one of a plurality of pre-defined patterns may also be inserted in accordance with the corresponding transmission parameter. Herein, the receiving system performs a correlation calculation between the received signal and the pre-defined patterns so as to recognize the transmission parameter. For example, it is assumed that a burst including 5 data groups is pre-decided as pattern A based upon an agreement between the transmitting system and the receiving system. In this case, the transmitting system inserts and transmits pattern A, when the number of groups within the burst is equal to 5. Thereafter, the receiving system calculates a correlation between the received data and a plurality of reference patterns including pattern A, which was created in advance. At this point, if the correlation value between the received data and pattern A is the greatest, the received data indicates the corresponding parameter, and most particularly, the number of groups within the burst. At this point, the number of groups may be acknowledged as 5. Hereinafter, the process of inserting and transmitting the transmission parameter will now be described according to first, second, and third embodiments of the present invention. 
       First Embodiment 
       [0189]      FIG. 18  illustrates a schematic diagram of the group formatter  304  receiving the transmission parameter and inserting the received transmission parameter in region A of the data group according to the present invention. Herein, the group formatter  304  receives mobile service data from the block processor  303 . Conversely, the transmission parameter is processed with at least one of a data randomizing process, a RS frame encoding process, and a block processing process, and may then be inputted to the group formatter  304 . Alternatively, the transmission parameter may be directly inputted to the group formatter  304  without being processed with any of the above-mentioned processes. In addition, the transmission parameter may be provided from the service multiplexer  100 . Alternatively, the transmission parameter may also be generated and provided from within the transmitter  200 . The transmission parameter may also include information required by the receiving system in order to receive and process the data included in the data group. For example, the transmission parameter may include data group information, and multiplexing information. 
         [0190]    The group formatter  304  inserts the mobile service data and transmission parameter which are to be inputted to corresponding regions within the data group in accordance with a rule for configuring a data group. For example, the transmission parameter passes through a block encoding process of a short period and is, then, inserted in region A of the data group. Particularly, the transmission parameter may be inserted in a pre-arranged and arbitrary position (or place) within region A. If it is assumed that the transmission parameter has been block encoded by the block processor  303 , the block processor  303  performs the same data processing operation as the mobile service data, more specifically, either a ½-rate encoding or ¼-rate encoding process on the signaling information including the transmission parameter. Thereafter, the block processor  303  outputs the processed transmission parameter to the group formatter  304 . Thereafter, the signaling information is also recognized as the mobile service data and processed accordingly. 
         [0191]      FIG. 19  illustrates a block diagram showing an example of the block processor receiving the transmission parameter and processing the received transmission parameter with the same process as the mobile service data. Particularly,  FIG. 19  illustrates an example showing the structure of  FIG. 9  further including a signaling information provider  411  and multiplexer  412 . More specifically, the signaling information provider  411  outputs the signaling information including the transmission parameter to the multiplexer  412 . The multiplexer  412  multiplexes the signaling information and the output of the RS frame encoder  302 . Then, the multiplexer  412  outputs the multiplexed data to the byte-bit converter  401 . 
         [0192]    The byte-bit converter  401  divides the mobile service data bytes or signaling information byte outputted from the multiplexer  412  into bits, which are then outputted to the symbol encoder  402 . The subsequent operations are identical to those described in  FIG. 9 . Therefore, a detailed description of the same will be omitted for simplicity. If any of the detailed structures of the block processor  303  shown in  FIG. 12 ,  FIG. 15 ,  FIG. 16 , and  FIG. 17 , the signaling information provider  411  and the multiplexer  412  may be provided behind the byte-symbol converter. 
       Second Embodiment 
       [0193]    Meanwhile, when known data generated from the group formatter in accordance with a pre-decided rule are inserted in a corresponding region within the data group, a transmission parameter may be inserted in at least a portion of a region, where known data may be inserted, instead of the known data. For example, when a long known data sequence is inserted at the beginning of region A within the data group, a transmission parameter may be inserted in at least a portion of the beginning of region A instead of the known data. A portion of the known data sequence that is inserted in the remaining portion of region A, excluding the portion in which the transmission parameter is inserted, may be used to detect a starting point of the data group by the receiving system. Alternatively, another portion of region A may be used for channel equalization by the receiving system. 
         [0194]    In addition, when the transmission parameter is inserted in the known data region instead of the actual known data. The transmission parameter may be block encoded in short periods and then inserted. Also, as described above, the transmission parameter may also be inserted based upon a pre-defined pattern in accordance with the transmission parameter. If the group formatter  304  inserts known data place holders in a region within the data group, wherein known data may be inserted, instead of the actual known data, the transmission parameter may be inserted by the packet formatter  306 . More specifically, when the group formatter  304  inserts the known data place holders, the packet formatter  306  may insert the known data instead of the known data place holders. Alternatively, when the group formatter  304  inserts the known data, the known data may be directly outputted without modification. 
         [0195]      FIG. 20  illustrates a block diagram showing the structure of a packet formatter  306  being expanded so that the packet formatter  306  can insert the transmission parameter according to an embodiment of the present invention. More specifically, the structure of the packet formatter  306  further includes a known data generator  351  and a signaling multiplexer  352 . Herein, the transmission parameter that is inputted to the signaling multiplexer  352  may include information on the length of a current burst, information indicating a starting point of a next burst, positions in which the groups within the burst exist and the lengths of the groups, information on the time from the current group and the next group within the burst, and information on known data. 
         [0196]    The signaling multiplexer  352  selects one of the transmission parameter and the known data generated from the known data generator  351  and, then, outputs the selected data to the packet formatter  306 . The packet formatter  306  inserts the known data or transmission parameter outputted from the signaling multiplexer  352  into the known data place holders outputted from the data interleaver  305 . Then, the packet formatter  306  outputs the processed data. More specifically, the packet formatter  306  inserts a transmission parameter in at least a portion of the known data region instead of the known data, which is then outputted. For example, when a known data place holder is inserted at a beginning portion of region A within the data group, a transmission parameter may be inserted in a portion of the known data place holder instead of the actual known data. 
         [0197]    Also, when the transmission parameter is inserted in the known data place holder instead of the known data, the transmission parameter may be block encoded in short periods and inserted. Alternatively, a pre-defined pattern may be inserted in accordance with the transmission parameter. More specifically, the signaling multiplexer  352  multiplexes the known data and the transmission parameter (or the pattern defined by the transmission parameter) so as to configure a new known data sequence. Then, the signaling multiplexer  352  outputs the newly configured known data sequence to the packet formatter  306 . The packet formatter  306  deletes the main service data place holder and RS parity place holder from the output of the data interleaver  305 , and creates a mobile service data packet of 188 bytes by using the mobile service data, MPEG header, and the output of the signaling multiplexer. Then, the packet formatter  306  outputs the newly created mobile service data packet to the packet multiplexer  240 . 
         [0198]    In this case, the region A of each data group has a different known data pattern. Therefore, the receiving system separates only the symbol in a pre-arranged section of the known data sequence and recognizes the separated symbol as the transmission parameter. Herein, depending upon the design of the transmitting system, the known data may be inserted in different blocks, such as the packet formatter  306 , the group formatter  304 , or the block processor  303 . Therefore, a transmission parameter may be inserted instead of the known data in the block wherein the known data are to be inserted. 
         [0199]    According to the second embodiment of the present invention, a transmission parameter including information on the processing method of the block processor  303  may be inserted in a portion of the known data region and then transmitted. In this case, a symbol processing method and position of the symbol for the actual transmission parameter symbol are already decided. Also, the position of the transmission parameter symbol should be positioned so as to be transmitted or received earlier than any other data symbols that are to be decoded. Accordingly, the receiving system may detect the transmission symbol before the data symbol decoding process, so as to use the detected transmission symbol for the decoding process. 
       Third Embodiment 
       [0200]    Meanwhile, the transmission parameter may also be inserted in the field synchronization segment region and then transmitted.  FIG. 21  illustrates a block diagram showing the synchronization multiplexer being expanded in order to allow the transmission parameter to be inserted in the field synchronization segment region. Herein, a signaling multiplexer  261  is further included in the synchronization multiplexer  260 . The transmission parameter of the general VSB method is configured of 2 fields. More specifically, each field is configured of one field synchronization segment and 312 data segments. Herein, the first 4 symbols of a data segment correspond to the segment synchronization portion, and the first data segment of each field corresponds to the field synchronization portion. 
         [0201]    One synchronization signal is configured to have the length of one data segment. The data segment synchronization pattern exists in the first 4 symbols, which are then followed by pseudo random sequences PN  511 , PN  63 , PN  63 , and PN  63 . The next 24 symbols include information associated with the VSB mode. Additionally, the 24 symbols that include information associated with the VSB mode are followed by the remaining 104 symbols, which are reserved symbols. Herein, the last 12 symbols of a previous segment are copied and positioned as the last 12 symbols in the reserved region. In other words, only the 92 symbols in the field synchronization segment are the symbols that correspond to the actual reserved region. 
         [0202]    Therefore, the signaling multiplexer  261  multiplexes the transmission parameter with an already-existing field synchronization segment symbol, so that the transmission parameter can be inserted in the reserved region of the field synchronization segment. Then, the signaling multiplexer  261  outputs the multiplexed transmission parameter to the synchronization multiplexer  260 . The synchronization multiplexer  260  multiplexes the segment synchronization symbol, the data symbols, and the new field synchronization segment outputted from the signaling multiplexer  261 , thereby configuring a new transmission frame. The transmission frame including the field synchronization segment, wherein the transmission parameter is inserted, is outputted to the transmission unit  270 . At this point, the reserved region within the field synchronization segment for inserting the transmission parameter may correspond to a portion of or the entire 92 symbols of the reserved region. Herein, the transmission parameter being inserted in the reserved region may, for example, include information identifying the transmission parameter as the main service data, the mobile service data, or a different type of mobile service data. 
         [0203]    If the information on the processing method of the block processor  303  is transmitted as a portion of the transmission parameter, and when the receiving system wishes to perform a decoding process corresponding to the block processor  303 , the receiving system should be informed of such information on the block processing method in order to perform the decoding process. Therefore, the information on the processing method of the block processor  303  should already be known prior to the block decoding process. Accordingly, as described in the third embodiment of the present invention, when the transmission parameter having the information on the processing method of the block processor  303  (and/or the group formatter  304 ) is inserted in the reserved region of the field synchronization signal and then transmitted, the receiving system is capable of detecting the transmission parameter prior to performing the block decoding process on the received signal. 
       Receiving System 
       [0204]      FIG. 22  is a block diagram illustrating a mobile service data receiving apparatus for processing mobile service data and electronic program information upon receiving mobile service data packet. 
         [0205]    Referring to  FIG. 22 , broadcast receiver  900  for receiving mobile service data according to an embodiment of the present invention includes a signal receiving unit  910 , a demodulating unit  920 , a demultiplexer  940 , a data decoder  950 , a PSI/PSIP database  960 , an A/V decoder  970 , a controller (also called an application &amp; UI manager)  980 , a channel manager  982 , a channel map  984 , a flash memory  986 , a user interface unit  988 , a display unit  990 , a storage unit  1000 , a peripheral-device connection interface unit  1100 , and a thumbnail decoder  1200 , etc. In this case, according to an embodiment of the present invention, the data decoder  950  may be a PSI/PSIP decoder, so that the PSI/PSIP decoder will hereinafter be used instead of the data decoder for the convenience of description and better understanding of the present invention. 
         [0206]    For example, the above-mentioned broadcast receiver  900  may be a digital television (DTV) capable of receiving digital broadcast data, a mobile digital broadcast receiver, etc. 
         [0207]    The signal receiving unit  910  receives a frequency of a specific channel, and outputs it. 
         [0208]    The signal receiving unit  910  can receive mobile service data packet and main service data packet. In other words, the signal receiving unit  910  can selectively receive multiplexed main service data packet and multiplexed mobile service data packet. In this case, the aforementioned selective reception is as follows. For example, if it is assumed that the mobile service data packet and the main service data packet are multiplexed in a burst structure including a burst-on section and a burst-off section, and are then transmitted, the signal receiving unit  910  receives the mobile service data packet during the burst-on section. In this case, the burst-on section may include not only the mobile service data packet but also some parts of the main service data packet. 
         [0209]    In other words, only the main service data packet may be transmitted during the burst-off section, and both the mobile service data packet and the main service data packet may be transmitted during the burst-on section. Thereafter, the signal receiving unit  910  divides the received data of the burst-on section into mobile service data packet and main service data packet. 
         [0210]    In this case, the received broadcast signal includes a Program and System Information/Program and System Information Protocol (PSI/PSIP) table. 
         [0211]    Specifically, the PSI/PSI table includes an Event Information Table (EIT) and a Virtual Channel Table (VCT). 
         [0212]    In the meantime, the signal receiving unit  910  may be controlled by the channel manager  982 . 
         [0213]    The signal receiving unit  910  records the result of the received digital broadcast signal in the channel manager  982 . 
         [0214]    The demodulating unit  920  demodulates the reception (Rx) signal of the signal receiving unit  910 , and divides the Rx signal into mobile service data packet and main service data packet. The demodulating unit  920  performs inverse processing of the transmission end&#39;s process which has been executed to improve a Rx performance of mobile service data. The signal processing of the demodulating unit  920  will be described later with reference to  FIG. 23 . 
         [0215]    The demultiplexer  940  receives the demodulated signal from the demodulating unit  920 , and performs demultiplexing on the received signal, so that it outputs main service data, PSI/PSIP table data associated with the main service data, mobile service data, and PSI/PSIP table data with the mobile service data. The mobile service data and associated PSI/PSIP table data will hereinafter be described using the mobile broadcast receiver as an example. 
         [0216]    The demultiplexing of mobile audio data and mobile video data from among mobile service data may be controlled by the channel manager  982 . The demultiplexing of the PSI/PSIP table may be controlled by the PSI/PSIP decoder  950 . 
         [0217]    The demultiplexed PSI/PSIP table is transmitted to the PSI/PSIP decoder  950 . The demultiplexed mobile audio data and the demultiplexed video data are transmitted to the A/V decoder  970 . The A/V decoder  970  includes an audio decoder and a video decoder. The audio decoder decodes the received audio data using an audio decoding algorithm, and the video decoder decodes the received video data using a video decoding algorithm. 
         [0218]    The PSI/PSIP decoder  950  performs parsing the PSI/PSIP section constructing the table, and records electronic program information in the PSI/PSIP database  960 . In this case, the PSI/PSIP decoder may be an example of the data decoder. 
         [0219]    The channel manager  982  transmits a request for receiving a channel-associated information table by referring to the channel map  984 , and receives a response to the request. 
         [0220]    In this case, the PSI/PSIP decoder  950  controls the demultiplexing of the channel-associated information table, and transmits the A/V and data PID list to the channel manager  982 . 
         [0221]    The channel manager  982  directly controls the multiplexer  940  using the above transmitted A/V PID, so that it controls the A/V decoder  970 . 
         [0222]    The controller  980  controls a Graphical User Interface (GUI) for displaying status information of the above receiving system on the OSD (On Screen Display). 
         [0223]    Particularly, according to the present invention, the demultiplexer  940  demultiplexes the EIT, and transmits the demultiplexed result to the PSI/PSIP decoder  950 . 
         [0224]    The above-mentioned process for decoding the electronic program information from a table including program information can be readily understood, and a detailed description thereof will hereinafter be described with reference to  FIG. 25 . The table including the program information will hereinafter be described using the EIT as an example. 
         [0225]    The PSI/PSIP decoder  950  detects the EIT and acquires information of mobile service data and program information of the inventive mobile service data. 
         [0226]    For example, if the broadcast receiver  900  receives an EPG service request from a user, the channel manager  982  gains access to the PSI/PSIP decoder  950 , and receives information associated with the request. 
         [0227]    The controller  980  controls the display unit  990 , and transmits mobile service data and electronic program information associated with the mobile service data. For example, the electronic program information may be an Electronic Program Guide (EPG). In other words, the controller  980  collects the electronic program information, and controls the EPG information applied to the display unit  990  using the collected electronic program information. 
         [0228]    The controller  980  controls all parts of the storing/reproducing of the received mobile service data. If a storage selection signal is entered, the controller  980  stores data or signals in the storage unit  1000  of the receiver, or stores the data or signals in an external storage unit connected to a peripheral-device connection interface unit  1100 . 
         [0229]    If a playback selection signal is entered, the controller  980  reads mobile service data from the storage unit  1000  of the receiver  900  or the external storage unit connected to the peripheral-device connection interface unit  1100 , and reproduces the read mobile service data. 
         [0230]    The user interface unit  988  receives a user&#39;s selection signal. For example, the user interface unit  988  may receive an EPG function call signal, or receive a signal for selecting a detailed function from among the EPG display. 
         [0231]    The display unit  990  outputs not only mobile service data but also electronic program information associated with the mobile service data. In this case, the mobile service data and the electronic program information associated with the mobile service data may be displayed separately from each other, or may also be displayed at the same time. 
         [0232]    The storage unit  1000  contained in the receiver stores the received mobile service data or PSI/PSIP information of the mobile service data. As the aforementioned mobile service data, the output data of the demodulating unit  920  may be stored, the output data of the demultiplexer  940  may be stored, or the decoded output of the A/V decoder  970  may be stored. This storage unit  1000  may be selectively present in the receiver. 
         [0233]    The peripheral-device connection interface unit  1100  is a connection path to the external storage unit such that the received mobile service data can be stored in the external storage unit. This peripheral-device connection interface unit  1100  can be selectively present in the receiver. 
         [0234]    The thumbnail image decoder  1200  decodes a thumbnail image in which a specific frame of video data is represented by a small-sized image less than an original size. In this case, the thumbnail image decoder  1200  receives the output data of the A/V decoder  970 , decodes the thumbnail image, and stores the decoded thumbnail image in the storage unit  1000 . The thumbnail image decoder will be described later with reference to  FIG. 50 . 
         [0235]      FIG. 23  is a block diagram illustrating the demodulating unit of  FIG. 22  according to the present invention. 
         [0236]    Referring to  FIG. 23 , the demodulating unit recovers a carrier synchronization, a frame synchronization, and performs a channel equalization using known data, so that it improves a Rx performance. In this case, it should be noted that the known data has been inserted into the mobile service data section by the transmission system, and then the transmission system has transmitted the inserted result. 
         [0237]    The demodulating unit  920  includes a demodulator  921 , an equalizer  922 , a known sequence detector  923 , a block decoder  924 , a data deformatter  925 , a RS-frame decoder  926 , a derandomizer  927 , a data deinterleaver  928 , a RS decoder  929 , a data derandomizer  930 , etc. 
         [0238]    For the convenience of description, the data deformatter  925 , the RS frame decoder  926 , and the derandomizer  927  are hereinafter referred to as a mobile service data processor. The data deinterleaver  928 , the RS decoder  929 , and the data derandomizer  930  are hereinafter referred to as a main service data processor. 
         [0239]    For example, provided that the reception system is a broadcast receiving system capable of outputting only mobile service data other than main service data, the demodulating unit  920  according to the present invention may include only the mobile service data processor (i.e., the data deformatter  925 , the RS frame decoder  926 , and the derandomizer  927 ) other than the main service data processor (i.e., the data deinterleaver  928 , the RS decoder  929 , and the data derandomizer  930 ). 
         [0240]    And, provided that the reception system is a system capable of outputting both the main service data and the mobile service data, the demodulating unit  920  according to the present invention may include both the mobile service data processor (i.e., the data deformatter  925 , the RS frame decoder  926 , and the derandomizer  927 ) and the main service data processor (i.e., the data deinterleaver  928 , the RS decoder  929 , and the data derandomizer  930 ). 
         [0241]    In this case, mobile service data and electronic program information associated with the mobile service data are simultaneously processed by the demodulating unit  920 . 
         [0242]    In more detail, the signal receiving unit  910  receives a frequency of a specific channel, converts the received frequency into an Intermediate Frequency (IF) signal, and outputs the converted result to the demodulator  921  and the known sequence detector  923 . 
         [0243]    The demodulator  921  receives the IF signal from the demodulator  921 , performs an automatic gain control, a carrier recovery, and a timing recovery on the received IF signal to create a baseband signal, and outputs the baseband signal to the equalizer  922  and the known sequence detector  923 . 
         [0244]    The equalizer  922  compensates for channel distortion contained in the demodulated signal, and outputs the compensated result to the block decoder  924 . 
         [0245]    At this point, the known sequence detector  923  detects the known sequence place inserted by the transmitting end from the input/output data of the demodulator  921  (i.e., the data prior to the demodulation process or the data after the demodulation process). Thereafter, the place information along with the symbol sequence of the known data, which are generated from the detected place, is outputted to the demodulator  921  and the equalizer  922 . Also, the known sequence detector  923  outputs a set of information to the block decoder  924 . This set of information is used to allow the block decoder  924  of the receiving system to identify the mobile service data that are processed with additional encoding from the transmitting system and the main service data that are not processed with additional encoding. In addition, although the connection status is not shown in  FIG. 23 , the information detected from the known sequence detector  923  may be used throughout the entire receiving system and may also be used in the data deformatter  925  and the RS frame decoder  926 . The demodulator  921  uses the known data symbol sequence during the timing and/or carrier recovery, thereby enhancing the demodulating performance. Similarly, the equalizer  922  uses the known data so as to enhance the equalizing performance. Moreover, the decoding result of the block decoder  924  may be fed-back to the equalizer  922 , thereby enhancing the equalizing performance. 
         [0246]    The equalizer  922  may perform channel equalization by using a plurality of methods. An example of estimating a channel impulse response (CIR) so as to perform channel equalization will be given in the description of the present invention. Most particularly, an example of estimating the CIR in accordance with each region within the data group, which is hierarchically divided and transmitted from the transmitting system, and applying each CIR differently will also be described herein. Furthermore, by using the known data, the place and contents of which is known in accordance with an agreement between the transmitting system and the receiving system, and the field synchronization data, so as to estimate the CIR, the present invention may be able to perform channel equalization with more stability. 
         [0247]    Herein, the data group that is inputted for the equalization process is divided into regions A to C, as shown in  FIG. 6A . More specifically, in the example of the present invention, each region A, B, and C are further divided into regions A 1  to A 5 , regions B 1  and B 2 , and regions C 1  to C 3 , respectively. Referring to  FIG. 6A , the CIR that is estimated from the field synchronization data in the data structure is referred to as CIR_FS. Alternatively, the CIRs that are estimated from each of the 5 known data sequences existing in region A are sequentially referred to as CIR_N 0 , CIR_N 1 , CIR_N 2 , CIR_N 3 , and CIR_N 4 . 
         [0248]    As described above, the present invention uses the CIR estimated from the field synchronization data and the known data sequences in order to perform channel equalization on data within the data group. At this point, each of the estimated CIRs may be directly used in accordance with the characteristics of each region within the data group. Alternatively, a plurality of the estimated CIRs may also be either interpolated or extrapolated so as to create a new CIR, which is then used for the channel equalization process. 
         [0249]    Herein, when a value F(A) of a function F(x) at a particular point A and a value F(B) of the function F(x) at another particular point B are known, interpolation refers to estimating a function value of a point within the section between points A and B. Linear interpolation corresponds to the simplest form among a wide range of interpolation operations. The linear interpolation described herein is merely exemplary among a wide range of possible interpolation methods. And, therefore, the present invention is not limited only to the examples set forth herein. 
         [0250]    Alternatively, when a value F(A) of a function F(x) at a particular point A and a value F(B) of the function F(x) at another particular point B are known, extrapolation refers to estimating a function value of a point outside of the section between points A and B. Linear extrapolation is the simplest form among a wide range of extrapolation operations. Similarly, the linear extrapolation described herein is merely exemplary among a wide range of possible extrapolation methods. And, therefore, the present invention is not limited only to the examples set forth herein. 
         [0251]    More specifically, in case of region C 1 , any one of the CIR_N 4  estimated from a previous data group, the CIR_FS estimated from the current data group that is to be processed with channel equalization, and a new CIR generated by extrapolating the CIR_FS of the current data group and the CIR_N 0  may be used to perform channel equalization. Alternatively, in case of region B 1 , a variety of methods may be applied as described in the case for region C 1 . For example, a new CIR created by linearly extrapolating the CIR_FS estimated from the current data group and the CIR_N 0  may be used to perform channel equalization. Also, the CIR_FS estimated from the current data group may also be used to perform channel equalization. Finally, in case of region A 1 , a new CIR may be created by interpolating the CIR_FS estimated from the current data group and CIR_N 0 , which is then used to perform channel equalization. Furthermore, any one of the CIR_FS estimated from the current data group and CIR_N 0  may be used to perform channel equalization. 
         [0252]    In case of regions A 2  to A 5 , CIR_N(i−1) estimated from the current data group and CIR_N(i) may be interpolated to create a new CIR and use the newly created CIR to perform channel equalization. Also, any one of the CIR_N(i−1) estimated from the current data group and the CIR_N(i) may be used to perform channel equalization. Alternatively, in case of regions B 2 , C 2 , and C 3 , CIR_N 3  and CIR_N 4  both estimated from the current data group may be extrapolated to create a new CIR, which is then used to perform the channel equalization process. Furthermore, the CIR_N 4  estimated from the current data group may be used to perform the channel equalization process. Accordingly, an optimum performance may be obtained when performing channel equalization on the data inserted in the data group. The methods of obtaining the CIRs required for performing the channel equalization process in each region within the data group, as described above, are merely examples given to facilitate the understanding of the present invention. A wider range of methods may also be used herein. And, therefore, the present invention will not only be limited to the examples given in the description set forth herein. 
         [0253]    Meanwhile, if the data being inputted to the block decoder  924  after being channel equalized from the equalizer  922  correspond to the mobile service data having additional encoding and trellis encoding performed thereon by the transmitting system, trellis decoding and additional decoding processes are performed on the inputted data as inverse processes of the transmitting system. Alternatively, if the data being inputted to the block decoder  924  correspond to the main service data having only trellis encoding performed thereon, and not the additional encoding, only the trellis decoding process is performed on the inputted data as the inverse process of the transmitting system. 
         [0254]    The data group decoded by the block decoder  924  is inputted to the data deformatter  925 , and the main service data are inputted to the data deinterleaver  928 . According to another embodiment, the main data may also bypass the block decoder  924  so as to be directly inputted to the data deinterleaver  928 . In this case, a trellis decoder for the main service data should be provided before the data deinterleaver  928 . When the block decoder  924  outputs the data group to the data deformatter  925 , the known data, trellis initialization data, and MPEG header, which are inserted in the data group, and the RS parity, which is added by the RS encoder/non-systematic RS encoder or non-systematic RS encoder of the transmitting system, are removed. Then, the processed data are outputted to the data deformatter  925 . Herein, the removal of the data may be performed before the block decoding process, or may be performed during or after the block decoding process. If the transmitting system includes signaling information in the data group upon transmission, the signaling information is outputted to the data deformatter  925 . 
         [0255]    More specifically, if the inputted data correspond to the main service data, the block decoder  924  performs Viterbi decoding on the inputted data so as to output a hard decision value or to perform a hard-decision on a soft decision value, thereby outputting the result. Meanwhile, if the inputted data correspond to the mobile service data, the block decoder  924  outputs a hard decision value or a soft decision value with respect to the inputted mobile service data. In other words, if the inputted data correspond to the mobile service data, the block decoder  924  performs a decoding process on the data encoded by the block processor and trellis encoding module of the transmitting system. 
         [0256]    At this point, the RS frame encoder of the pre-processor included in the transmitting system may be viewed as an external code. And, the block processor and the trellis encoder may be viewed as an internal code. In order to maximize the performance of the external code when decoding such concatenated codes, the decoder of the internal code should output a soft decision value. Therefore, the block decoder  924  may output a hard decision value on the mobile service data. However, when required, it may be more preferable for the block decoder  924  to output a soft decision value. 
         [0257]    Meanwhile, the data deinterleaver  928 , the RS decoder  929 , and the derandomizer  930  are blocks required for receiving the main service data. Therefore, the above-mentioned blocks may not be required in the structure of a receiving system that only receives the mobile service data. The data deinterleaver  928  performs an inverse process of the data interleaver included in the transmitting system. In other words, the data deinterleaver  928  deinterleaves the main service data outputted from the block decoder  924  and outputs the deinterleaved main service data to the RS decoder  929 . The RS decoder  929  performs a systematic RS decoding process on the deinterleaved data and outputs the processed data to the derandomizer  930 . The derandomizer  930  receives the output of the RS decoder  929  and generates a pseudo random data byte identical to that of the randomizer included in the transmitting system. Thereafter, the derandomizer  930  performs a bitwise exclusive OR (XOR) operation on the generated pseudo random data byte, thereby inserting the MPEG synchronization bytes to the beginning of each packet so as to output the data in 188-byte main service data packet units. 
         [0258]    Meanwhile, the data being outputted from the block decoder  924  to the data deformatter  925  are inputted in the form of a data group. At this point, the data deformatter  925  already knows the structure of the data that are to be inputted and is, therefore, capable of identifying the signaling information, which includes the system information, and the mobile service data from the data group. Thereafter, the data deformatter  925  outputs the identified signaling information to a block for processing signaling information (not shown) and outputs the identified mobile service data to the RS frame decoder  926 . More specifically, the RS frame decoder  926  receives only the RS encoded and CRC encoded mobile service data that are transmitted from the data deformatter  925 . 
         [0259]    The RS frame encoder  926  performs an inverse process of the RS frame encoder included in the transmitting system so as to correct the error within the RS frame. Then, the RS frame decoder  926  adds the 1-byte MPEG synchronization service data packet, which had been removed during the RS frame encoding process, to the error-corrected mobile service data packet. Thereafter, the processed data packet is outputted to the derandomizer  927 . The operation of the RS frame decoder  926  will be described in detail in a later process. The derandomizer  927  performs a derandomizing process, which corresponds to the inverse process of the randomizer included in the transmitting system, on the received mobile service data. Thereafter, the derandomized data are outputted, thereby obtaining the mobile service data transmitted from the transmitting system. Hereinafter, detailed operations of the RS frame decoder  926  will now be described. 
         [0260]      FIG. 24  illustrates a series of exemplary step of an error correction decoding process of the RS frame decoder  926  according to the present invention. More specifically, the RS frame decoder  926  groups mobile service data bytes received from the data deformatter  925  so as to configure an RS frame. The mobile service data correspond to data RS encoded and CRC encoded from the transmitting system.  FIG. 24(   a ) illustrates an example of configuring the RS frame. More specifically, the transmitting system divided the RS frame having the size of (N+2)*235 to 30*235 byte blocks. When it is assumed that each of the divided mobile service data byte blocks is inserted in each data group and then transmitted, the receiving system also groups the 30*235 mobile service data byte blocks respectively inserted in each data group, thereby configuring an RS frame having the size of (N+2)*235. For example, when it is assumed that an RS frame is divided into 18 30*235 byte blocks and transmitted from a burst section, the receiving system also groups the mobile service data bytes of 18 data groups within the corresponding burst section, so as to configure the RS frame. Furthermore, when it is assumed that N is equal to 538 (i.e., N=538), the RS frame decoder  926  may group the mobile service data bytes within the 18 data groups included in a burst so as to configure a RS frame having the size of 540*235 bytes. 
         [0261]    Herein, when it is assumed that the block decoder  924  outputs a soft decision value for the decoding result, the RS frame decoder  926  may decide the ‘0’ and ‘1’ of the corresponding bit by using the codes of the soft decision value. 8 bits that are each decided as described above are grouped to create 1 data byte. If the above-described process is performed on all soft decision values of the 18 data groups included in a single burst, the RS frame having the size of 540*235 bytes may be configured. Additionally, the present invention uses the soft decision value not only to configure the RS frame but also to configure a reliability map. Herein, the reliability map indicates the reliability of the corresponding data byte, which is configured by grouping 8 bits, the 8 bits being decided by the codes of the soft decision value. 
         [0262]    For example, when the absolute value of the soft decision value exceeds a pre-determined threshold value, the value of the corresponding bit, which is decided by the code of the corresponding soft decision value, is determined to be reliable. Conversely, when the absolute value of the soft decision value does not exceed the pre-determined threshold value, the value of the corresponding bit is determined to be unreliable. Thereafter, if even a single bit among the 8 bits, which are decided by the codes of the soft decision value and group to configure 1 data byte, is determined to be unreliable, the corresponding data byte is marked on the reliability map as an unreliable data byte. 
         [0263]    Herein, determining the reliability of 1 data byte is only exemplary. More specifically, when a plurality of data bytes (e.g., at least 4 data bytes) are determined to be unreliable, the corresponding data bytes may also be marked as unreliable data bytes within the reliability map. Conversely, when all of the data bits within the 1 data byte are determined to be reliable (i.e., when the absolute value of the soft decision values of all 8 bits included in the 1 data byte exceed the predetermined threshold value), the corresponding data byte is marked to be a reliable data byte on the reliability map. Similarly, when a plurality of data bytes (e.g., at least 4 data bytes) are determined to be reliable, the corresponding data bytes may also be marked as reliable data bytes within the reliability map. The numbers proposed in the above-described example are merely exemplary and, therefore, do not limit the scope or spirit of the present invention. 
         [0264]    The process of configuring the RS frame and the process of configuring the reliability map both using the soft decision value may be performed at the same time. Herein, the reliability information within the reliability map is in a one-to-one correspondence with each byte within the RS frame. For example, if a RS frame has the size of 540*235 bytes, the reliability map is also configured to have the size of 540*235 bytes.  FIG. 24(   a ′) illustrates the process steps of configuring the reliability map according to the present invention. Meanwhile, if a RS frame is configured to have the size of (N+2)*235 bytes, the RS frame decoder  926  performs a CRC syndrome checking process on the corresponding RS frame, thereby verifying whether any error has occurred in each row. Subsequently, as shown in  FIG. 24(   b ), a 2-byte checksum is removed to configure an RS frame having the size of N*235 bytes. Herein, the presence (or existence) of an error is indicated on an error flag corresponding to each row. Similarly, since the portion of the reliability map corresponding to the CRC checksum has hardly any applicability, this portion is removed so that only N*235 number of the reliability information bytes remain, as shown in  FIG. 24(   b ′). 
         [0265]    After performing the CRC syndrome checking process, the RS frame decoder  926  performs RS decoding in a column direction. Herein, a RS erasure correction process may be performed in accordance with the number of CRC error flags. More specifically, as shown in  FIG. 24(   c ), the CRC error flag corresponding to each row within the RS frame is verified. Thereafter, the RS frame decoder  926  determines whether the number of rows having a CRC error occurring therein is equal to or smaller than the maximum number of errors on which the RS erasure correction may be performed, when performing the RS decoding process in a column direction. The maximum number of errors corresponds to a number of parity bytes inserted when performing the RS encoding process. In the embodiment of the present invention, it is assumed that 48 parity bytes have been added to each column. 
         [0266]    If the number of rows having the CRC errors occurring therein is smaller than or equal to the maximum number of errors (i.e., 48 errors according to this embodiment) that can be corrected by the RS erasure decoding process, a (235,187)-RS erasure decoding process is performed in a column direction on the RS frame having 235 N-byte rows, as shown in  FIG. 24(   d ). Thereafter, as shown in  FIG. 24(   f ), the 48-byte parity data that have been added at the end of each column are removed. Conversely, however, if the number of rows having the CRC errors occurring therein is greater than the maximum number of errors (i.e., 48 errors) that can be corrected by the RS erasure decoding process, the RS erasure decoding process cannot be performed. In this case, the error may be corrected by performing a general RS decoding process. In addition, the reliability map, which has been created based upon the soft decision value along with the RS frame, may be used to further enhance the error correction ability (or performance) of the present invention. 
         [0267]    More specifically, the RS frame decoder  926  compares the absolute value of the soft decision value of the block decoder  924  with the pre-determined threshold value, so as to determine the reliability of the bit value decided by the code of the corresponding soft decision value. Also, 8 bits, each being determined by the code of the soft decision value, are grouped to form 1 data byte. Accordingly, the reliability information on this 1 data byte is indicated on the reliability map. Therefore, as shown in  FIG. 24(   e ), even though a particular row is determined to have an error occurring therein based upon a CRC syndrome checking process on the particular row, the present invention does not assume that all bytes included in the row have errors occurring therein. The present invention refers to the reliability information of the reliability map and sets only the bytes that have been determined to be unreliable as erroneous bytes. In other words, with disregard to whether or not a CRC error exists within the corresponding row, only the bytes that are determined to be unreliable based upon the reliability map are set as erasure points. 
         [0268]    According to another method, when it is determined that CRC errors are included in the corresponding row, based upon the result of the CRC syndrome checking result, only the bytes that are determined by the reliability map to be unreliable are set as errors. More specifically, only the bytes corresponding to the row that is determined to have errors included therein and being determined to be unreliable based upon the reliability information, are set as the erasure points. Thereafter, if the number of error points for each column is smaller than or equal to the maximum number of errors (i.e., 48 errors) that can be corrected by the RS erasure decoding process, an RS erasure decoding process is performed on the corresponding column. Conversely, if the number of error points for each column is greater than the maximum number of errors (i.e., 48 errors) that can be corrected by the RS erasure decoding process, a general decoding process is performed on the corresponding column. 
         [0269]    More specifically, if the number of rows having CRC errors included therein is greater than the maximum number of errors (i.e., 48 errors) that can be corrected by the RS erasure decoding process, either an RS erasure decoding process or a general RS decoding process is performed on a column that is decided based upon the reliability information of the reliability map, in accordance with the number of erasure points within the corresponding column. For example, it is assumed that the number of rows having CRC errors included therein within the RS frame is greater than 48. And, it is also assumed that the number of erasure points decided based upon the reliability information of the reliability map is indicated as 40 erasure points in the first column and as 50 erasure points in the second column. In this case, a (235,187)-RS erasure decoding process is performed on the first column. Alternatively, a (235,187)-RS decoding process is performed on the second column. When error correction decoding is performed on all column directions within the RS frame by using the above-described process, the 48-byte parity data which were added at the end of each column are removed, as shown in  FIG. 24(   f ). 
         [0270]    As described above, even though the total number of CRC errors corresponding to each row within the RS frame is greater than the maximum number of errors that can be corrected by the RS erasure decoding process, when the number of bytes determined to have a low reliability level, based upon the reliability information on the reliability map within a particular column, while performing error correction decoding on the particular column. Herein, the difference between the general RS decoding process and the RS erasure decoding process is the number of errors that can be corrected. More specifically, when performing the general RS decoding process, the number of errors corresponding to half of the number of parity bytes (i.e., (number of parity bytes)/2) that are inserted during the RS encoding process may be error corrected (e.g., 24 errors may be corrected). Alternatively, when performing the RS erasure decoding process, the number of errors corresponding to the number of parity bytes that are inserted during the RS encoding process may be error corrected (e.g., 48 errors may be corrected). 
         [0271]    After performing the error correction decoding process, as described above, a RS frame configured of 187 N-byte rows (or packets) maybe obtained, as shown in  FIG. 24(   f ). Furthermore, the RS frame having the size of N*187 bytes is sequentially outputted in N number of 187-byte units. Herein, as shown in  FIG. 24(   g ), the 1-byte MPEG synchronization byte that was removed by the transmitting system is added at the end of each 187-byte packet, thereby outputting 188-byte mobile service data packets. 
         [0272]    The term “receiver” in the present invention is indicative of a mobile receiver for receiving/processing mobile service data packet. 
         [0273]    When the mobile receiver processes/provides the mobile service data, a method for automatically establishing channels (hereinafter referred to as an auto-channel setup method) will hereinafter be described. 
         [0274]      FIG. 25  is a flow chart illustrating an automatic channel setup method according to one embodiment of the present invention. 
         [0275]    When the mobile receiver receives/processes/provides mobile service data, it determines whether an auto-channel setup command exists or not. If the auto-channel setup command exists at step S 2510 , the initial scan channel is established according to the auto-channel setup command at step S 2520 . 
         [0276]    In this case, the auto-channel setup command may be entered by a user, or may be generated as a specific event of a receiver. The initial scan channel may be at least one of a preset fixed channel, a channel corresponding to the previous last scan position, a current Rx channel, or a user-requested channel or a setup channel. The scanning for the above-mentioned auto-channel setup may be executed in the range from the initial scan channel to the last channel. Otherwise, the scanning is circulated, and may then be executed until reaching the previous channel located right before the initial scan channel. 
         [0277]    If the initial scan channel is established, the initial scan channel is tuned at step S 2530 . The mobile receiver determines whether data exists in the tuned initial scan channel at step S 2540 . In this case, the aforementioned data determining the presence or absence at step S 2540  is not limited to specific-type data, may include all types of data (including main service data and mobile service data), may include only data including the signal intensity of more than a predetermined level prescribed in the receiver, may include only mobile service data, or may include only displayable data. 
         [0278]    If data exists in the tuned first scan channel at step S 2540 , the receiver stores channel information of the corresponding channel at step S 2550 . In this case, the stored channel information may include information capable of specifying channel, for example, a channel frequency, a channel logo, a channel name, and a channel number. If the stored channel information is service data, it is divided into main service data and mobile service data, so that the main service data and the mobile service data are stored in different spaces. 
         [0279]    After storing the channel information at step S 2550 , the receiver determines whether the end event associated with the auto-channel setup occurs at step S 2560 . If the end event has occurred at step S 2560 , the auto-channel setup process is terminated. Otherwise, if the absence of the end event is decided at step S 2560 , the next scan channel is established, the steps S 2530 ˜S 2560  are repeated, so that the auto-channel setup is performed. 
         [0280]      FIG. 26  is a flow chart illustrating an automatic channel setup method according to another embodiment of the present invention. For example, if a transmission end transmits the list of all channels over a specific channel, the auto-channel setup method of  FIG. 26  is executed. A detailed description of the above-mentioned auto-channel setup method will hereinafter be described with reference to  FIG. 26 . 
         [0281]    A broadcast receiver receives an auto-channel setup command at step S 2610 , and switches a current channel to a predetermined specific channel at step S 2620 . This specific channel may be indicative of a specific PID including frequency- or program-information prescribed between transmission/reception ends. The frequency or the specific PID may include channel information of all channels. And, the number of specific channels may not be limited to only one, and can also be set to other numbers as necessary. 
         [0282]    After performing the channel switching, the broadcast receiver receives channel information over the switched channel at step S 2630 . In this case, the channel information may include a channel frequency, a channel name, a channel number, and a channel icon. 
         [0283]    The broadcast receiver generates the channel list using the received channel information at step S 2640 . In this case, the generated channel list may be configured according to either a format provided from a transmission end or another format prescribed in the broadcast receiver. Also, the broadcast receiver outputs the channel list of the step S 2640 , such that a user can edit the channel list. 
         [0284]    Another example of the auto-channel setup method is as follows. 
         [0285]      FIG. 27  is a flow chart illustrating an automatic channel setup method according to another embodiment of the present invention. For example, if the mobile broadcast receiver has mobile Rx (Reception) characteristic (i.e., if the mobile service data is in motion), instead of fixed Rx characteristics, the auto-channel setup process of  FIG. 27  is performed, and a detailed description thereof will hereinafter be described. 
         [0286]    The broadcast receiver receives position information to recognize its position at step S 2710 . In this case, if the broadcast receiver performs parsing a table associated with position information of a PSI/PSIP associated with mobile services in the mobile service data packet, the received position information may be acquired. Otherwise, the received position information may also be acquired from the position information module contained in the broadcast receiver. If required, the broadcast receiver may directly receive position information from the user. 
         [0287]    The position information module may include at least one of a GPS receiver and an azimuth sensor, or both of them. Generally, the position information module may receive position information via the GPS receiver. At a specific part at which the GPS receiver is disabled, the position information module may use the azimuth sensor. In this case, the azimuth sensor may receive a signal from at least one of an angular sensor, a geomagnetic sensor, and a vehicle-speed sensor, such that it can calculate the vehicle&#39;s position on the basis of the received signal. 
         [0288]    For example, a broadcast receiver for use in the vehicle decodes or extracts correction data using GPS information and various sensors of the vehicle, such that the position of the moving broadcast receiver is corrected by the decoded or extracted correction data, such that the current position of the broadcast receiver can be recognized. 
         [0289]    As described above, the position information module may acquire position information using the above-mentioned two information, and can acquire position information using either only GPS information or only the azimuth sensor. 
         [0290]    The broadcast receiver determines whether it has moved from one region to another region using the received position information at step S 2720 . In more detail, the broadcast receiver matches map- or geographical-information with the position information, so that it can determine whether the information. In this case, it should be noted that the map- or geographical-information is pre-stored or provided from an information center. The map- or geographical-information may be updated by a communication module at intervals of a predetermined time, so that only the latest information is stored as the map- or geographical-information. 
         [0291]    Therefore, for example, if the stored map information is matched with current position of the broadcast receiver such that the matched result is displayed, or if a moving path from a current position to a destination is provided to the user at a path searching mode, the stored map information can be used. 
         [0292]    If the broadcast receiver moves from one region to another region (i.e., a region shift) at step S 2720 , it is determined whether the change of a channel map is required at step S 2730 . 
         [0293]    If the change of the channel map is required due to the region shift at step S 2730 , the channel map is changed at step S 2740 . In this case, in association with the above channel-map change, the auto-channel setup method may be used. For example, the auto-channel setup method may follow the method of  FIG. 25  or  26 . And, provided that a fixed channel map exists in each region, and a fixed channel map is pre-assigned to each region of the broadcast receiver, the broadcast receiver may extract the pre-stored channel map using the region information matched with the received position information, and may change the extract channel map to another map. 
         [0294]      FIG. 28  exemplarily shows the list of channels established by the automatic channel setup method according to the present invention. The channel list of  FIG. 28  may include a channel-information window  2801 , a preview window  2802 , and a mobile/main channel list window  2803 . 
         [0295]    Namely, the broadcast receiver performs the auto-channel setup process using the above-mentioned procedures, and displays the channel list. The user navigates the channel list, such that he or she selects a specific channel. In this case, the broadcast receiver may provide preview information via the preview window  2802  of the user-selected channel, or may provide channel information via the channel-information window  2801 . 
         [0296]    Also, the user can select or edit the channel list. In this case, the editing may include at least one of deleting/adding the channel, establishing a preferred channel, performing a channel-lock setup, or performing a channel-order editing. 
         [0297]    Next, when the broadcast receiver receives and provides the received mobile service data and provides, the following manual-channel setup method is executed, and a detailed description thereof will hereinafter be described with reference to  FIG. 29 . 
         [0298]      FIG. 29  is a conceptual diagram illustrating a manual channel setup method according to the present invention. For example, the manual-channel setup process is activated, when the user enters a command for at least one channel which is not contained in the channel list constructed by the aforementioned auto-channel setup method, so that the channel is manually established. 
         [0299]    As can be seen from  FIG. 29 , in order to establish the manual channel, the broadcast receiver may display an input window  2901 , a channel-information window  2902 , a reception-sensitivity window  2903 , and a channel-storing question window  2904  of at least one of a channel number and a channel type. 
         [0300]    Namely, if the user enters a channel number or/and channel-type information on the input window  2901  in order to perform the manual-channel setup, the broadcast receiver scans a corresponding channel according to the user-entry information. In this case, a channel type may include at least one of a main service and a mobile service. The channel number may be a channel number or channel name of a specific channel. 
         [0301]    The broadcast receiver outputs the scanned specific channel. After outputting the channel, the user may determine whether to store a corresponding channel via the question window  2904 . Therefore, if the user decides to store a corresponding channel on the question window  2904 , a corresponding channel is contained in the channel map. For example, the above-mentioned user selection result may be updated to the above-mentioned channel list. 
         [0302]    The broadcast receiver may provide corresponding channel information on the channel-information window  2902 , or may provide the Rx-sensitivity degree of broadcast data received via a corresponding channel on the Rx-sensitivity window  2903 , so that the user can easily decide whether to store a corresponding channel. 
         [0303]    Next, when the broadcast receiver processes and provides mobile service data, the following input selection method is executed, and a detailed description thereof will hereinafter be described. In this case, the broadcast receiver includes a reception block capable of receiving a broadcast signal from several input sources, and includes a multiplexer capable of multiplexing several broadcast signals. 
         [0304]      FIG. 30  is a block diagram illustrating an apparatus for multiplexing a broadcast signal received from several input sources using a mobile broadcast receiver according to the present invention. For the convenience of description, the above-mentioned apparatus is called a mobile hybrid source signal receiver, and may be contained in the broadcast receiver. 
         [0305]    The mobile hybrid source signal receiver may receive mobile service data from a broadcast network, may receive data from a satellite network, may receive data from a wired/wireless Internet, may receive communication data (e.g., video communication data) from a wired/wireless communication network, may receive position data from a navigation device including a position-information module, or may receive several data units from several input sources (e.g., record/playback data). 
         [0306]    Also, the mobile hybrid source signal receiver may receive broadcast information (i.e., program information) of the mobile service data via the several input sources. In this case, if the mobile hybrid source signal receiver merges the program information received via several input sources, and the merged result is provided via a single program guide, the user can more conveniently select the program. 
         [0307]    Referring to  FIG. 30 , the mobile hybrid source signal receiver according to the present invention includes a source integrated program information generator  3020 . The source integrated program information generator  3020  merges the program information received via at least two source input modules, so that it outputs the integrated source program information. 
         [0308]    The source input module may include a mobile communication module, a mobile service data reception module, an Internet module, and a satellite reception module. Besides, the scope of the source input modules is not limited to only the above-mentioned examples, and can also be applied to other examples as necessary. The mobile hybrid source signal receiver includes several source input modules (i.e., first to n-th source input modules). 
         [0309]    The source integrated program information generator  3020  integrates program information generated from individual source input modules contained in the source input module  3010 , and outputs the integrated source program information. In this case, the source integrated program information generator  3020  assigns identifiers for identifying source types to corresponding program information, such that input sources can be distinguished from each other. Also, the source integrated program information generator  3020  extracts program information, so that source types can be distinguished from each other. 
         [0310]      FIG. 31A  and  FIG. 31B  show user-selection screen images according to the integrated source program information. 
         [0311]      FIG. 31A  shows a screen image for processing/outputting program information transmitted via the source selected by the user in the broadcast receiver. The screen image of  FIG. 31A  includes at least one display window.  FIG. 31B  shows an exemplary user interface (UI), which allows the user to select a source type of the output image of each display window. In this case, as shown in  FIG. 31B , the sources may include at least one of mobile service data, communication data, navigation data, wireless Internet, and record/play data. 
         [0312]    At least one display window of  FIG. 31A  is shown at the left side of  FIG. 31B . Several input sources are shown at the right side of  FIG. 31B , so that the user can select the input source displayed on the left display window. 
         [0313]    For example, the broadcast receiver includes a first display window  3101 , a second display window  3102 , and a third display window  3103  as shown in  FIG. 31A . If the user selects the first display window via the UI of  FIG. 31B  and selects mobile service data as input sources of the first display window, the broadcast receiver processes the mobile service data and outputs the processed result on the first display window  3101 . 
         [0314]    Next, a method for adjusting (compensating/correcting) an image setup value using the broadcast receiver capable of receiving/processing/providing mobile service data will hereinafter be described. 
         [0315]      FIG. 32A  and  FIG. 32B  show examples for adjusting an image setup value according to the present invention. 
         [0316]    Referring to  FIG. 32A , the broadcast receiver determines whether a manual control command for allowing a user to manually adjusting the image setup value is received or not. The manual control command is an image setup value decided by the user. 
         [0317]    Upon receiving the manual control command, the broadcast receiver adjusts (compensates/corrects) a corresponding image according to the user-setup value, and outputs the adjusted result. The image setup item capable of being manually adjusted by the user is at least one of constrast, brightness, color, sharpness, and tint. 
         [0318]      FIG. 32B  shows another example of the manual control method. In more detail,  FIG. 32B  shows the presetting items of image setup items of  FIG. 32A . In this case, the pre-setting items of  FIG. 32B  may include daylight, normal, and night-time. 
         [0319]    Therefore, if the user selects any one of the presetting items of  FIG. 32B , the broadcast receiver selects the image according to the presetting values of the selected items. 
         [0320]    Next, a color-temperature setup method for the broadcast receiver capable of receiving/processing/providing mobile service data will hereinafter be described. 
         [0321]      FIG. 33A  and  FIG. 33B  show methods for adjusting a color temperature according to the present invention. 
         [0322]    The broadcast receiver determines whether a user enters a color-temperature control command during the processing time of the mobile service data. If the color-temperature control command has been entered by the user, the broadcast receiver processes the mobile service data according to the user-selected color-temperature value, and outputs the processed result. 
         [0323]    In this case, items for adjusting the color temperature include red, green, and blue as shown in  FIG. 33A . As shown in  FIG. 33B , the red, the green, or the blue is denoted by a predetermined magnification, for example, Cool (11,000 k), Medium (8,000 k), or Warm (6,500 k). 
         [0324]    If the user selects any one of items via the UI of  FIG. 33A  and  FIG. 33B  and sets the selected value, the broadcast receiver processes a color temperature of the received data and provides the processed result. 
         [0325]      FIG. 34  is a conceptual diagram illustrating a method for initializing an image setup value or a color temperature according to the present invention. 
         [0326]    When processing the received mobile service data, the broadcast receiver determines whether a user-defined image setup value or a user-defined color-temperature initialization command If the image setup value or the color-temperature initialization command exists, the broadcast receiver initializes a user-requested item according to a corresponding command, processes the initialization data, and provides the processed result. 
         [0327]    For example, the broadcast receiver provides an image setup value or a color-temperature adjusted data according to the above steps of  FIG. 32  and  FIG. 33 . In this case, the provided data may not satisfy the user. In this case, the broadcast receiver may output an initialization value in association with corresponding data. 
         [0328]    The above-mentioned initialization value may be either an image setup value or color temperature which has been prescribed in a corresponding broadcast receiver. Otherwise, the above-mentioned initialization value may be an image setup value or a color-temperature value which is the most appropriate for corresponding data. 
         [0329]    Next, an audio-language setup method for the broadcast receiver capable of processing/outputting received data will hereinafter be described. 
         [0330]      FIG. 35  shows an example for establishing an audio setup method according to the present invention. The example of  FIG. 35  relates to a language setup method from among audio setup methods. 
         [0331]    When processing/outputting the received data, the broadcast receiver provides information of at least one language associated with corresponding data, and provides the extracted information. In this case, at least one language may be extracted from program information (e.g., PSI/PSIP information) or audio information of mobile service data. 
         [0332]    The broadcast receiver determines whether a user&#39;s selection command for the provided language exists using the extracted information. If the user selects a specific language, the broadcast receiver can process the above-mentioned data using the selected language. 
         [0333]    If the user does not select the specific language or ignores it, the broadcast receiver may output corresponding data using languages prescribed in the broadcast receiver. If the predetermined language of the broadcast receiver is not contained in languages capable of being supported by corresponding data, the broadcast receiver selects either one of the above supportable languages, processes corresponding data using the selected language, and provides the processed result. 
         [0334]    In  FIG. 35 , provided that the received data can support Korean, English, and Chinese, the output language capable of being displayed on the broadcast receiver is one of the above three languages. In this case, if the user selects any one of the three languages, the broadcast receiver processes the corresponding data using the selected language, and outputs the processed result. 
         [0335]    Next, another audio setup method will hereinafter be described.  FIG. 36A  and  FIG. 36B  show another example of an audio setup method according to the present invention.  FIG. 36A  and  FIG. 36B  relate to the audio output setup method. 
         [0336]    While the received data is processed and outputted, the broadcast receiver determines the presence or absence of the user&#39;s setup command associated with the audio output. If the user setup command exists, the broadcast receiver can adjust an audio output of the processed data. However, if the user setup command does not exist, a transmission end of the broadcast receiver may adjust the audio output according to the audio output information suitable for the data, and may adjust the audio output according to a receiver&#39;s predetermined value. 
         [0337]      FIG. 36A  shows an example for adjusting an audio output setup value of corresponding data by a user. For example, if the user establishes a treble value, a base value, a balance value, and a sound-effect value, the broadcast receiver can process the audio output of the above-mentioned data according to the established values. In this case, in the case of the sound-effect value, various values may be used to indicate the sound effect, for example, OFF value, 3D-echosound value, SRS value, and Dolby value. 
         [0338]    As can be seen from  FIG. 36B , the user can adjust the audio output setup value according to corresponding data characteristics. For example, items of  FIG. 36A  are pre-established according to data categories (e.g., news, music, or movie). Thereafter, if the user selects a news item, the broadcast receiver adjusts the audio output of corresponding news data according to values prescribed in news items, and outputs the adjusted result. The music item includes at least one of pop, classic, and jazz. 
         [0339]    Next, an auto-time setup method for use in the broadcast receiver will hereinafter be described. 
         [0340]      FIG. 37  is a flow chart illustrating an automatic channel setup method according to another embodiment of the present invention. 
         [0341]    When the received data is processed and outputted, the broadcast receiver determines whether the user enters an auto-time setup command. If the auto-time setup command exists, program information (e.g., STT of PSIP) of mobile service data is updated such that the broadcast receiver receives time information. 
         [0342]    The transmission end transmits incorrect time information, so that the number of errors capable of being generated from the broadcast receiver is minimized. 
         [0343]    As shown in  FIG. 37 , if the user switches on the auto-time setup mode, a time-zone item and a daylight-saving item can be established. For example, in the United States, one of Eastern, Central, Mountain, Pacific, Alaska, and Hawaii is selected as a reference for the auto-time setup. Either one of “ON”, “OFF”, and “AUTO” may be selected as the “daylight saving”. In this case, the “ON” case indicates that the daylight saving is always applied and the OFF is not applied. The “AUTO” determines whether daylight saving is automatically applied on the basis of a Rx signal. 
         [0344]    A manual-time setup method for the broadcast receiver will hereinafter be described. 
         [0345]      FIG. 38  is a flow chart illustrating a manual channel setup method according to another embodiment of the present invention. 
         [0346]    When the broadcast receiver processes and outputs the received data, the broadcast receiver determines whether a manual-time setup command exists. If the manual-time setup command exists, the broadcast receiver may display the manual-time setup command and input information on the screen. In this case, the input information may include day, time, date, month, and year information. If the manual-time setup command process is activated after the auto-time setup of  FIG. 37  has been executed, the predetermined auto-time may be outputted as a default value. However, upon receipt of a manual time entered by the user, the auto-time setup may be switched to “OFF”. 
         [0347]    Next, a method for establishing other time information (i.e., additional time-information setup method) using the broadcast receiver will hereinafter be described.  FIG. 39  shows an example of another time information setup method according to the present invention. 
         [0348]    The broadcast receiver determines the presence or absence of additional time-information setup command when it processes/outputs the received data. If a setup command associated with additional time information exists, the broadcast receiver establishes time information, and controls the output of corresponding data according to the established time information. 
         [0349]    In the above-mentioned description, the additional time information may include at least one of an off-timer, an On-timer, and an alarm time. 
         [0350]    For example, if an off-time has been established by the user, the broadcast receiver establishes time information at which the broadcast receiver will be switched off according to an off-timer setup command. If a current time reaches the above-mentioned OFF-timer time during the processing time of the Rx data, data is not displayed, and the broadcast receiver is switched off. 
         [0351]    If the On-timer is established by the user, the broadcast receiver receives the ON-timer setup command and establishes time information at which the broadcast receiver will be powered on. In this case, the established information may include time information, channel information, and audio size information. The broadcast receiver is automatically switched on if a current time reaches the ON-timer time. If the broadcast receiver is switched on, the broadcast receiver receives data according to the established channel information and the audio-size information, and outputs the received data. 
         [0352]    If an alarm time is established by the user, the broadcast receiver establishes alarm-ON time information according to the alarm time setup command. Thereafter, if a current time reaches the alarm time, the broadcast receiver outputs the processed data and outputs the alarm signal as video or/and audio data. 
         [0353]    Next, an aspect-ratio setup method for the broadcast receiver will hereinafter be described.  FIG. 40A  and  FIG. 40B  show a method for establishing an aspect ratio according to the present invention. 
         [0354]    Referring to  FIG. 40 , the broadcast receiver receives the program at step S 4040 , processes the received program, and displays it at step S 4020 . The broadcast receiver determines whether the aspect-ratio conversion event occurs at step S 4030 . In this case, if the aspect-ratio conversion event occurs, the aspect ratio is selected at step S 4040 , and the image is displayed at the selected aspect ratio at step S 4050 . 
         [0355]    There are two aspect-ratio selection methods. One method is an automatic aspect-ratio selection process, and the other method is a manual aspect-ratio selection process. 
         [0356]    The automatic aspect-ratio selection process employs aspect-ratio information contained in Tx (transmission) data. The aforementioned aspect-ratio information may be contained in video data. The aspect ratio is applied to the displayed program according to aspect-ratio information, so that the result is displayed. 
         [0357]    According to the manual setup process, the broadcast receiver uses information of the user-selected aspect ratio. In the manual setup process, the user may select any one of “4:3”, “16:9”, “Horizon”, “zoom 1”, “zoom 2”, and “Cinema Zoom”, as shown in  FIG. 40B . 
         [0358]    In this case, the broadcast receiver adjusts the aspect ratio of data processed by the selected aspect-ratio, and outputs the adjusted result. Namely, if the user selects any one of items of  FIG. 40B , the broadcast receiver adjusts the aspect ratio of the image to be displayed, and outputs the adjusted result. 
         [0359]    Next, a method for establishing caption-associated information for use in the broadcast receiver will hereinafter be described. 
         [0360]      FIG. 41A  and  FIG. 41B  show an example for establishing caption-associated information according to the present invention. In this case, the caption-associated information may be caption language. 
         [0361]    Namely, the broadcast receiver receives a program at step S 4110 , processes the received program, and displays it at step S 4120 . 
         [0362]    When displaying the program, the broadcast receiver determines the presence or absence of an output command of caption data at step S 4130 . 
         [0363]    If the output command of the caption data exists, the broadcast receiver extracts the caption data at step S 4140 , extracts information data of the caption data, and determines whether there are several numbers of caption languages at step S 4150 . 
         [0364]    If there are several caption languages at step S 4150 , the broadcast receiver determines whether the caption language change event occurs at step S 4160 . 
         [0365]    If the caption language change event has occurred at step S 4160 , the broadcast receiver selects a caption language of the output program at step S 4170 , and outputs the selected caption language at step S 54180 . 
         [0366]    In this case, if the number of caption languages in the caption data is only one, only corresponding caption language is displayed. If there are several caption languages and the caption language change event does not occur, the broadcast receiver selects the caption language primarily established in a corresponding program, and outputs the selected language. 
         [0367]    If the caption language is selected at step S 4170 , the broadcast receiver outputs the UI of  FIG. 41B  and may also allow the user to select the caption language. In this case, the UI may be differently configured according to the number of caption languages contained in output caption data. 
         [0368]    For example, during the output time of the A program, if caption data exists and an output command for the caption data exists, the broadcast receiver extracts the caption data. The broadcast receiver determines whether there are several caption languages in the extracted caption data. For example, it is assumed that caption languages are Korean, English, and Chinese, and the user selects the Korean. The basic caption language of a corresponding program is changed to the user-selected caption language (i.e., the Korean). 
         [0369]    Next, another method for establishing caption-association information for the broadcast receiver will hereinafter be described.  FIG. 42A  is a flow chart illustrating a method for establishing caption-associated information according to the present invention. 
         [0370]    Referring to  FIG. 42A , the broadcast receiver receives the program at step S 4210 , and extracts caption data from the received program at step S 4220 . The broadcast receiver processes the extracted caption data and displays it at step S 4230 . 
         [0371]    After outputting the caption data, the broadcast receiver determines whether the caption end event occurs at step S 4240 . If the check-result caption end event has not occurred, the broadcast receiver determines whether the caption setup change event occurs at step S 4240 . 
         [0372]    If the caption setup change event has occurred, the caption setup is changed at step S 4250 . In order to extract/display the changed caption data, the broadcast receiver returns to the step S 4220 , so that the above-mentioned steps are repeated. 
         [0373]    When the caption setup is changed at step S 4250 , information associated with the caption setup may indicate style-associated information. A setup value of the style-associated information may include a Set-By-Program value and a custom value. The Set-By-Program value may indicate that data is displayed in the form of information loaded on a Tx stream of a current channel. The Custom value indicates that the aforementioned style information is changed to the user-selected value so that the changed result is displayed. 
         [0374]    The above-mentioned style information may include a variety of information of  FIG. 42B , for example, a caption size, a font, text color, a text opacity, a background color, background opacity, an edge type, and an edge color. 
         [0375]    The caption-size information may include a “Standard” setup value indicating a medium-sized character, a “Large” setup value indicating a large-sized character, and a “Small” setup value indicating a small-sized character. 
         [0376]    Information associated with the caption font may include font setup values (Font 0 ˜Font 7 ). The font setup value (Font 0 ) may indicate a specific design font developed by a manufacturing company of the receiver. The font setup value (Font 1 ) indicates “courier”, the font setup value (Font 2 ) indicates “times new roman”, the font setup value (Font 3 ) indicates “helvetica monospace”, the font setup value (Font 4 ) indicates “arial”, the font setup value (Font 5 ) indicates “MS comics”, the font setup value (Font 6 ) indicates “Cursive”, and the font setup value (Font 7 ) indicates a small capital. 
         [0377]    For example, the caption-text color information may include any one of setup values, i.e., white, black, red, green, blue, yellow, magenta, and cyan values. 
         [0378]    The caption-text transparency information may include any one of setup values, i.e., a solid setup value, translucent setup value, a transparent setup value, a flash setup value, and a manual-control setup value. 
         [0379]    By the solid setup value, the caption text becomes opaque. By the translucent setup value, the caption text becomes semitransparent. By the transparent setup value, the caption text becomes transparent. By the flash setup value, the transparent and opaque states are repeated at intervals of a predetermined time. By the manual-control setup value, the user can adjust the caption text. 
         [0380]    The caption-background color information may have the same value as the caption-text color information as a background-color setup value. Namely, the caption-background color information may include any one of setup values, i.e., white, black, red, green, blue, yellow, magenta, and cyan values. 
         [0381]    The caption-background transparency information may be equal to the caption-text transparency information. Namely, the caption-background transparency information may include any one of setup values, i.e., a solid setup value, translucent setup value, a transparent setup value, a flash setup value, and a manual-control setup value. 
         [0382]    The caption-edge type information may include at least one of “None”, “Uniform”, “Raised”, “Depressed”, “Left shadow”, and “Right Shadow”. In this case, “None” indicates that there is no edge of the letter or character, “Uniform” indicates that a general edge exists, “Raised” is the embossing part, “Depressed” is the engraved part, “Left shadow” is the presence of a left shadow, and “Right Shadow” is the presence of a right shadow. 
         [0383]    The caption-edge color information may have the same value as the caption-text color information setup value. Namely, the above-mentioned setup value may include any one of setup values, i.e., white, black, red, green, blue, yellow, magenta, and cyan values. 
         [0384]    Therefore, upon receiving style-associated information of the program, the broadcast receiver prevents the user from accessing at least one information from among the style-associated information (i.e., caption size, font, text color, text opacity, background color, background opacity, edge type, and edge-color information). Otherwise, upon receiving a custom value setup command as a style-associated information setup value, the broadcast receiver can allow the user to access individual information of the style-associated information. 
         [0385]    Next, an On Screen Display (OSD) setup method for the broadcast receiver will hereinafter be described.  FIG. 43A  is a flow chart illustrating an OSD setup method according to the present invention. 
         [0386]    Referring to  FIG. 43A , the broadcast receiver receives the program at step S 4310 , processes the received program, and displays the processed result at step S 4230 . 
         [0387]    After displaying the processed result, the broadcast receiver determines whether the OSD output event occurs at step S 4330 . If the OSD output event has occurred, the broadcast receiver determines whether the OSD language change event has occurred at step S 4340 . 
         [0388]    If the OSD language change event has occurred at step S 4340 , the OSD language is changed at step S 4350 . 
         [0389]    For example, the OSD language may be changed to another language by the User Interface (UI) of  FIG. 43B . as can be seen from  FIG. 43B , the OSD language capable of being selected may include Korean, English, Spanish, and French. In this case, each OSD language may be represented by unique languages of a corresponding country. For example, Korean is denoted by “          (KOREAN)”, English is denoted by “ENGLISH”, Spanish is denoted by “Espanol (SPANISH)”, and French is denoted by “Franais (FRENCH)”. 
         [0390]    Next, a Picture-In-Picture (PIP) control method for the broadcast receiver for processing mobile service data will hereinafter be described. 
         [0391]    Namely, when the Tx program is processed and outputted, the broadcast receiver generates and provides a main image and a sub-image by a user&#39;s PIP setup command. IN this case, if the PIP control command exists, the broadcast receiver can control the provided PIP. 
         [0392]    For example,  FIG. 44A  is a conceptual diagram illustrating a PIP control method according to the present invention. In  FIG. 44A , a first image (i.e., a main image) includes a sub-image  4420  and a sub-image control window  4410 . In this case, the receiver can control the size and position of the sub-image according to the user&#39;s control command received from the sub-image control window  4410 . 
         [0393]      FIG. 44B  is a conceptual diagram illustrating another PIP control method according to the present invention.  FIG. 44B  shows a first image (i.e., a main image)  4430  and a second image (i.e., a sub-image)  4440 . However, differently from  FIG. 44A , the sub-image is not present in the main image  4430  in  FIG. 44B , and the main image  4430  and the sub-image  4440  may coexist without overlapping with each other. 
         [0394]    Under the above-mentioned case, the broadcast receiver can control each screen or each image. For example, if the user enters a control command of the size of the sub-image  4440  via the control window  4450 , the broadcast receiver controls the size of the sub-image  4440 . In this case, the size of the main image  4430  may increase in proportion to the size of the sub-image  4440 . When either one of images is controlled, the size or position of another image is maintained, and the size or position of only the controlled image can be changed. 
         [0395]      FIG. 44B  shows an exemplary control window  4450 . The present invention can control the size of the control window  4450 , and can control the position of the control window  4450  as shown in  FIG. 44A . 
         [0396]    Next, a menu-display control method for the broadcast receiver for processing/displaying mobile service data will hereinafter be described.  FIG. 45A  and  FIG. 45B  show a method for controlling the menu display according to the present invention. 
         [0397]    Namely, the broadcast receiver processes/provides mobile service data, generates menu images classified according to various functions, and displays the menu images. 
         [0398]    For example,  FIG. 45A  shows a first depth  4510  and a second depth  4511 . In this case, the above-mentioned depth is a general term of menu items of the same level. 
         [0399]    Namely, when the broadcast receiver configures a first menu display, the first depth  4510  is displayed. If the user selects either one of items from among menu items shown in the first depth  4510 , the second depth  4511  corresponding to a detailed menu associated with the selected item is configured and provided to the user. 
         [0400]    If a third depth associated with the second depth  4511  exists and the user enters either one of items from among the second depth, the broadcast receiver provides a third depth according to the user selection signal. 
         [0401]      FIG. 45B  shows the first depth  4520  and the second depth  4521  as shown in  FIG. 45A . On the first depth  4520  of  FIG. 45A , individual menu items are configured in the form of a vertical structure. On the first depth  4520  of  FIG. 45B , individual menu items are arranged in the form of icons. 
         [0402]    Therefore, if the user navigates individual menu items of the first depth, selects any one of items, or enters a number corresponding to the menu item, the broadcast receiver configures and provides the second depth. 
         [0403]      FIG. 45C  shows horizontal-structured menu items contained in the first depth, differently from  FIG. 45A  and  FIG. 45B . The menu items of  FIG. 45C  can be shifted to the right or left side, and be selected by the user. Needless to say, the user may select the above menu items using any number buttons. 
         [0404]    If the user selects any one of menu items from among the first depth  4530 , the broadcast receiver configures the second depth  4531 , and provides the configured second depth  4531 . In this case, if the second depth  4531  is not fully displayed on a single screen or image, the up-and-down navigation is made as shown in the first depth, or menu items may also be displayed in the form of icons as shown in the first depth of  FIG. 45B . 
         [0405]    As shown in  FIG. 45D , the broadcast receiver configures menu display formats in the form of a tree. Namely, only upper concepts including lower concepts are initially displayed on the first window  4540 . If the user selects a menu item indicating any one of upper concepts, the broadcast receiver is connected to a lower part underneath the selected menu item, such that the lower concept can be displayed. Therefore, from the viewpoint of a user, the organic relationship between individual items can be easily recognized. 
         [0406]    The broadcast receiver includes “Conversion”, “Confirm”, and “Previous” buttons on the second window  4541 , so that it can control the first window  4540  using the above-mentioned buttons. 
         [0407]    For example, if the “Conversion” button is selected on the second window  4541 , the user can change a current tree-type menu display to the first-depth-type menu display selected from among those of  FIG. 45A  to  FIG. 45C . 
         [0408]    “Confirm” and “Previous” may be used to move to the upper and lower concepts of the tree-type menu display. 
         [0409]    As apparent from the above description, in the case of using the digital broadcast system and the data processing method according to the present invention, when mobile service data and PSI/PSIP information associated with the mobile service data are transmitted over a channel, the digital broadcast system has very resistant to errors and is easily compatible with conventional receivers. 
         [0410]    The digital broadcast system can normally receive mobile service data packet without any errors over a poor channel which has lots of ghosts and noises. 
         [0411]    The digital broadcast system inserts known data at a specific location of a data region, and performs signal transmission, thereby increasing the Rx performance under a high-variation channel environment. 
         [0412]    The digital broadcast system multiplexes the mobile service data to main service data according to a burst structure, thereby reducing the power of Rx system. 
         [0413]    The digital broadcast system can be more effectively used for mobile phones or mobile receivers, channel conditions of which are excessively changed and are weak resistances to noise. 
         [0414]    Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. 
         [0415]    It should be noted that most terminology disclosed in the present invention is defined in consideration of functions of the present invention, and can be differently determined according to intention of those skilled in the art or usual practices. Therefore, it is preferable that the above-mentioned terminology be understood on the basis of all contents disclosed in the present invention. 
         [0416]    It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.