Abstract:
A mobile digital signal transceiving device comprises a multimedia interface, a processing unit and a radio frequency (RF) signal transmitter. The multimedia interface reads at least one multimedia data stored in at least one multimedia memory device. The processing unit transfers the multimedia data into a terrestrial broadcast data in a digital video broadcasting-terrestrial (DVB-T) data format, and modulates the terrestrial broadcast data in order to generate an RF signal. The RF signal transmitter transmits the RF signal so that the RF signal may be received by at least one mobile multimedia device.

Description:
[0001]    This application claims the benefit of Taiwan Patent Application Serial No. 097141965, filed Oct. 31, 2008, the subject matter of which is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    (1) Field of the Invention 
         [0003]    The invention relates to a device for mobile digital signal transceiving and, more particularly, to a device that transceives multimedia data of a mobile multimedia memory apparatus in a DVB-T (digital video broadcasting-terrestrial) data format. 
         [0004]    (2) Description of the Prior Art 
         [0005]    Satellite technology has made our life more convenient in various ways. In our daily life, products that support global satellite positioning, satellite telecommunicating, satellite broadcasting, satellite navigating or the like, have brought people closer geographically, which have put the world under a global village. Moreover, satellite broadcasting has realized “real-time” TV programs in the broadcasting industry, which renders it possible to play various programs at every corner of the world. 
         [0006]    In the prior art, the satellite broadcasting technology may generally be classified into stationary broadcasting and mobile broadcasting. In stationary broadcasting, it is required to have a DVB-S/DVB-T (digital video broadcasting-satellite/digital video broadcasting-terrestrial) signal-transceiving base station constructed on the ground or a suitable fixed construction. Furthermore, satellite parameters are downloaded so as to direct an antenna toward a desired satellite, thereby establishing a bi-directional signal and data link between the base station and the satellite. However, due to the lack of mobility and the limitation in transmission power, stationary broadcasting may only provide limited field coverage. As a result, areas outside the field coverage may not receive DVB-T signals. 
         [0007]      FIG. 1  is a schematic view illustrating a DVB-S/DVB-T base station and its field coverage in a communication system. Referring to  FIG. 1 , the system may include a DVB-S/DVB-T signal transceiving base station  100 , which may refer to a construction on the ground or an apparatus on top of a construction, a satellite  200  for broadcasting TV programs that orbits around the Earth, and a plurality of digital TVs, for example, TVs  300 ,  300   a  and  300   b,  either stationary or mobile with respect to the station  100 . 
         [0008]    The satellite  200  broadcasts a DVB-S signal S 1  that may contain at least a satellite program. The DVB-S/DVB-T signal transceiving base station  100  receives the DVB-S signal S 1  and processes the signal S 1  by, for example, editing, cutting, integrating, dubbing, synchronous translating, and/or captioning. Then, the processed signal is encoded so as to generate a corresponding DVB-T signal S 2  containing the at least one satellite program. The DVB-S/DVB-T signal transceiving base station  100  broadcasts the DVB-T signal S 2  in a field coverage ER 0 , which represents a range of the broadcasting service. In application, the range of the field coverage ER 0  may be subject to the structure of the DVB-S/DVB-T signal transceiving base station  100 , weather conditions and terrestrial features. Accordingly, the size of the field coverage ER 0  may vary over time. 
         [0009]    In the present example, the digital TV  300  is located within the field coverage ER 0 , while the other digital TVs  300   a  and  300   b  are located outside the field coverage ER 0 . Accordingly, only the digital TV  300  can receive the DVB-T signal S 2  from the DVB-S/DVB-T signal transceiving base station  100  and display programs provided by the satellite  200  via the base station  100 . 
         [0010]    Due to the aforesaid limitations in stationary broadcasting, mobile broadcasting is introduced. In mobile broadcasting, an antenna system, which may be mounted on a satellite news gathering (SNG) vehicle, is used for tracking satellites and processing bi-directional signal and data communication when a target satellite is locked on. 
         [0011]      FIG. 2  is a diagram illustrating a mobile satellite system  1  located outside the field coverage ER 0  of the DVB-S/DVB-T signal transceiving base station  100 . Referring to  FIG. 2 , the mobile satellite system  1  may be mounted on a vehicle such as an SNG vehicle in the vicinity of the digital TVs  300   a  and  300   b  for transmitting the satellite programs provided by the satellite  200 . The mobile satellite system  1  includes a DVB-S antenna  11  and a DVB-T signal transceiver  12 . 
         [0012]    The DVB-S antenna  11  receives the DVB-S signal S 1  from the satellite  200 , forms a DVB-T signal S 3  by editing the signal S 1  and encoding the edited signal, and then broadcasts the signal S 3  containing the satellite programs via the DVB-T signal transceiver  12 . The mobile satellite system  1  may establish another field coverage ER′ to cover the digital TVs  300   a  and  300   b  within range of service. With such an arrangement, the digital TVs  300   a  and  300   b  can display the satellite programs provided by the satellite  200  through the mobile satellite system  1 , while the digital TV  300  displays the satellite programs through the DVB-S/DVB-T signal transceiving base station  100 . 
         [0013]    Though the mobile broadcasting technology provides a solution to overcome the limitations of the stationary broadcasting technology, the mobile broadcasting technology may have some disadvantages yet to resolve, as discussed below. 
         [0014]    Firstly, because the DVB-S signal S 1  cannot be directly utilized by the digital TVs, the mobile satellite system  1  to serve as an intermediate station is generally required. Moreover, to facilitate the optimal performance of the mobile satellite system  1 , a well-equipped SNG vehicle rather than general vehicles such as sedans, pickups, trucks and vans is often required, which may hinder mobile broadcasting from popularization. 
         [0015]    Secondly, the DVB-S signal S 1  needs to be processed to a certain extent in the mobile satellite system  1  before the processed signal is forwarded to clients (i.e., digital TVs). Such processing may incur additional cost and may inevitably result in a complicated mobile satellite system. 
         [0016]    Thirdly, in the case that a favorite satellite program needs to be recorded while the user of the digital TV is not available, the mobile is satellite system  1  may not provide a delay download service or a relatively large memory for storing the favorite programs. 
         [0017]    Fourthly, there is an increasing need for a portable multimedia memory device to record the programs broadcasted from the mobile satellite system  1  or directly from the satellite  200 . Currently, the mobile satellite system  1  and some market products may not support this function. 
         [0018]    Therefore, a need may exist for a more convenient mobile digital signal transceiving device. It may be desirable to have a device that is applicable to general vehicles and capable of downloading satellite programs. 
       SUMMARY OF THE INVENTION 
       [0019]    Accordingly, it is an object of the present invention to provide a mobile digital signal transceiving device, by which multimedia data stored in portable multimedia memory devices such as DVDs, CDs, MDs, SD cards and/or mobile disks can be retrieved and a corresponding radio frequency signal in a DVB-T format can be generated for a terrestrial broadcasting purpose so that the radio frequency signal may be received by at least a mobile multimedia apparatus. 
         [0020]    It is another object of the present invention to provide a simple-structured mobile digital signal transceiving device for receiving a DVB-T signal, by which multimedia data carried by the DVB-T signal can be transformed in a DVB-T format into terrestrial broadcasting data and thereafter be further transformed into a radio frequency signal for broadcasting. 
         [0021]    It is a further object of the present invention to provide a mobile digital signal transceiving device with a multimedia interface, with which the received DVB-T signal may be transformed into respective multimedia data to be thereafter stored in a portable multimedia memory device. 
         [0022]    In the present invention, the mobile digital signal transceiving device includes a multimedia interface, a processing unit and a radio-frequency (RF) signal transmitter. The multimedia interface establishes a pathway for retrieving, reading and/or accessing at least one multimedia data from respective portable multimedia memory device. The processing unit may transform the multimedia data into corresponding terrestrial broadcast data in a DVB-T data format, and may form a corresponding RF signal based on the terrestrial broadcast data. The RF signal transmitter may transmit the RF signal so that the RF signal may be received by at least a mobile multimedia apparatus. 
         [0023]    In a preferred embodiment of the present invention, the mobile digital signal transceiving device is mounted on a vehicle and may receive DVB-T signals transmitted from a DVB-S/DVB-T signal transceiving base station. In the case that the received DVB-T signal carries multimedia data, the mobile digital signal transceiving device of the present invention may transform the multimedia data into a terrestrial broadcast signal in the DVB-T data format, and transform the terrestrial broadcast signal into an RF signal for broadcasting. Then, all the mobile multimedia apparatuses within the field coverage of the mobile digital signal transceiving device may receive the RF signal corresponding to the DVB-T signal originally transmitted from a DVB-S/DVB-T signal transceiving base station. 
         [0024]    In one embodiment of the present invention, the mobile digital signal transceiving device may be coupled with at least a multimedia R/W device, or built in a multimedia R/W unit, such that multimedia data stored in DVDs, CDs, MDs, SDs and portable hard disks may be readable. Also, the received DVB-T signal may be transformed into corresponding multimedia data, which may then be stored in the multimedia R/W device/unit. 
         [0025]    In one embodiment of the present invention, a broader joint field coverage can be achieved by introducing at least two aforesaid mobile digital signal transceiving devices. 
         [0026]    By providing the mobile digital signal transceiving device of the present invention to accompany the DVB-S/DVB-T signal transceiving base station, a field coverage of the base station may be substantially extended in an economical manner. 
         [0027]    Since the mobile digital signal transceiving device of the present invention may be equipped with the multimedia interface, multimedia data stored in a portable multimedia memory device can be read and can be further transformed into a corresponding RF signal in a DVB-T data format, in which the RF signal can be preferably transmitted through at least a transmission band. 
         [0028]    Furthermore, by providing the multimedia interface to the mobile digital signal transceiving device of the present invention, multimedia data carried by the DVB-T signal can be written into a portable multimedia memory device connected with the mobile digital signal transceiving device. With such an arrangement, the mobile digital signal transceiving device of the present invention needn&#39;t provide a large-scaled built-in memory, which may incur a substantial cost. 
         [0029]    All these objects are achieved by the mobile digital signal transceiving device described below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    The present invention will be specified with reference to its preferred embodiments illustrated in the drawings, in which: 
           [0031]      FIG. 1  is a schematic view illustrating a DVB-S/DVB-T base station with a field coverage; 
           [0032]      FIG. 2  is a diagram illustrating a communication environment after adding a mobile satellite system to that of  FIG. 1 ; 
           [0033]      FIG. 3  is a schematic view of a mobile vehicle carrying a mobile digital signal transceiving device in accordance with an embodiment of the present invention; 
           [0034]      FIG. 4  is a schematic view of a communication environment including one mobile digital signal transceiving device of the present invention; 
           [0035]      FIG. 5  is a block diagram of a mobile digital transceiving device in accordance with an embodiment of the present invention; 
           [0036]      FIG. 6  is a block diagram of a mobile digital transceiving device in accordance with another embodiment of the present invention; and 
           [0037]      FIG. 7  is a schematic view of a communication environment including two mobile digital signal transceiving devices of the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0038]    The invention disclosed herein is directed to a mobile digital signal transceiving device. In the following description, numerous details are set forth in order to provide a thorough understanding of the present invention. It will be appreciated by one skilled in the art that variations of these specific details are possible while still achieving the results of the present invention. Under such a circumstance, there are two preferred embodiments described herein and a flowchart applied for both embodiments is provided to illustrate the present invention in details. 
         [0039]    Referring now to  FIG. 3  to  FIG. 5 ,  FIG. 3  illustrates a schematic view of a mobile vehicle carrying the mobile digital signal transceiving device in accordance with the present invention,  FIG. 4  is a schematic view of a communication environment including one mobile digital signal transceiving device of the present invention, and  FIG. 5  is a block diagram of a mobile digital transceiving device in accordance with an embodiment of the present invention. In the embodiment of the present invention, the mobile digital signal transceiving device  2  may be mounted on a vehicle  400 , which may include a terrestrial, marine or aerial vehicle. 
         [0040]    In the present invention, the mobile digital signal transceiving device  2  as shown in the embodiment may include a processing unit  21 , a DVB-T signal receiver  22 , an RF signal transmitter  23 , a multimedia interface  24 , a connection interface  25  and a multimedia data memory unit  26 . The processing unit  21  further includes a multiplexer  211 . The DVB-T signal receiver  22 , the RF signal transmitter  23 , the multimedia interface  24  and the multimedia data memory unit  26  are coupled electrically with the processing unit  21 . The connection interface  25  includes, for example, six connection ports  251 ,  252 ,  253 ,  254 ,  255  and  256 , each of which is coupled electrically with the multimedia interface  24 . 
         [0041]    A portable hard disk  500 , a DVD R/W device  500   a,  a CD R/W device  500   b,  an MD W/R device  500   c,  an SD R/W device  500   d  and a PS (play station series by Sony ) reading device  500   e  are connected to the connection ports  251 ,  252 ,  253 ,  254 ,  255  and  256 , respectively. The DVB-S/DVB-T signal transceiving base station  100  may be built on the ground or disposed on a construction. The program satellite  200  orbits in the space. A plurality of the mobile multimedia devices may be stationary or mobile devices. The mobile multimedia devices may include the digital TVs  300 ,  300   a  and  300   b.    
         [0042]    As previously described in the background, the DVB-S/DVB-T signal transceiving base station  100  may receive the DVB-S signal S 1  and process the signal S 1  by, for example, editing, cutting, integrating, dubbing, synchronous translating, and/or captioning. Then, the processed signal is encoded, thereby generating a corresponding DVB-T signal S 2  carrying satellite programs. The DVB-S/DVB-T signal transceiving base station  100  broadcasts the DVB-T signal S 2  in a field coverage ER 0 , which represents a range of the broadcasting service. 
         [0043]    In application, due to the time-varying nature of the field coverage ER 0 , the field coverage ER 0  may only cover the digital TV  300  and not the other digital TVs  300   a  and  300   b  at a certain time period. That is, only the digital TV  300  may effectively receive the DVB-T signal S 2 . 
         [0044]    However, as the mobile digital signal transceiving device  2  of the present invention mounted on the vehicle  400  is moved to a position within the field coverage ER 0 , as illustrated in  FIG. 4 , the DVB-T signal receiver  22  may then receive the DVB-T signal S 2  from the base station  100 , and send the DVB-T signal S 2  to the processing unit  21 . 
         [0045]    The processing unit  21  may decode the DVB-T signal S 2  into multimedia data and then store the multimedia data in the multimedia data memory unit  26 . Meanwhile, the processing unit  21  may transform the multimedia data into corresponding terrain broadcast data in a DVB-T data format, and then modulate the terrestrial broadcast data into an RF signal S 4  based on a broadcast time sequence. The RF signal S 4  is then sent to the RF signal transceiver  23 . The RF signal transceiver  23  broadcasts the RF signal S 4  simultaneously in at least a broadcast band within a field coverage ER 1 . 
         [0046]    With the aforesaid arrangement, the digital TV  300   a  and  300   b  originally located outside the ER 0  are covered by the ER 1 . Since the RF signal S 4  is modulated from the terrestrial broadcast data in the DVB-T data format, the digital TVs  300   a  and  300   b  may directly transform the received RF signal S 4  into corresponding multimedia data in order for display. 
         [0047]    In addition, when the portable hard disk  500 , DVD R/W device  500   a,  CD R/W device  500   b,  MD W/R device  500   c,  SD R/W device  500   d  and PS reading device  500   e  are correctly connected respectively to the connection ports  251 ,  252 ,  253 ,  254 ,  255  and  256 , a DVD, a CD, an MD, an SD card and/or a PS2 disc may be put respectively into the portable hard disk  500 , DVD R/W device  500   a,  CD R/W device  500   b,  MD W/R device  500   c,  SD R/W device  500   d  and/or the PS reading device  500   e  so that the portable multimedia storing means may retrieve the multimedia data stored in the multimedia data memory unit  26  through the multimedia interface  24 . The retrieved multimedia data is then sent to the processing unit  21 . 
         [0048]    The processing unit  21  may process the multimedia data stored in one of the aforesaid portable multimedia storing means, or the multimedia data carried by the DVB-T signal S 2 , or both. In the case that both multimedia data are processed, the multiplexer  211  may perform a synchronized multiprocessing. In one embodiment, the multiplexer  211  may store multimedia data from different sources in the multimedia data memory unit  26 . In another embodiment, the multiplexer  211  may transform the multimedia data into at least one terrestrial broadcast data in a DVB-T data format. The terrestrial broadcast data may be modulated into a corresponding RF signal S 4 , which may then be sent to the RF signal transmitter  23 . 
         [0049]    When the RF signal transmitter  23  broadcasts the RF signal S 4 , a plurality of broadcast bands may be available for multimedia data from various sources. For relatively large multimedia data, the multimedia data may be segmented into plural packages and then broadcast in the broadcast bands. 
         [0050]    The use of multiple broadcast bands for transmitting the RF signal S 4  in accordance with the present invention has at least the following advantages. 
         [0051]    Firstly, by switching the channels of the digital TV  300   a  or  300   b,  specific multimedia data out of the plural multimedia data from various sources may be located for display. That is, the mobile digital signal transceiving device  2  may serve as a base station for TV programs. For example, in defining the channels, the multimedia data from the DVB-T signal may be assigned to Channel  1 , those from the DVD may be assigned to Channel  2 , those from the CD may be assigned to Channel  3 , and so forth. 
         [0052]    Secondly, for some multimedia data, it may be convenient to have the data segmented and then to present each segment to a corresponding channel of the digital TV  300   a  or  300   b.  With such an arrangement, a user may be allowed to choose a desired channel (a specific segment of the multimedia data) while skipping the other parts of the multimedia data. For example, a relatively long TV program may be segmented into three data packages during transmission, and the digital TV  300   a  may present the first data package to channel  1 , the second data package to channel  2 , and the third data package to channel  3 . 
         [0053]    Furthermore, in the case that the multimedia data memory unit  26  has excessive multimedia data, parts of the stored multimedia data may be moved to an external hard disk  500  through the multimedia interface  24 , or written into the DVD, CD, MD, SD card and/or PS2 disc of the corresponding portable multimedia storing means. With such an arrangement, memory space in the multimedia data memory unit  26  may be timely released. 
         [0054]    In the aforesaid first embodiment of the present invention, the connection ports  251 ,  252 ,  253 ,  254 ,  255  and  256  are utilized to connect externally to the hard disk  500 , DVD R/W device  500   a,  CD R/W device  500   b,  MD R/W device  500   c,  SD card R/W device  500   d  and PS2 reading device  500   e,  respectively. In another embodiment of the present invention, some of the multimedia R/W devices may be built in the mobile digital signal transceiving device of the present invention. 
         [0055]      FIG. 6  is a block diagram of a mobile digital transceiving device  2   a  in accordance with another embodiment the present invention. As compared to the mobile digital transceiving device  2  of  FIG. 5 , the mobile digital signal transceiving device  2   a  includes a single connection port  25   a,  connecting externally to a portable hard disk  500 , which replaces the aforesaid connection interface  25  illustrated in  FIG. 5 . Furthermore, the multimedia R/W devices  271 - 275  may be integrated as a built-in multimedia R/W unit  27  of the mobile digital signal transceiving device  2   a  that is directly coupled with the multimedia interface  24 . 
         [0056]    The connection port  25   a  is electrically coupled to the multimedia interface  24 . The multimedia R/W unit  27  may include a DVD R/W device  271 , a CD R/W device  272 , an MD W/R device  273 , an SD R/W device  274  and a PS2 reading device  275  for receiving multimedia data from a DVD, a CD, an MD, an SD card and a PS2 disc, respectively. Further, the mobile digital signal transceiving device  2   a  in this embodiment and the mobile digital signal transceiving device  2  illustrated in  FIG. 5  are the same or at least similar in functions and operations. The RF signal emitted from the mobile digital signal transceiving device  2   a  is denoted as S 5 . 
         [0057]      FIG. 7  is a schematic view of a communication environment including a satellite  200 , a DVB-S/DVB-T signal transceiving base station  100 , the mobile digital signal transceiving device  2 , the mobile digital signal transceiving device  2   a,  and a plurality of digital TVs (three in the figure,  300 ,  300   a  and  300   b ). The DVB-S/DVB-T signal transceiving base station  100  receives the satellite signal S 1  from the satellite and transmits the DVB-T signal S 2  within the field coverage ER 0 . The mobile digital signal transceiving device  2  receives the DVB-T signal S 2  from the base station  100  and transmits the RF signal S 4  within the field coverage ER 1 . The mobile digital signal transceiving device  2   a  receives the RF signal S 4  from the mobile digital signal transceiving device  2  and transmits the RF signal S 5  within the field coverage ER 2 . With such an arrangement, the digital TV  300  may receive the DVB-T signal S 2  from the base station  100 , the digital TV  300   a  may receive the RF signal S 4  from the mobile digital signal transceiving device  2 , and the digital TV  300   b  may receive the RF signal S 5  from the mobile digital signal transceiving device  2   a.    
         [0058]    As compared to  FIG. 1  and  FIG. 2 , the coverage of the satellite  200  is substantially extended by introducing the mobile digital signal transceiving devices  2  and  2   a  of the present invention. 
         [0059]    The following advantages may be achieved. 
         [0060]    1. Since the mobile digital signal transceiving device  2  or  2   a  of the present invention does not directly receive the DVB-S signal from the satellite  200 , the mobile digital signal transceiving device  2  or  2   a  may have a simpler structure than the mobile satellite system  1  of  FIG. 2 . Also, the mobile digital signal transceiving device  2  or  2   a  may be easily mounted or carried by an ordinary vehicle, and thus the cost in constructing a carrier and providing sufficient instruments/parts to utilize the DVB-T signal may be substantially reduced. 
         [0061]    2. By providing the multimedia interface to the mobile digital signal transceiving device  2  or  2   a,  various multimedia data stored in most of the media storage means become available from the mobile digital signal transceiving device  2  or  2   a  to the digital TVs. 
         [0062]    3. In the case that the mobile digital signal transceiving device receives too-big-to-be-handled multimedia data carried by the DVB-T signal, the multimedia interface may write the multimedia data into a portable multimedia memory device. Therefore, when the multimedia data are to be broadcasted at a later time, the multimedia data may be readily available from the portable multimedia memory device. With such an arrangement, the mobile digital signal transceiving device needn&#39;t construct a built-in memory unit for storing huge multimedia data. 
         [0063]    4. In the case that at least two mobile digital signal transceiving devices are applied to the DVB-T/DVB-S base station, the integrated field coverage may be substantially enlarged to cover more stationary or mobile multimedia display devices under service. 
         [0064]    5. Though the mobile multimedia display devices used in the aforesaid embodiment of the present invention are defined to be the digital TVs, the mobile multimedia display devices in other embodiments may include any devices that can handle and display the RF signal in a DVB-T data format. 
         [0065]    The aforesaid mobile digital signal transceiving device  2  or  2   a  is portable and thus may be carried by a vehicle  400 , or removed from the vehicle  400  and used indoor or outdoor as a stationary unit. 
         [0066]    While the present invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be without departing from the spirit and scope of the present invention.