| 摘要 |
PURPOSE: To provide a Viterbi detector for a channel having memory length '1' by extracting a new difference distance from the combination of a saturation function of the previous difference distance and a correction signal, i.e., a scale used for a channel variable difference. CONSTITUTION: The output of a memory 14 is connected to the 1st input of a function generator 18, and a detection signal (rk) is supplied to the 2nd input of the generator 18. The output of the generator 18 which carries a signal S(▵) is connected to the 1st input of an addition circuit 12, and a correction signal CK is supplied to the 2nd input of the circuit 12. The output of the circuit 12 is connected to the input of the memory 14. A difference distance▵K is stored in the memory 14, and the generator 18 extracts an expression signal S (▵K) from the value storing the difference▵K and signal (rk). The circuit 12 combines the output signal of the generator 18 with the signal CK, i.e., a scale used for the difference between a channel variable set at the current time point and an expected channel variable. The logical value of signals m<+> , m<o> and m<-> are decided in an area where a signal▵K, or S(▵K) exists.
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