Disjoint LDPC Coding for Gaussian Broadcast Channels

TL;DR

This paper introduces a novel LDPC coding method for Gaussian broadcast channels that simplifies decoding by avoiding joint decoding and code optimization, reducing complexity while maintaining near-capacity performance.

Contribution

A new labeling strategy for LDPC codes that enables near-capacity performance without joint decoding or code optimization in broadcast channels.

Findings

Successfully designed LDPC code pairs for various capacity boundary points.

Achieved near-capacity performance with reduced decoding complexity.

Demonstrated effectiveness across different rate pairs.

Abstract

Low-density parity-check (LDPC) codes have been used for communication over a two-user Gaussian broadcast channel. It has been shown in the literature that the optimal decoding of such system requires joint decoding of both user messages at each user. Also, a joint code design procedure should be performed. We propose a method which uses a novel labeling strategy and is based on the idea behind the bit-interleaved coded modulation. This method does not require joint decoding and/or joint code optimization. Thus, it reduces the overall complexity of near-capacity coding in broadcast channels. For different rate pairs on the boundary of the capacity region, pairs of LDPC codes are designed to demonstrate the success of this technique.