Simulation Study of the Performance of the Viterbi Decoding Algorithm for Certain M-Level Line Codes

In this paper we study the performance of different classes of M-level line codes under the Viterbi decoding algorithm. Some of the presented M-level line codes inherited the state machine structure by using the technique of distance mappings which preserve the properties of binary convolutional codes. Other M-level line codes were enforced to have the state machine structure to make use of the Viterbi decoding algorithm. The technique of spectral shaping was combined with distance mappings to generate spectral null distance mappings (SNDM) M-level line codes. The 2-dB gain between soft and hard decisions decoding for the different classes of M-level line codes is investigated. The standard technique for assessing the stability and the accuracy of any decoding algorithm, which is the error propagation is used to analyze the stability and the accuracy of the Viterbi decoding algorithm of the M-level line codes. The obtained results have shown advantages and outperformance of SNDM codes compared to the rest of line codes presented in this paper.