Simple Gray Coding and LLR Calculation for MDS Modulation Systems

TL;DR

This paper introduces MDS modulation, a simple coding technique that simplifies Gray coding and LLR calculations in index modulation systems, and demonstrates its superior error performance over traditional IM methods.

Contribution

It proposes a novel MDS-based modulation scheme that simplifies practical implementation issues and improves error performance compared to existing index modulation techniques.

Findings

MDS modulation simplifies Gray coding and LLR calculations.

MDS modulation outperforms IM in coded error performance.

The method enhances practical applicability of modulation schemes.

Abstract

Due to dependence between codeword elements, index modulation (IM) and related modulation techniques struggle to provide simple solutions for practical problems such as Gray coding between information bits and constellation points; and low-complexity log-likelihood ratio (LLR) calculations for channel-encoded information bits. In this paper, we show that a modulation technique based on a simple maximum distance separable (MDS) code, in other words, MDS modulation, can provide simple yet effective solutions to these problems, rendering the MDS techniques more beneficial in the presence of coding. We also compare the coded error performance of the MDS methods with that of the IM methods and demonstrate that MDS modulation outperforms IM.