SEQUENTIAL-DECODING OF CONVOLUTIONAL-CODES IN CHANNELS WITH INTERSYMBOL INTERFERENCE

Sequential sequence estimation for communications channels with convol utionally coded input sequences and intersymbol interference (ISI) is proposed. The receiver consists of a whitened matched filter (WMF) and a vector sequential decoder. The metric of the vector sequential algo rithm (SA) is derived. Analytical results for error probability and co mputational complexity of the sequential decoder are presented. The er ror probability is found to be dominated by the minimum Euclidean dist ance between the possible output sequences and the computational distr ibution is Pareto, typical of a sequential decoder. The computational cut-off code rate R(comp) and its lower bound R(comp)' are also derive d. Numerical simulation results of the error probability and the compu tational complexity are presented. Comparing with the Viterbi algorith m (VA) reveals that the SA essentially has the same error performance as that of the VA while its average computational complexity is one to two orders of magnitude less than that of the VA.