| 摘要 |
PROBLEM TO BE SOLVED: To simplify the structure of the system and to reduce a time required for decoding by allowing the decoder to support both a 8-state mode and a 16-state mode and using one decoder only in time division in place of 12 decoders of a conventional system. SOLUTION: In the case that received trelis code data indicate the 8-state mode, a segment synchronizing signal elimination filter 1 passes the trelis code data as they are in response to a mode selection signal FENA, and in the case that the received trelis code data indicate the 16-state mode, the segment synchronizing signal elimination filter 1 eliminates the effect of a segment synchronizing signal and provides an output of a symbol to be decoded. A BMU 2 outputs 7 branch metrics BM1-7 in the case of the 8-state mode and outputs 15 branch metrics BM1-15 in the case of the 16-state mode. An ACS 3 receives the mode selection signal FENA and all branch metrics from the BMU 2 and selects a path with a highest probability among many path metrics. |
