Message Passing-Vector Symbol Decoding for LDPC Codes with Nonbinary Symbols

Abstract

This paper proposes a new decoding technique called “MP-VSD” for LDPC codes with large nonbinary symbols. It combines Hard Decision Message Passing (HDMP) with Vector Symbol Decoding (VSD). VSD usually uses very short block codes to limit the number of error symbols, which limits the size of matrix inversion required in the VSD decoding step. MP-VSD can correct more than 60% of the correctable error patterns of VSD for an (60, 30) LDPC code with no matrix inversions in a 2-state fading channel model. Thus, longer block codes may be used for nonbinary symbols.