Simultaneous demodulation and decoding of a digitally modulated radio signal using known symbols
First Claim
Patent Images
1. A method of transmitting and receiving digital data including unknown arbitrary information symbols, comprising the steps of:
- coding the unknown arbitrary information symbols and interleaving said unknown arbitrary information symbols, to separate adjacent unknown arbitrary information symbols from each other after they are coded;
inserting at least one known symbol next to one of at least two adjacent unknown arbitrary information symbols after the unknown arbitrary information are coded and interleaved;
decoding the one of said at least two adjacent unknown arbitrary information symbols which is next to said known symbol, to generate a decoded known symbol, anddecoding the other of said at least two adjacent arbitrary information symbols, to generate another decoded known symbol based on the previously decoded known symbol.
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Abstract
Systems and methods according to the present invention provide a combination of demodulation and decoding, termed decodulation herein. By using knowledge of known symbols, decoding known symbols first, and then using the information obtained by decoding known symbols to decode unknown symbols, improved performance can be achieved. This technique can also be used to alleviate the conventional 3dB loss suffered systems using differentially coding and modulation as compared to coherent detection systems.
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Citations
43 Claims
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1. A method of transmitting and receiving digital data including unknown arbitrary information symbols, comprising the steps of:
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coding the unknown arbitrary information symbols and interleaving said unknown arbitrary information symbols, to separate adjacent unknown arbitrary information symbols from each other after they are coded; inserting at least one known symbol next to one of at least two adjacent unknown arbitrary information symbols after the unknown arbitrary information are coded and interleaved; decoding the one of said at least two adjacent unknown arbitrary information symbols which is next to said known symbol, to generate a decoded known symbol, and decoding the other of said at least two adjacent arbitrary information symbols, to generate another decoded known symbol based on the previously decoded known symbol. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A decoding and demodulation apparatus for processing a coded, interleaved and modulated radio signal to extract digital information, comprising:
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means for producing numerical samples corresponding to a received radio signal that include at least one known symbol positioned next to at least two adjacent unknown arbitrary information symbols; means for storing a number of said numerical samples in a buffer memory; means for processing samples from said buffer memory, including; means for storing symbol sequence hypotheses which have been tested; means for storing a cumulative figure of merit or demerit for each of said tested sequences as path metrics; means for storing estimates of signal phase or amplitude at plural time positions corresponding to sample values in said buffer memory;
means for predicting a sample value based on said symbol sequence hypotheses and the estimates of signal phase or amplitude employing a model of said coding, interleaving and modulation;means for comparing said predictions with said numerical samples in said buffer memory and to produce mismatch values which are summed into said cumulative figure; means for selecting previous path metrics as a best predecessor for accumulating with said mismatch values such that said path metrics are the lowest possible, and means for updating said stored estimates after said selection and copying said updated, stored estimates from a memory location associated with said selected best predecessor to a memory location associated with a successor sequence hypothesis. - View Dependent Claims (16)
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17. A receiving apparatus for decoding blocks of coded and interleaved information signals that include at least one known symbol positioned next to at least two adjacent unknown arbitrary information symbols, comprising:
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de-interleaving means for selecting received signal samples alternately from a first received signal segment and a second received signal segment; and decoding means for decoding the one unknown arbitrary information symbol, which is next to said known symbol, to generate a decoded known symbol, and decoding the other adjacent arbitrary information symbol, which is not next to said known symbol, to generate another decoded known symbol based on the previously decoded known symbol. - View Dependent Claims (18, 19, 20, 21)
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22. A receiving apparatus for decoding blocks of coded and interleaved information signals that include at least one known symbol positioned next to at least two adjacent unknown arbitrary information symbols, comprising:
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de-interleaving means for selecting received signals samples from a first received signal segment and from a second received signal segment; and decoding means for decoding the one unknown arbitrary information symbol, which is next to said known symbol, to generate a decoded known symbol, and decoding the other adjacent arbitrary information symbol, which is not next to said known symbol, to generate another decoded known symbol based on the previously decoded known symbol. - View Dependent Claims (23, 24)
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25. A receiving apparatus decoding coded and interleaved information signals that include at least one known symbol positioned next to at least two adjacent unknown arbitrary information symbols, comprising:
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de-interleaving means for selecting a current symbol block of samples partly from a currently received signal segment and partly from at least one previously received segment; decoding means for decoding the one unknown arbitrary information symbol, which is next to said known symbol, to generate a decoded known symbol, and decoding the other adjacent arbitrary information symbol, which is not next to said known symbol, to generate another decoded known symbol based on the previously decoded known symbol. - View Dependent Claims (26, 27)
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28. A receiving apparatus for decoding coded and interleaved data symbol blocks that include at least one known symbol positioned next to at least two adjacent unknown arbitrary information symbols, comprising:
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de-interleaving means for selecting symbol blocks of received signal samples for decoding partly from a currently received signal segment and partly from at least one previously received signal segment; decoder means for decoding the one unknown arbitrary information symbol, which is next to said known symbol, to generate a decoded known symbol, and decoding the other adjacent arbitrary information symbol, which is not next to said known symbol, to generate another decoded known symbol based on the previously decoded known symbol; and processing means for processing said symbol blocks in which decoded known symbols from a later processed symbol block are used in reprocessing a previously processed symbol block to produce an improved corresponding decoded symbol block. - View Dependent Claims (29, 30)
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31. A receiving apparatus for decoding coded and interleaved data symbol blocks that include at least one known symbol positioned next to at least two adjacent unknown arbitrary information symbols, comprising:
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de-interleaving means for selecting symbol blocks of received signal samples for decoding partly from a currently received signal segment and partly from at least one previously received signal segment; decoder means for decoding the one unknown arbitrary information symbol, which is next to said known symbol, to generate a decoded known symbol, and decoding the other adjacent arbitrary information symbol which is not next to said known symbol, to generate another decoded known symbol based on the previously decoded known symbol; and processing means for processing said symbol blocks in which decoded known symbols from a currently decoded symbol block and decoded known symbols from a symbol block two symbol blocks prior to the currently decoded symbol block are used in reprocessing the symbol block processed just prior to the current symbol block to produce an improved decoded symbol block corresponding thereto. - View Dependent Claims (32, 33)
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34. A receiving apparatus for decoding coded and interleaved data symbol blocks that include at least one known symbol positioned next to at least two adjacent unknown arbitrary information symbols, comprising:
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de-interleaving means for selecting symbol blocks of received signal samples for decoding alternately from a first received signal segment and a second received signal segment; decoding means for decoding the one unknown arbitrary information symbol, which is next to said known symbol to generate a decoded known symbol, and decoding the other adjacent arbitrary information symbol, which is not next to said known symbol, to generate another decoded known symbol based on error check indications for the previously decoded known symbol; and error detection means for providing said error check indications. - View Dependent Claims (35)
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36. A system for transmitting and receiving digital information symbols, comprising:
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transmitter means for coding at least some of said digital information symbols for transmission, interleaving coded symbols with uncoded symbols and modulating said interleaved symbols on to a carrier signal, wherein said modulated coded and interleaved symbols that include at least one known symbol positioned next to at least two adjacent unknown arbitrary information symbols; means for receiving said carrier signal, filtering, amplifying, sampling and converting signal samples into a suitable form for processing; means for demodulating signal samples corresponding at least to said coded, interleaved and modulated symbols; and means for decoding the one unknown arbitrary information symbol, which is next to said known symbol, to generate a decoded known symbol, and decoding the other adjacent arbitrary information symbol, which is not next to said known symbol, to generate another decoded known symbol based on the previously decoded known symbol.
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37. A receiving apparatus for decoding signals modulated with coded and interleaved data symbol blocks that include at least one known symbol positioned next to at least two adjacent unknown arbitrary information symbols, comprising:
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de-interleaving means for selecting symbol blocks of received signal samples for decoding alternately from a first received signal segment and a second received signal segment; decoding means for decoding the one unknown arbitrary information symbol, which is next to said known symbol, to generate a decoded known symbol, and decoding the other adjacent arbitrary information symbol, which is not next to said known symbol, to generate another decoded known symbol based on reliability indications for the previously decoded known symbol; and decoding reliability indicator means for providing said reliability indications. - View Dependent Claims (38, 39)
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40. A receiving apparatus for demodulating and decoding information symbols that include at least one known symbol positioned next to at least two adjacent unknown arbitrary information symbols, wherein at least some of the unknown arbitrary information symbols are error correction coded and which are interleaved and modulated on to a radio signal comprising:
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means for receiving said radio signal; means for converting said received radio signal into a suitable form for sampling; means for sampling said converted radio signal and converting samples into numerical values related to instantaneous amplitude and values related to instantaneous phase; and means for processing said numerical values to demodulate and decode them and to produce decoded symbols corresponding to said coded information symbols, wherein the one unknown arbitrary information symbol, which is next to said known symbol, is decoded first to generate a decoded known symbol, and the other adjacent arbitrary information symbol, which is not next to said known symbol, is decoded next to generate another decoded known symbol based on the previously decoded known symbol.
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41. Receiving apparatus for demodulating and decoding information symbols that include at least one known symbol positioned next to at least two adjacent unknown arbitrary information symbols, wherein the information symbols are grouped in a first group that are coded and modulated on to a radio signal in a first manner and a second group that are coded and modulated in a second manner, comprising:
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a means for receiving said radio signal; means for converting said received radio signal into a suitable form for sampling; means for sampling said converted radio signal and converting samples into numerical values related to instantaneous amplitude and values related to instantaneous phase; means for processing said numerical values to demodulate and decode them and to produce decoded symbols corresponding to information symbols coded and modulated in said first manner, wherein the one unknown arbitrary information symbol, which is next to said known symbol in the first group, is decoded first to generate a decoded known symbol, and the other adjacent arbitrary information symbol, which is not next to said known symbol, is decoded next to generate another decoded known symbol based on the previously decoded known symbol; and means for processing said decoded symbols and said numerical values to produce symbols corresponding to information symbols coded and modulated in said second manner, wherein the one unknown arbitrary information symbol, which is next to said known symbol in second first group, is decoded first to generate a decoded known symbol, and the other adjacent arbitrary information symbol, which is not next to said known symbol, is decoded next to generate another decoded known symbol based on the previously decoded known symbol. - View Dependent Claims (42)
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43. A receiving apparatus for demodulating and decoding information symbols that include at least one known symbol positioned next to at least two adjacent unknown arbitrary information symbols, wherein the information symbols are grouped in a first group that are coded and modulated on to a radio signal in a first manner and a second group that are coded and modulated in a second manner, comprising:
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means for receiving said radio signal; means for converting said received radio signal into a suitable form for sampling; means for sampling said converted radio signal and converting said samples into complex numerical values; means for processing said complex numerical values to demodulate and decode them and to produce decoded symbols corresponding to information symbols coded and modulated in said first manner, wherein the one unknown arbitrary information symbol, which is next to said known symbol in the first group, is decoded first to generate a decoded known symbol, and the other adjacent arbitrary information symbol, which is not next to said known symbol, is decoded next to generate another decoded known symbol based on the previously decoded known symbol; and means for processing said decoded symbols and said numerical values to produce symbols corresponding to information symbols coded and modulated in said second manner, wherein the one unknown arbitrary information symbol, which is next to said known symbol in second first group, is decoded first to generate a decoded known symbol, and the other adjacent arbitrary information symbol, which is not next to said known symbol, is decoded next to generate another decoded known symbol based on the previously decoded known symbol.
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Specification