Processing unit and processing method
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsRyutaro Yamanaka, Hidetoshi Suzuki, Hideyuki Kabuo, Minoru Okamoto, Kevin Mark Stone
Life of this patent
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Abstract
A method of operating a digital signal processor is provided. The digital signal processor may be provided as a radio communication mobile station, a radio communication base station apparatus, or a CDMA radio communication system. Each path metric PM1 and PM0 of an old state is added to each branch metric BM1 and BM0 separately. A path metric of a new state N is formed by comparing the value of PM1+BM1 to the value of PM0+BM0. A path metric of a new state N+2k−2 is formed by comparing the value of PM1+BM0 to PM0+BM1.
Claims13
A method of operating a digital signal processor capable of performing a Viterbi algorithm comprising:
- calculating a sum of path metric PM1 of an old state 2N and branch metric BM1, where N=0, 1, . . . 2k−2−1, and K represents a constraining length;
- calculating a sum of path metric PM0 of an old state 2N+1 and branch metric BM0;
- calculating a sum of the path metric PM1 and the branch metric BM0;
- calculating a sum of the path metric PM0 and the branch metric BM1;
- and
- comparing the value of PM1+BM1 to the value of PM0+BM0 to form a path metric of a new state N, and comparing the value of PM1+BM0 to the value of PM0+BM1 to form a path metric of a new state N+2K−2.
A digital signal processor capable of performing a Viterbi algorithm comprising:
- an instruction fetching system that fetches instructions;
- a decoding system that decodes the instructions fetched by the instruction fetching system;
- and
- an executing system that executes the instructions decoded by the decoding system, the executing system comprising:
- a first comparing system that compares a first data that includes a sum of a path metric PM1 of an old state 2N and a branch metric BM1 with a second data that includes a sum of a path metric PM0 of an old state 2N+1 and a branch metric BM0;
- and
- a second comparing system that compares a third data that includes a sum of the path metric PM 1 and branch metric BM0 with a fourth data that includes a sum of the path metric PM0 and the branch metric BM1, where N=0, 1, . . . , 2K−2−1, and where K represents a constraint length, wherein the first comparing system and the second comparing system operate together.
Dependencies are inferred from the claim text.