| 摘要 |
PROBLEM TO BE SOLVED: To provide improved branch metric expression on the basis of a linear distance. SOLUTION: This decoder 10 decoding a received symbol sequence has a branch metric calculation(BMC) unit 12, an addition comparison selection(ACS) unit 14 and a trace back unit 16. The unit 12 calculates a branch metric related to transition between multistage trellis representation states of a state machine. Each branch metric corresponds to a linear distance between a given received symbol and its most adjacent code word in a given trellis stage. The unit 14 utilizes a branch metric on the current stage together with a previously generated path metric for comparison in the case of finding a survival path to the current stage of a multistage trellis and a corresponding update path metric. The unit 16 utilizes the update path metric and generates a corresponding decoded output. |
