说明：  ％ decode with soft-input viterbi algorithm 硬判决 ％ //k=4,r=1/2 ％输入数据为软信息，并且数据为均值为1的BPSK调制，如果均值为MEAN,那么62,63,103,104行应做相应修改
( Decode with soft-input viterbi algorithm hard-decision// k = 4, r = 1/2 input data for the soft information and data for the average one of BPSK modulation, if the average for the MEAN, then the line should 62,63103104 make consequential amendments to)