Performance of Soft Viterbi Decoder Enhanced with Non-Transmittable Codewords for Storage Media

Abstract

The introduction of Non-Transmittable Codewords (NTCs) into Viterbi Algorithm Decoder has emerged as one of the best
ways of improving performance of the Viterbi Algorithm Decoder. However, the performance has been tested only in hard
decision Viterbi Decoder in telecommunication systems, but not in soft deci- sion Viterbi Decoder and storage media. Most
storage media use Reed Solomon (RS) Algorithm Decoder. Yet, the field experience still shows failure of the algorithm in
correcting burst errors in reading data from the storage media; leading into data loss. This paper introduces the Soft Viterbi
Algorithm Decoding enhanced with Non- Transmittable Codewords for storage media. Matlab software was used to simulate
the algorithm and the performance was measured by comparing residual errors in a data length of one million bits. Additive
White Gaussian Noise model was applied to distort the stored data. The performance comparison was made against the Reed
Solomon code, Normal Soft Viterbi and Hard decision Viterbi enhanced with NTCs. The results showed that the Soft Viterbi
Algorithm enhanced with NTCs performed remarkably better by 88.98% against RS, 84.31% against Normal Soft Viterbi and
67.26% against Hard Viterbi enhanced with NTCs.