Split-Extended LDPC codes for coded cooperation

TL;DR

This paper introduces Split-Extended LDPC codes, a novel relay-based code design that enhances error correction in relay channels by splitting and extending code bits, approaching channel capacity.

Contribution

The paper presents a new split-and-extend LDPC code design for relay channels, improving correction capacity and compatibility with existing codes.

Findings

Enhanced error correction performance in relay channels.

Approaches channel capacity closely as shown by density evolution.

Compatible with existing LDPC codes for practical deployment.

Abstract

We propose a new code design that aims to distribute an LDPC code over a relay channel. It is based on a split-and-extend approach, which allows the relay to split the set of bits connected to some parity-check of the LDPC code into two or several subsets. Subsequently, the sums of bits within each subset are used in a repeat-accumulate manner in order to generate extra bits sent from the relay toward the destination. We show that the proposed design yields LDPC codes with enhanced correction capacity and can be advantageously applied to existing codes, which allows for addressing cooperation issues for evolving standards. Finally, we derive density evolution equations for the proposed design, and we show that Split-Extended LDPC codes can approach very closely the capacity of the Gaussian relay channel.