USRE45230EExpiredUtility

Wireless communication system having linear encoder

88
Assignee: UNIV MINNESOTAPriority: Apr 22, 2002Filed: Apr 8, 2013Granted: Nov 4, 2014
Est. expiryApr 22, 2022(expired)· nominal 20-yr term from priority
H04L 27/2602H04L 5/0044H04L 2025/03414H04L 2025/0349H04L 5/0007H04L 1/0041H04L 1/04
88
PatentIndex Score
12
Cited by
208
References
77
Claims

Abstract

In general, linear complex-field encoding techniques are proposed. For example, transmitter of a wireless communication system includes an encoder and a modulator. The encoder linearly encodes a data stream to produce an encoded data stream. The modulator to produce an output waveform in accordance with the encoded data stream for transmission through a wireless channel. The modulator generates the output waveform as a multicarrier waveform having a set of subcarriers, e.g., an Orthogonal Frequency Division Multiplexing (OFDM) waveform. The encoder linearly encodes the data stream so that the subcarriers carry different linear combinations of information symbols of the data stream.

Claims

exact text as granted — not AI-modified
The invention claimed is: 
     
       1. A wireless communication device comprising:
 a first encoder that encodes a data stream based on an error-control code to produce encoded symbols; 
 an interleaver that interleaves the encoded symbols to produce interleaved symbols; 
 a constellation mapper that maps the interleaved symbols to produce a stream of information bearing symbols selected from a constellation having a finite alphabet; 
 ana second encoder that applies a linear transformation to athe stream of information bearing symbols selected from athe constellation having athe finite alphabet to produce a stream of precoded symbols that are complex numbers and that are not restricted by the constellation of the information bearing symbols; and 
 a modulator to produce an output waveform in accordance with the stream of precoded symbols for transmission through a wireless channel. 
 
     
     
       2. The wireless communication device of  claim 1 , wherein the modulator generates the output waveform as a multicarrier waveform having a set of subcarriers, and the second encoder encodes the stream of information bearing symbols so that the subcarriers carry different linear combinations of the information symbols. 
     
     
       3. The wireless communication device of  claim 1 , wherein the second encoder applies the linear transformation by applying a unitary matrix to the information bearing symbols. 
     
     
       4. A wireless communication device comprising:
 a first encoder that encodes a data stream based on an error-control code to produce encoded symbols; 
 an interleaver that interleaves the encoded symbols to produce interleaved symbols; 
 a constellation mapper that maps the interleaved symbols to produce blocks of K information bearing symbols selected from a constellation having a finite alphabet; 
 ana second encoder that applies a matrix to linearly transform the blocks of K information bearing symbols selected from athe constellation having athe finite alphabet to produce blocks of N precoded symbols that are complex numbers and that are not restricted to the constellation of the information bearing symbols; and 
 a modulator that generates a multicarrier waveform having a set of subcarriers, where N is the number of subcarriers of the multi-carrier multicarrier waveform and K is less than or equal to N. 
 
     
     
       5. The wireless communication device of  claim 4 , wherein the linear second encoder has a code rate r=K/N. 
     
     
       6. The wireless communication device of  claim 4 , wherein the linear second encoder applies a matrix of size N×K to the blocks of K information bearing symbols to produce the blocks of N precoded symbols. 
     
     
       7. A wireless communication device, comprising:
 an encoder that applies a matrix to linearly transform blocks of K information bearing symbols selected from a constellation having a finite alphabet to produce blocks of N precoded symbols that are complex numbers and that are not restricted by the constellation of the information bearing symbols; and 
 a modulator that generates a multicarrier waveform having a set of subcarriers for transmission over a wireless channel, wherein N is the number of subcarriers and K is less than or equal to N, and wherein the size of the matrix is selected as a function of an order L of the wireless channel, and the number K of symbols per block is selected as a function of the channel order L. 
 
     
     
       8. The wireless communication device of  claim 7 , wherein K is selected so that K≧N−L. 
     
     
       9. The wireless communication device of  claim 7 , wherein K is selected so that K=N−L. 
     
     
       10. The wireless communication device of claim  6  7, wherein the linear encoder applies the matrix to perform a vector multiplication on the blocks of K information bearing symbols to produce the blocks of N precoded symbols, and applies each block of N precoded symbols across the N subcarriers. 
     
     
       11. The wireless communication device of  claim 1 , wherein the wireless communication device comprises one of a base station and a mobile device. 
     
     
       12. A wireless communication device comprising:
 an encoder that applies a plurality of M matrices to linearly transform a stream of information bearing symbols selected from a constellation having a finite alphabet to produce a stream of precoded symbols that are complex numbers and that are not restricted by the constellation of the information bearing symbols; and 
 a modulator to produce that produces an output waveform in accordance with the stream of precoded symbols for transmission through a wireless channel, where the matrices are identical and collectively have M*L redundant rows, where L represents an order of the wireless channel. 
 
     
     
       13. A wireless communication device comprising:
 a demodulator that receives a waveform carrying a encoded transmission and that produces a demodulated data stream, the encoded transmission including an encoded data stream, wherein the encoded data stream was produced by performing error-control coding on an input stream to produce coded symbols, interleaving the coded symbols to produce interleaved symbols, mapping the interleaved symbols to produce a stream of information bearing symbols selected from a constellation having a finite alphabet, and applying a linear transformation to a the stream of information bearing symbols selected from a the constellation having a the finite alphabet to produce a stream of precoded symbols that are complex numbers and that are not restricted by the constellation of the information bearing symbols; and 
 a decoder that decodes the demodulated data stream to produce estimated data. 
 
     
     
       14. The wireless communication device of  claim 13 , wherein the decoder applies one of maximum-likelihood detection, zero-force (ZF) detection, minimum mean squared error (MMSE) detection, decision-directed detection, iterative detection, to decode the demodulated data stream. 
     
     
       15. The wireless communication device of  claim 13 , wherein the wireless communication device comprises one of a base station and a mobile device. 
     
     
       16. A method comprising:
 performing error-control coding on an input stream to produce coded symbols; 
 interleaving the coded symbols to produce interleaved symbols; 
 mapping the interleaved symbols to produce a stream of information bearing symbols selected from a constellation having a finite alphabet; 
 applying a linear transformation to a the stream of information bearing symbols selected from a the constellation having a the finite alphabet to produce a stream of precoded symbols that are complex numbers and that are not restricted by the constellation of the information bearing symbols; and 
 outputting a waveform in accordance with the stream of precoded symbols for transmission through a wireless channel. 
 
     
     
       17. The method of  claim 16 , wherein outputting the waveform comprises:
 outputting the output waveform as a multicarrier waveform having a set of subcarriers; and 
 encoding the stream of information bearing symbols so that the subcarriers carry different linear combinations of information symbols. 
 
     
     
       18. The method of  claim 16 , wherein applying the linear transformation to the stream of information bearing symbols comprises applying a unitary matrix to the stream of information bearing symbols. 
     
     
       19. A method comprising:
 performing error-control coding on an input stream to produce coded symbols; 
 interleaving the coded symbols to produce interleaved symbols; 
 mapping the interleaved symbols to produce blocks of K information bearing symbols selected from a constellation having a finite alphabet; 
 applying a matrix to linearly transform the blocks of K information bearing symbols that are selected from a the constellation having a the finite alphabet to produce blocks of N precoded symbols that are complex numbers and that are not restricted by the constellation of the information bearing symbols, and 
 outputting a multicarrier waveform having a set of subcarriers in accordance with the stream of blocks of N precoded symbols for transmission through a wireless channel, where N is the number of subcarriers, and K is less than or equal to N. 
 
     
     
       20. The method of  claim 19 , wherein applying the linear transformation matrix comprises applying the linear transformation a matrix of size N×K to the blocks of K information bearing symbols to produce blocks of N precoded symbols at a code rate r=K/N. 
     
     
       21. The method of  claim 19 , wherein applying the linear transformation matrix comprises applying a unitary matrix of size N×K to the blocks of K information bearing symbols, wherein K is equal to N. 
     
     
       22. The method of  claim 19 , further comprising selecting the number of symbols per block K as a function of an order of the channel. 
     
     
       23. The method of  claim 19 , further comprising selecting the number of symbols per block K so that K≧N−L, wherein L represents an order of the channel. 
     
     
       24. The method of  claim 19 , further comprising selecting the number of symbols per block K so that K=N−L, where L represents an order of the channel. 
     
     
       25. The method of  claim 19 , wherein applying the linear transformation matrix comprises applying a matrix to perform a vector multiplication on the blocks of K information bearing symbols to produce the blocks of N precoded symbols. 
     
     
       26. A method comprising:
 applying a plurality of M matrices to linearly transform a stream of information bearing symbols selected from a constellation having a finite alphabet, wherein the M matrices linearly transform the stream of information bearing symbols to produce a stream of precoded symbols that are complex numbers and that are not restricted by the constellation of the information bearing symbols; and 
 outputting a waveform in accordance with the stream of precoded symbols for transmission through a wireless channel, where the matrices are identical and have M*L redundant rows and, where L represents an order of the channel. 
 
     
     
       27. A non-transitory computer-readable medium comprising instructions to cause a programmable processor to:
 perform error-control coding on an input stream to produce coded symbols; 
 interleave the coded symbols to produce interleaved symbols; 
 map the interleaved symbols to produce a stream of information bearing symbols selected from a constellation having a finite alphabet; 
 apply a linear transformation to a stream of information bearing symbols selected from a the constellation having a the finite alphabet to produce a stream of precoded symbols that are complex numbers and are not restricted by the constellation of the information bearing symbols; and 
 output waveform in accordance with the stream of precoded symbols for transmission through a wireless channel. 
 
     
     
       28. The non-transitory computer-readable medium of  claim 27 , further comprising instructions to cause the programmable processor to:
 output the output waveform as a multicarrier waveform having a set of subcarriers; and 
 encode the stream of information bearing symbols so that the subcarriers carry different linear combinations of information symbols. 
 
     
     
       29. The wireless communication device of claim 1, wherein the output waveform comprises multiple output waveforms for transmission on multiple antennas, respectively. 
     
     
       30. The wireless communication device of claim 29, wherein the linear transformation is based on multiple matrices comprising a first matrix and a second matrix, wherein the first matrix is based on a fast Fourier transform (FFT) matrix, and wherein the second matrix is based on a diagonal matrix to phase-rotate each entry of a symbol vector. 
     
     
       31. The wireless communication device of claim 30, wherein the number of the antennas is represented by N t , wherein the first matrix is based on an N t -point inverse version of the FFT matrix, wherein the linear transformation is based on: 
       
         
           
             
               
                 Θ 
                 = 
                 
                   
                     F 
                     
                       N 
                       t 
                     
                     T 
                   
                   ⁢ 
                   
                     diag 
                     ⁡ 
                     
                       ( 
                       
                         1 
                         , 
                         α 
                         , 
                         … 
                         ⁢ 
                         
                             
                         
                         , 
                         
                           α 
                           
                             
                               N 
                               t 
                             
                             - 
                             1 
                           
                         
                       
                       ) 
                     
                   
                 
               
               , 
               
                 α 
                 := 
                 
                   ⅇ 
                   
                     j 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     2 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     
                       π 
                       / 
                       P 
                     
                   
                 
               
             
           
         
       
       wherein F N     t     T  represents the first matrix, and wherein
 diag(1, α, . . . , α N     t     −1 ) 
 
       represents the second matrix, wherein P is an integer. 
     
     
       32. The wireless communication device of claim 29, wherein the number of the antennas is represented by N t , and wherein the linear transformation is based on a Vandermonde matrix of size N t ×N t . 
     
     
       33. The wireless communication device of claim 29, wherein the number of the antennas is represented by N t , wherein the linear transformation is based on multiple matrices comprising a first matrix and a second matrix,
 wherein the first matrix is a matrix of size N t ×N t , wherein each entry of the first matrix is based on a power of e j2π/N     t   , each entry of a column of the first matrix being equal to one, and   wherein the second matrix is a diagonal matrix of size N t ×N t  having diagonal entries that are based respectively on different powers of e j2π/P  including the zeroth power, wherein P is an integer.   
     
     
       34. The wireless communication device of claim 33, wherein the multiple matrices include a third matrix, wherein the third matrix is a matrix of size N t ×N t . 
     
     
       35. The wireless communication device of claim 1, wherein the output waveform comprises an orthogonal frequency division multiplexing (OFDM) waveform. 
     
     
       36. The method of claim 16, wherein interleaving the coded symbols to produce the interleaved symbols comprises writing the coded symbols into a matrix row-wise, and reading the encoded symbols from the matrix column-wise. 
     
     
       37. The method of claim 16, wherein performing the error-control coding on the input stream comprises applying at least one of a turbo code and a convolutional code, wherein the constellation having the finite alphabet is a quadrature amplitude modulation (QAM) constellation, and wherein mapping the interleaved symbols comprises selecting symbols from the QAM constellation as the information bearing symbols. 
     
     
       38. The method of claim 16, wherein applying the linear transformation comprises applying the linear transformation to the stream of information bearing symbols to produce the stream of precoded symbols such that the stream of precoded symbols differs, at least in part, from the stream of information bearing symbols, wherein the stream of precoded symbols includes complex numbers. 
     
     
       39. The method of claim 16, wherein outputting the waveform comprises outputting multiple waveforms via multiple antennas, respectively. 
     
     
       40. The method of claim 39, wherein the linear transformation is based on multiple matrices comprising a first matrix and a second matrix, wherein the first matrix is based on a fast Fourier transform (FFT) matrix, and wherein the second matrix is based on a diagonal matrix to phase-rotate each entry of a symbol vector. 
     
     
       41. The method of claim 40, wherein the number of the antennas is represented by N t , wherein the first matrix is based on an N t -point inverse version of the FFT matrix, wherein the linear transformation is based on: 
       
         
           
             
               
                 Θ 
                 = 
                 
                   
                     F 
                     
                       N 
                       t 
                     
                     T 
                   
                   ⁢ 
                   
                     diag 
                     ⁡ 
                     
                       ( 
                       
                         1 
                         , 
                         α 
                         , 
                         … 
                         ⁢ 
                         
                             
                         
                         , 
                         
                           α 
                           
                             
                               N 
                               t 
                             
                             - 
                             1 
                           
                         
                       
                       ) 
                     
                   
                 
               
               , 
               
                 α 
                 := 
                 
                   ⅇ 
                   
                     j 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     2 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     
                       π 
                       / 
                       P 
                     
                   
                 
               
             
           
         
       
       wherein F N     t     T  represents the first matrix, and wherein
 diag(1, α, . . . , α N     t     −1 ) 
 
       represents the second matrix, wherein P is an integer. 
     
     
       42. The method of claim 39, wherein the number of the antennas is represented by N t , and wherein the linear transformation is based on a Vandermonde matrix of size N t ×N t . 
     
     
       43. The method of claim 39, wherein the number of the antennas is represented by N t , wherein the linear transformation is based on multiple matrices comprising a first matrix and a second matrix,
 wherein the first matrix is a matrix of size N t ×N t , wherein each entry of the first matrix is based on a power of e j2π/N     t   , each entry of a column of the first matrix being equal to one, and   wherein the second matrix is a diagonal matrix of size N t ×N t  having diagonal entries that are based respectively on different powers of e j2π/P  including the zeroth power, wherein P is an integer.   
     
     
       44. The method of claim 43, wherein the multiple matrices include a third matrix, wherein the third matrix is a matrix of size N t ×N t . 
     
     
       45. The method of claim 16, wherein outputting the waveform comprises outputting an orthogonal frequency division multiplexing (OFDM) waveform. 
     
     
       46. The method of claim 18, wherein applying the unitary matrix comprises applying a unitary matrix of size M×M in which all entries have equal norm of 1/√{square root over (M)}, where M is an integer greater than one. 
     
     
       47. The method of claim 19, wherein outputting the multicarrier waveform comprises outputting multiple waveforms via multiple antennas, respectively. 
     
     
       48. The method of claim 19, wherein outputting the multicarrier waveform comprises outputting an orthogonal frequency division multiplexing (OFDM) waveform. 
     
     
       49. A method comprising:
 applying a linear transformation to a stream of information bearing symbols selected from a constellation having a finite alphabet to produce a stream of precoded symbols that are complex numbers and that are not restricted by the constellation of the information bearing symbols; and   outputting a waveform in accordance with the stream of precoded symbols for transmission through a wireless channel,   wherein the method further comprises:
 performing error-control coding on an input data stream to produce coded bits; 
 interleaving the coded bits to produce interleaved bits; 
 mapping groups of the interleaved bits to produce the stream of information bearing symbols selected from the constellation having the finite alphabet, wherein a size of the constellation is larger than two, and wherein interleaving the coded bits comprises separating the coded bits so that neighboring coded bits are mapped to different information bearing symbols. 
   
     
     
       50. The method of claim 49, wherein interleaving the coded bits to produce the interleaved bits comprises writing the coded bits into a matrix row-wise, and reading the coded bits from the matrix column-wise. 
     
     
       51. The method of claim 49, wherein interleaving the coded bits to produce the interleaved bits comprises positioning the coded bits to be mapped to different blocks of information bearing symbols. 
     
     
       52. The method of claim 49, wherein performing the error-control coding on the input stream comprises applying a turbo code. 
     
     
       53. The method of claim 49, wherein performing the error-control coding on the input stream comprises applying a convolutional code. 
     
     
       54. The method of claim 49, wherein the constellation having the finite alphabet is based on quadrature amplitude modulation (QAM). 
     
     
       55. The method of claim 49, wherein the constellation having the finite alphabet is based on quadrature phase shift keying (QPSK). 
     
     
       56. The method of claim 49, wherein applying the linear transformation comprises applying a unitary matrix of size M×M in which all entries have equal norm of 1/√{square root over (M)}, where M is an integer greater than one. 
     
     
       57. The method of claim 49, wherein outputting the waveform comprises outputting multiple waveforms via multiple antennas, respectively. 
     
     
       58. The method of claim 49, wherein outputting the waveform comprises outputting an orthogonal frequency division multiplexing (OFDM) waveform. 
     
     
       59. A wireless communication device comprising:
 an encoder that applies a linear transformation to a stream of information bearing symbols selected from a constellation having a finite alphabet to produce a stream of precoded symbols that are complex numbers and that are not restricted by the constellation of the information bearing symbols;   a modulator that produces an output waveform in accordance with the stream of precoded symbols for transmission through a wireless channel; and   circuitry configured to (i) perform error-control coding on an input stream to produce coded bits, (ii) interleave the coded bits to produce blocks of interleaved bits, and (iii) map the blocks of interleaved bits to produce the stream of information bearing symbols selected from the constellation having the finite alphabet.   
     
     
       60. The wireless communication device of claim 59, wherein a size of the constellation is larger than two, and wherein the circuitry is configured to separate the coded bits so that neighboring coded bits are mapped to different information bearing symbols. 
     
     
       61. The wireless communication device of claim 59, wherein the wireless communication device comprises one of a base station and a mobile device. 
     
     
       62. The wireless communication device of claim 59, wherein the output waveform comprises multiple output waveforms for transmission on multiple antennas, respectively. 
     
     
       63. The wireless communication device of claim 59, wherein the output waveform comprises an orthogonal frequency division multiplexing (OFDM) waveform. 
     
     
       64. A method comprising:
 applying a linear transformation to a stream of information bearing symbols selected from a constellation having a finite alphabet to produce a stream of precoded symbols that are complex numbers and that are not restricted by the constellation of the information bearing symbols; and   outputting, via multiple antennas, waveforms in accordance with the stream of precoded symbols for transmission through a wireless channel,   wherein the linear transformation is based on multiple matrices comprising a first matrix and a second matrix, wherein the first matrix is based on a fast Fourier transform (FFT) matrix, and wherein the second matrix is based on a diagonal matrix to phase-rotate each entry of a symbol vector.   
     
     
       65. The method of claim 64, wherein the number of the antennas is represented by N t , and wherein the first matrix is based on an N t -point inverse version of the FFT matrix. 
     
     
       66. The method of claim 65, wherein the linear transformation is based on: 
       
         
           
             
               
                 Θ 
                 = 
                 
                   
                     F 
                     
                       N 
                       t 
                     
                     T 
                   
                   ⁢ 
                   
                     diag 
                     ⁡ 
                     
                       ( 
                       
                         1 
                         , 
                         α 
                         , 
                         … 
                         ⁢ 
                         
                             
                         
                         , 
                         
                           α 
                           
                             
                               N 
                               t 
                             
                             - 
                             1 
                           
                         
                       
                       ) 
                     
                   
                 
               
               , 
               
                 α 
                 := 
                 
                   ⅇ 
                   
                     j 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     2 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     
                       π 
                       / 
                       P 
                     
                   
                 
               
             
           
         
       
       wherein F N     t     T  represents the first matrix, and wherein
 diag(1, α, . . . , α N     t     −1 ) 
 
       represents the second matrix, wherein P is an integer. 
     
     
       67. The method of claim 64, wherein the method further comprises:
 performing error-control coding on an input data stream to produce coded bits;   interleaving the coded bits to produce interleaved bits;   mapping groups of the interleaved bits to produce the stream of information bearing symbols selected from the constellation having the finite alphabet, wherein a size of the constellation is larger than two, and wherein interleaving the coded bits comprises separating the coded bits so that neighboring coded bits are mapped to different information bearing symbols.   
     
     
       68. A device comprising:
 an encoder that applies a linear transformation to a stream of information bearing symbols selected from a constellation having a finite alphabet to produce a stream of precoded symbols that are complex numbers and that are not restricted by the constellation of the information bearing symbols; and   a modulator that produces output waveforms in accordance with the stream of precoded symbols for transmission through a wireless channel via multiple antennas,   wherein the linear transformation is based on multiple matrices comprising a first matrix and a second matrix, wherein the first matrix is based on a fast Fourier transform (FFT) matrix, and wherein the second matrix is based on a diagonal matrix to phase-rotate each entry of a symbol vector.   
     
     
       69. The device of claim 68, wherein the number of the antennas is represented by N t , and wherein the first matrix is based on an N t -point inverse version of the FFT matrix. 
     
     
       70. The device of claim 68, wherein the linear transformation is based on: 
       
         
           
             
               
                 Θ 
                 = 
                 
                   
                     F 
                     
                       N 
                       t 
                     
                     T 
                   
                   ⁢ 
                   
                     diag 
                     ⁡ 
                     
                       ( 
                       
                         1 
                         , 
                         α 
                         , 
                         … 
                         ⁢ 
                         
                             
                         
                         , 
                         
                           α 
                           
                             
                               N 
                               t 
                             
                             - 
                             1 
                           
                         
                       
                       ) 
                     
                   
                 
               
               , 
               
                 α 
                 := 
                 
                   ⅇ 
                   
                     j 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     2 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     
                       π 
                       / 
                       P 
                     
                   
                 
               
             
           
         
       
       wherein F N     t     T  represents the first matrix, and wherein
 diag(1, α, . . . , α N     t     −1 ) 
 
       represents the second matrix, wherein P is an integer. 
     
     
       71. The device of claim 68, further comprising:
 circuitry configured to (i) perform error-control coding on an input stream to produce coded bits, (ii) interleave the coded bits to produce blocks of interleaved bits, and (iii) map the blocks of interleaved bits to produce the stream of information bearing symbols selected from the constellation having the finite alphabet.   
     
     
       72. The device of claim 68, wherein the output waveforms comprises orthogonal frequency division multiplexing (OFDM) waveforms. 
     
     
       73. The wireless communication device of claim 29, wherein the linear transformation is based on a Fourier transform. 
     
     
       74. The wireless communication device of claim 34, wherein the third matrix is a unitary matrix. 
     
     
       75. The method of claim 39, wherein the linear transformation is based on a Fourier transform. 
     
     
       76. The method of claim 44, wherein the third matrix is a unitary matrix. 
     
     
       77. The wireless communication device of claim 13, wherein the linear transformation is based on a Fourier transform.

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