Low-Density Parity-Check Codes for Nonergodic Block-Fading Channels

TL;DR

This paper develops a new family of LDPC codes optimized for nonergodic block-fading channels, achieving near-outage-limit performance under iterative decoding, and addresses the limitations of maximum-likelihood optimized codes.

Contribution

Introduction of a novel family of full-diversity LDPC codes that perform well under iterative decoding for all block-lengths in nonergodic channels.

Findings

Codes exhibit near-outage-limit performance.

New codes outperform traditional LDPC designs.

Performance rivals multiplexed turbo codes.

Abstract

We solve the problem of designing powerful low-density parity-check (LDPC) codes with iterative decoding for the block-fading channel. We first study the case of maximum-likelihood decoding, and show that the design criterion is rather straightforward. Unfortunately, optimal constructions for maximum-likelihood decoding do not perform well under iterative decoding. To overcome this limitation, we then introduce a new family of full-diversity LDPC codes that exhibit near-outage-limit performance under iterative decoding for all block-lengths. This family competes with multiplexed parallel turbo codes suitable for nonergodic channels and recently reported in the literature.