A study of a suboptimal VLSI architecture for joint source-channel trellis coding

An architectural study of a Joint Source-Channel Trellis Coding (JSCTC) technique is presented. The use of a sub-optimal trellis search algorithm, the M algorithm, is proposed to encode the source in order to keep the encoding complexity independent of the trellis constraint length (i.e. the codebook size). The idea is to increase the codebook size (and thus, the quality of the transmission) without increasing the hardware complexity. A comparison in terms of complexity versus performance between the M algorithm and the optimal search algorithm (Viterbi) is presented for the encoding of a first-order Gauss-Markov source. In addition, the JSCTC system is compared with a conventional communication system consisting of a JPEG codec and a turbo-codec