HYBRID AND CONCATENATED CODING APPLICATIONS

Abstract

This paper presents some of the results of a study to evaluate the performance and implementation complexity of a concatenated and a hybrid coding system for moderate speed deep space applications. It is shown that with a total complexity of less than three times that of the basic Viterbi decoder, concatenated coding improves a constraint length 8 rate 1/3 Viterbi decoding system by 1.1 and 2.6 dB at bit error probabilities of 10^-4 and 10^-8, respectively. With a somewhat greater total complexity, the hybrid coding system is shown to obtain a 0.9 dB computational performance improvement over the basic rate 1/3 sequential decoding system. Although substantial, these complexities are much less than those required to achieve the same performances with more complex Viterbi or sequential decoder systems.