Patent Abstract:
A device is provided. the device comprises a maximum ratio combining (FD-MRC-DFE), a first device down stream to the FD-MRC-DFE; and a second device upstream to the maximum ratio combining (FD-MRC-DFE) having a second point directly connected to a first point within the first device. The method for producing the device is also provided.

Full Description:
CROSS-REFERENCE TO OTHER APPLICATIONS 
       [0001]    The following application of common assignee herewith is related to the present application, and is herein incorporated by reference in their entireties: 
         [0002]    U.S. patent application Ser. No. 12/512,901 with attorney docket number LSFFT-121. 
     
    
     FIELD OF THE INVENTION 
       [0003]    The present invention relates generally to an application in a digital television system, more specifically the present invention relates to a multiple tuner ATSC terrestrial DTV receiver for indoor and mobile users. 
       BACKGROUND 
       [0004]    Single carrier terrestrial digital television (DTV) systems are deployed in the countries such as Unite States (ATSC or Advanced Television Systems Committee), Canada, and other countries. 
         [0005]    For in-door or mobile users, accurate channel estimation during time periods between known, received intervals is required for receiving wireless signals. In addition to the superposition diversity of multiple tuner maximum ratio combining using Minimum Mean Square Error (MMSE) decision feedback equalization (see U.S. patent application Ser. No. 12/512,901), The challenge is to desirous to provide a receiver having accurate channel estimation during time periods between known, received intervals. 
       SUMMARY OF THE INVENTION 
       [0006]    A method and device for channel estimation in an in-door receiver is provided. 
         [0007]    A method and device for channel estimation in an in-door digital television (DTV) is provided. 
         [0008]    A method and device for channel estimation in an in-door terrestrial (DTV) is provided. 
         [0009]    A method and device for channel estimation in an in-door digital television (DTV) using a feedback signal from within a forward error control (FEC) block is provided. 
         [0010]    A method and device for channel estimation in an in-door single carrier digital television (DTV) using a feedback signal from within a forward error control (FEC) block is provided. 
         [0011]    A method and device for channel estimation in an mobile receiver is provided. 
         [0012]    A method and device for channel estimation in an mobile digital television (DTV) is provided. 
         [0013]    A method and device for channel estimation in an mobile terrestrial (DTV) is provided. 
         [0014]    A method and device for channel estimation in an mobile digital television (DTV) using a feedback signal from within a forward error control (FEC) block is provided. 
         [0015]    A method and device for channel estimation in an mobile single carrier digital television (DTV) using a feedback signal from within a forward error control (FEC) block is provided. 
         [0016]    A device is provided. The device comprises a maximum ratio combining (FD-MRC-DFE), a first device down stream to the FD-MRC-DFE; and a second device upstream to the maximum ratio combining (FD-MRC-DFE) having a second point directly connected to a first point within the first device. The method for producing the device is also provided. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0017]    The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention. 
           [0018]      FIG. 1A  is a first example of a first receiver in accordance with some embodiments of the invention. 
           [0019]      FIG. 1B  is a second example of a first receiver in accordance with some embodiments of the invention. 
           [0020]      FIG. 2  is a prior art ATSC standard. 
           [0021]      FIG. 3  is an example of a channel estimation diagram in accordance with some embodiments of the invention. 
           [0022]      FIG. 4  is an example of forming or obtaining a feedback signal from a FEC block in accordance with some embodiments of the invention. 
           [0023]      FIG. 5  is an example of a detailed channel estimation diagram between two known received sequences in accordance with some embodiments of the invention. 
           [0024]      FIG. 5A  is an example of a generic channel estimation diagram between two known received sequences in accordance with some embodiments of the invention. 
       
    
    
       [0025]    Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention. 
       DETAILED DESCRIPTION 
       [0026]    Before describing in detail embodiments that are in accordance with the present invention, it should be observed that the embodiments reside primarily in combinations of method steps and apparatus components related to carrier recovery, symbol/timing recovery, frequency down conversion, baseband signal filter, frame synchronization, and channel estimation for the received multiple channel signals from either single or multiple antennae with multiple tuners and then using channel decoder to overcome bad data or error in a coding context. Accordingly, the apparatus components and method steps have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. 
         [0027]    In this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “comprises . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element. 
         [0028]    Terms and phrases used in this document, and variations thereof, unless otherwise expressly stated, should be construed as open ended as opposed to limiting. As examples of the foregoing: the term “including” should be read as mean “including, without limitation” or the like; the term “example” is used to provide exemplary instances of the item in discussion, not an exhaustive or limiting list thereof; and adjectives such as “conventional,” “traditional,” “normal,” “standard,” and terms of similar meaning should not be construed as limiting the item described to a given time period or to an item available as of a given time, but instead should be read to encompass conventional, traditional, normal, or standard technologies that may be available now or at any time in the future. Likewise, a group of items linked with the conjunction “and” should not be read as requiring that each and every one of those items be present in the grouping, but rather should be read as “and/or” unless expressly stated otherwise. Similarly, a group of items linked with the conjunction “or” should not be read as requiring mutual exclusivity among that group, but rather should also be read as “and/or” unless expressly stated otherwise. 
         [0029]    It will be appreciated that embodiments of the invention described herein may be comprised of one or more conventional processors and unique stored program instructions that control the one or more processors to implement, channel estimation for received multiple channel signals. The non-processor circuits may include, but are not limited to, a radio receiver, a radio transmitter, signal drivers, clock circuits, power source circuits, and user input devices. As such, these functions may be interpreted as steps of a method to equalize the received multiple channel signals. Alternatively, some or all functions could be implemented by a state machine that has no stored program instructions, or in one or more application specific integrated circuits (ASICs), in which each function or some combinations of certain of the functions are implemented as custom logic. Of course, a combination of the two approaches could be used. Thus, methods and means for these functions have been described herein. Further, it is expected that one of ordinary skill, notwithstanding possibly significant effort and many design choices motivated by, for example, available time, current technology, and economic considerations, when guided by the concepts and principles disclosed herein will be readily capable of generating such software instructions and programs and ICs with minimal experimentation. 
         [0030]    The present invention contemplates a wireless receiver not only used in DTV systems, but also used in such wireless systems as a personal digital assistant (PDA), a mobile PC, an Internet PC, a cell phone, or any WiMax or LTE device, as well as any mobile indoor device. 
         [0031]    Referring to  FIG. 1A , an example of a first receiver  100  in accordance with some embodiments of the invention is shown. A received signal is received by antenna  102 . As can be seen, receiver  100  is a single antenna receiver such as a single antenna digital TV receiver with multiple tuners. In turn, a first tuner  104  processes the received signal r. The tuner  104  generate its proprietary signal to noise ratio based upon the tuner&#39;s noise characteristics. The received signal r, with tuner&#39;s noise characteristics, is subjected to preprocessing  106 . Preprocessing comprises down conversion, carrier recovery, symbol/timing recovery, base-band signal filter, frame synchronization, and Signal to Noise Ratio (SNR). In addition to these operations, a channel estimation block  103  receives the received signal r, and also receives a feedback signal A in order to generate an output  107 . After preprocessing, the respective signal  105 , along with its time domain channel estimation information  107 , are separately input into a FD-MRC-DFE (i.e. Frequency Domain Maximum Ratio Combining Decision Feedback Equalizer) block  108 . The output thereof is further subjected to down stream processing including Forward Error control (FEC)  110 , etc. Within the FEC unit  110 , the feedback A is generated. This forms the first signal path  112 . 
         [0032]    Similarly, for a second signal path  114 , the received signal r is received by antenna  102 . In turn, a second tuner  118  processes the received signal r. The tuners  118  generate its proprietary signal to noise ratio (SNR) based upon the tuner&#39;s noise characteristics. The received signal, with its noise characteristics, is subjected to preprocessing  120 . Preprocessing comprises down conversion, carrier recovery, symbol/timing recovery, base-band signal filter, frame synchronization, and Signal to Noise Ratio (SNR). In addition to these operations, a channel estimation block receives the received signal r, and also receives a feedback signal A in order to generate a channel estimation output. After preprocessing, the respective signal, along with its time domain channel estimation information, are separately input into a FD-MRC-DFE (i.e. Frequency Domain Maximum Ratio Combining Decision Feedback Equalizer) block  108 . The output thereof is further subjected to down stream processing including Forward Error control (FEC)  110 , etc. Within the FEC unit  110 , the feedback A is generated. This forms the first signal path  112 . 
         [0033]    Therefore, generically, of the Nth path  116 , the received signal is received by antenna  102 . In turn, a first tuner  122  processes the received signal. The tuners  122  generate its proprietary signal to noise ratio based upon the tuner&#39;s noise characteristics. The received signal, with its noise characteristics, is subjected to preprocessing  124 . 
         [0034]    Preprocessing comprises down conversion, carrier recovery, symbol/timing recovery, base-band signal filter, frame synchronization, and Signal to Noise Ratio (SNR). In addition to these operations, a channel estimation block  123  receives the received signal r, and also receives a feedback signal A in order to generate an output  125 . After preprocessing, the respective signal  123 , along with its time domain channel estimation information  125 , are separately input into a FD-MRC-DFE (i.e. Frequency Domain Maximum Ratio Combining Decision Feedback Equalizer) block  108 . The output thereof is further subjected to down stream processing including Forward Error control (FEC)  110 , etc. Within the FEC unit  110 , the feedback A is generated. This forms the first signal path  112 . 
         [0035]    Referring to  FIG. 1B , an example of a second receiver  200  in accordance with some embodiments of the invention is shown. A received signal r is received by a plurality of antennae comprising a set of N antennae (N being a natural number, with N greater than or equal to 2). Each antenna has its own tuner. Each antenna and an associated tuner form a signal path. 
         [0036]    A first tuner  204  processes the received signal r. The tuners  204  generate its proprietary signal to noise ratio based upon the tuner&#39;s noise characteristics. The received signal, with its noise characteristics, is subjected to preprocessing  206 . 
         [0037]    Preprocessing comprises down conversion, carrier recovery, symbol/timing recovery, base-band signal filter, frame synchronization, and Signal to Noise Ratio (SNR). In addition to these operations, a channel estimation block  203  receives the received signal r, and also receives a feedback signal A in order to generate an output  207 . After preprocessing, the respective signal  205 , along with its time domain channel estimation information  207 , are separately input into a FD-MRC-DFE (i.e. Frequency Domain Maximum Ratio Combining Decision Feedback Equalizer) block  108 . The output thereof is further subjected to down stream processing including Forward Error control (FEC)  110 , etc. Within the FEC unit  110 , the feedback A is generated. This forms the first signal path  112 . 
         [0038]    Similarly, for a second signal path  2022 , the received signal is received by antenna  2022 . In turn, a second tuner  218  processes the received signal. The tuners  218  generate its proprietary signal to noise ratio based upon the tuner&#39;s noise characteristics. The received signal, with its noise characteristics, is subjected to preprocessing  220 . 
         [0039]    Preprocessing comprises down conversion, carrier recovery, symbol/timing recovery, base-band signal filter, frame synchronization, and Signal to Noise Ratio (SNR). In addition to these operations, a channel estimation block  203  receives the received signal r, and also receives a feedback signal A in order to generate an output. After preprocessing, the respective signal, along with its time domain channel estimation information, are separately input into a FD-MRC-DFE (i.e. Frequency Domain Maximum Ratio Combining Decision Feedback Equalizer) block  108 . The output thereof is further subjected to down stream processing including Forward Error control (FEC)  110 , etc. Within the FEC unit  110 , the feedback A is generated. This forms the first signal path  112 . 
         [0040]    This forms the second signal path  212 . Note that only three paths are shown. However, in practice, up to N (N being a natural number, with N greater than or equal to 2) paths may be formed. 
         [0041]    Therefore, generically, of the Nth path  2024 , the received signal r is received by antenna  2024 . In turn, a Nth tuner  222  processes the received signal. The tuner  222  generate its proprietary signal to noise ratio based upon the tuner&#39;s noise characteristics. The received signal, with its noise characteristics, is subjected to preprocessing  224 . Preprocessing comprises down conversion, carrier recovery, symbol/timing recovery, base-band signal filter, frame synchronization, and Signal to Noise Ratio (SNR). In addition to these operations, a channel estimation block  103  receives the received signal r, and also receives a feedback signal A in order to generate an output  207 . After preprocessing, the respective signal  205 , along with its time domain channel estimation information  207 , are separately input into a FD-MRC-DFE (i.e. Frequency Domain Maximum Ratio Combining Decision Feedback Equalizer) block  108 . The output thereof is further subjected to down stream processing including Forward Error control (FEC)  110 , etc. Within the FEC unit  110 , the feedback A is generated. 
         [0042]    Referring to  FIG. 2 , a known ATSC diagram is shown. Note the time gap between field synchronization signals. The present invention addresses channel estimation between these gaps. 
         [0043]    Referring to  FIG. 3 , an example of channel estimation  300  is shown. A received signal r i  is input into a first Fourier transformers (FFT)  302 . The transformed, frequency domain signal R i  is subjected to divider  304 . Divider  304  has another input PN which is the transformed results of inputs subjected to a second fast Fourier transformers (FFT)  306 . There are two inputs for second fast Fourier transformers (FFT)  306  via a switch  308  that selectively selects a field synchronization signal  310  and a segment signal S SEGj  existing between two field synchronization signals  310  along a time line t. 
         [0044]    The quotient CE i  of divider  304  is the channel estimation, which is subjected to an inverse Fourier transformer (IFFT)  312  to be transformed back to the time domain ce i . The operations of  FIG. 3  are as follows. Between field synchronization signals  310  or in the gap,  310  segment signal S SEGj  (j=1, 2, . . . ) is used consecutively (for details, see figures infra). If the next or consecutive field synchronization signal  310  arrives, 
         [0045]    Referring to  FIG. 4 , the point of feedback A is shown. After  108 , the processed, received signal r enters  110 .  110  is further subdivided into a  1102  and  1104 , as well as other subdivided blocks further down stream. Between or from the output of  1102  and the input to  1104 , feedback A is formed or leads out to feed back to  203 / 103  of  FIGS. 1A-1B . 
         [0046]    Referring to  FIG. 5 , a detailed diagram depicting channel estimations between field synchronizations signals is shown. when time line progresses to a field synchronization FS, channel estimation is performed using the FS. However, between two FSs, there is no known sequence for channel estimation purposes. The present invention contemplates to advantageously use the Frequency Domain Maximum Ratio Combining Decision Feedback Equalizer (FD-MRC-DFE) processesed information to do the channel estimation. The FD-MRC-DFE process combines information from a plurality of tuners. In other words, channel information coming from tuners of other paths (see U.S. patent application Ser. No. 12/512,901) are combined and used for the channel estimation. Turning now to the drawings, FS signal is used for a typical, known channel estimation. Between FSs are the data portion of a transmission. The data portion is divided into segments (SEG 0 , . . . , SEG j , . . . , SEG m ). Each segment has an associated received signal r portion r SEGj . A is segmented into ce FS , ce SEG0 , ce SEG1 , . . . , ce SEGj , etc. But upon the FS signal is used and until the next FS signal occurs, one cannot rely with confidence on the previous FS for channel estimation. This is more true or evident under indoor or mobile circumstances. 
         [0047]    Referring to  FIG. 5A , a generic diagram depicting channel estimations between field synchronizations signals are shown. a plurality of received signals ri is input into block  108 , where i spans 1 to n. Similarly, a plurality of channel estimation signals ci is input into block  108 , where i spans 1 to n. 
         [0048]    It is noted that for in-door receivers, due to dynamic multipath resulting from living object (e.g. human) movement inside a man made or otherwise enclosure, channel estimation within the time gap between standard or known channel estimation is required. 
         [0049]    In the foregoing specification, specific embodiments of the present invention have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of present invention. The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.

Technology Classification (CPC): 7