VITERBI DECODER AND VITERBI DECODING METHOD

摘要

PROBLEM TO BE SOLVED: To constitute a path memory with a normal RAM and to reduce the circuit scale and power consumption as Viterbi decoding for decoding trellis encoded modulated signals. SOLUTION: A trace-back part 107 traces back path selection signals PS0-PS7 stored in a trace-back memory 106 for a prescribed length. A sub set number generation part 108 uses the number ND1 of a node for passing through a maximum likelihood path obtained by trace-back and outputs an encoding bit CB and a sub set number SSNO relating to transition to the node corresponding to a trellis diagram. A selection circuit 109 selectively outputs a non- encoding bit NCB relating to the transition to the node corresponding to the sub set number SSNO.