System and method for decoding CDMA quality channel
원문보기
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
H04N-007/167
H04N-007/12
H04N-011/02
H04N-011/04
H04K-001/00
G10L-021/04
G06F-007/00
G06F-015/00
출원번호
UP-0697309
(2003-10-31)
등록번호
US-7649994
(2010-02-22)
발명자
/ 주소
Legnain, Abdelgader
Chen, Xixian
출원인 / 주소
Nortel Networks Limited
인용정보
피인용 횟수 :
0인용 특허 :
12
초록▼
A method of decoding symbols in which a first codeword has been spread by a second codeword to recover first information and second information is provided. The decoding occurs jointly, with an overall output determining both the first and second information. A first parallel code multiplying operat
A method of decoding symbols in which a first codeword has been spread by a second codeword to recover first information and second information is provided. The decoding occurs jointly, with an overall output determining both the first and second information. A first parallel code multiplying operation for each codeword of the second code is followed by a second parallel code multiplying operation for the first code. An overall maximum output of the second parallel code multiplying operations determines the output information.
대표청구항▼
We claim: 1. A method in a wireless receiver of decoding M×N symbols in which a first codeword of length N of a first set of K codewords has been spread by a second codeword of length M of a second set of L codewords, the first codeword identifying a first information and the second codeword i
We claim: 1. A method in a wireless receiver of decoding M×N symbols in which a first codeword of length N of a first set of K codewords has been spread by a second codeword of length M of a second set of L codewords, the first codeword identifying a first information and the second codeword identifying a second information, the method comprising: receiving the M×N symbols via an air interface of the wireless receiver; for each set of M consecutive symbols, performing a first parallel code multiplying operation by multiplying the M symbols by each of the L codewords of the second set of codewords, thereby producing L first output symbols, each of the L first output symbols being associated with one of the L codewords; for each of at least one codeword of said set of L codewords: for a set of N consecutive first output symbols associated with the codeword, performing a respective second parallel code multiplying operation by multiplying the set of N consecutive first output symbols by each of the K codewords of the first set of codewords to produce a set of K second output symbols, each second output symbol being associated with one of the K codewords and with said codeword of the set of said L codewords; determining an overall maximum second output symbol of the second output symbols produced by said second parallel code multiplying operation; and determining the first information from the codeword of the first set of codewords associated with the overall maximum second output symbol and determining the second information from the codeword of the second set of codewords associated with the overall maximum second output symbol. 2. A method according to claim 1 wherein the first set of codewords is a Walsh code, and the second parallel code multiplying operation comprises a FHT (Fast Hadamard Transform). 3. A method according to claim 2 wherein M=8, N=8, L=8, K=8 the first set of codewords is an 8-Walsh code, and the second set of codewords is an 8-Walsh code. 4. A method according to claim 3 wherein the first information comprises a data rate control indication, and wherein the second information comprises a sector identifier. 5. A method according to claim 1 wherein the first set of codewords is a truncated Walsh code, the method further comprising padding each set of N consecutive output symbols to a power of 2, wherein the second parallel code multiplying operation comprises a FHT. 6. A method according to claim 5 wherein the second set of codewords is a Walsh code, and the first parallel code multiplying operation comprises a FHT. 7. A method according to claim 6 wherein M=8, N=12, L=8, K=16, the second set of codewords is an 8-Walsh code, and wherein the first set of codewords is a truncated Walsh code in the form of a (12,4) block code which is padded to length 16. 8. A method according to claim 7 wherein the first information comprises a channel quality indication, and wherein the second information comprises a sector identifier. 9. A method according to claim 1 wherein the second set of codewords is a Walsh code, and the first parallel code multiplying operation comprises a FHT. 10. A method according to claim 1 wherein the second set of codewords is an orthogonal code. 11. A method according to claim 1 further comprising: performing sequence de-repetition prior to said first parallel code multiplying operation. 12. A method according to claim 1 wherein said second parallel code multiplying operation is performed for at least 2 of the L codewords. 13. A method according to claim 1 wherein said second parallel code multiplying operation is performed for all of the L codewords. 14. A method according to claim 1 wherein said at least one codeword are fewer than all of the L codewords, and the at least one codeword is selected by accumulating energy after the first parallel code multiplying operation for each possible codeword after the first parallel code multiplying operation, and selecting the at least one codeword having greatest energy. 15. An apparatus for decoding M×N symbols in which a first codeword of length N of a first set of K codewords has been spread by a second codeword of length M of a second set of L codewords, the first codeword identifying a first information and the second codeword identifying a second information, the apparatus comprising: a wireless receiver configured to receive the M×N symbols wirelessly; a first parallel code multiplier which, for each set of M consecutive symbols, performs a first parallel code multiplying operation by multiplying the M symbols by each of the L codewords of the second set of codewords, thereby producing L first output symbols, each of the L first output symbols being associated with one of the L codewords; a second parallel code multiplier which, for each of at least one codeword of said set of L codewords, performs: for a set of N consecutive first output symbols associated with the codeword, a respective second parallel code multiplying operation by multiplying the set of N consecutive first output symbols by each of the K codewords of the first set of codewords to produce a set of K second output symbols, each second output symbol being associated with one of the K codewords and with said codeword of the set of said L codewords; wherein an overall maximum second output symbol of the second output symbols produced by said second parallel code multiplying operations is selected, the first information is determined from the codeword of the first set of codewords associated with the overall maximum second output symbol and the second information is determined from the codeword of the second set of codewords associated with the overall maximum second output symbol. 16. An apparatus according to claim 15 wherein the first set of codewords is a Walsh code, and the second parallel code multiplying operation comprises a FHT (fast Hadamard transform). 17. An apparatus according to claim 16 wherein M=8, N=8, L=8, K=8 the first set of codewords is an 8-Walsh code, and the second set of codewords is an 8-Walsh code. 18. An apparatus according to claim 15 wherein the first set of codewords is a truncated Walsh code, the apparatus being further adapted to pad each set of N consecutive output symbols to a power of 2, wherein the second parallel code multiplier comprises a FHT. 19. An apparatus according to claim 18 wherein the second set of codewords is a Walsh code, and the first parallel code multiplier comprises a FHT. 20. An apparatus according to claim 19 wherein M=8, N=12, L=8, K=16, the second set of codewords is an 8-Walsh code, and wherein the first set of codewords is a truncated Walsh code in the form of a (12,4) block code which is padded to length 16. 21. An apparatus according to claim 15 wherein the second set of codewords is a Walsh code, and the first parallel code multiplier comprises a FHT. 22. An apparatus according to claim 15 wherein the second set of codewords is an orthogonal code. 23. An apparatus according to claim 15 further comprising: a sequence de-repetition function adapted to perform sequence de-repetition prior to said first parallel code multiplier. 24. An apparatus according to claim 15 wherein the first information comprises a channel quality indication, and wherein the second information comprises a sector identifier. 25. An apparatus according to claim 15 wherein the first information comprises a data rate control indication, and wherein the second information comprises a sector identifier. 26. An apparatus according to claim 15 wherein the second parallel code multiplying operation is performed for at least 2 of the L codewords. 27. An apparatus according to claim 15 wherein the second parallel code multiplying operation is performed for all of the L codewords. 28. An apparatus according to claim 15 wherein said at least one codeword are fewer than all of the L codewords, and the at least one codeword is selected by accumulating energy for each possible codeword after the first parallel code multiplying operation, and selecting the at least one codeword having greatest energy.
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이 특허에 인용된 특허 (12)
Harrison Robert M. (Grapevine TX) Schaffner Terry M. (Palatine IL), Apparatus and method for digitally processing signals in a radio frequency communication system.
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Blakeney ; II Robert D. (San Diego CA) Karmi Gadi (San Diego CA) Tiedemann ; Jr. Edward G. (San Diego CA) Weaver ; Jr. Lindsay A. (San Diego CA), Mobile station assisted soft handoff in a CDMA cellular communications system.
Gilhousen Klein S. (San Diego CA) Jacobs Irwin M. (La Jolla CA) Padovani Roberto (San Diego CA) Weaver ; Jr. Lindsay A. (San Diego CA) Wheatley ; III Charles E. (Del Mar CA) Viterbi Andrew J. (La Jol, System and method for generating signal waveforms in a CDMA cellular telephone system.
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