| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain the valid decoding bit by discriminating effectively signals at plural rates without revision of the specification at the transmitter side. SOLUTION: A metric value of a received signal is obtained sequentially by ACS circuits 10, 12,...1N at different trelis trace rates, the path metrics of the result of sum are compared and the most probable path is selected. Furthermore, M truncation circuit 30 compares the paths and an unexpected path is truncated. The pathmetric of the expected paths is sequentially stored in metric memories 20, 22,...2N and again fed to the ACS circuits 10, 12,...1N, in which the trelis tracing is executed. After the repetition above, the M truncation circuit 30 selects M-sets of paths (M<N) among the paths from the N-sets of the ACS circuits and gives the selected paths to a discrimination circuit 50 and survival paths are stored in path memories 40, 42,...4N. The discrimination 50 selects a minimum path metric among the M-sets of path metric values and reads and traces back the path from the path memories 40, 42,...4N for decoding.</p> |
