Applied of Trellis-Coded Modulation Technique in Underwater Acoustic Communication Based on PDS

The system of PDS(Pattern time Delay Shift) coding communication can resist the multi-path interfere well,but it can not resist noise in the channel well.Integrating TCM(Trellis-Coded Modulation) code and PDS scheme can solve this problem by coding the source information with convolutional code and decoding the received sequence by soft-decision Viterbi algorithm.Experimental results show that the proposed scheme gets about 3 dB coding gain,has better performance over the original decoding scheme.