On the Performance of Low Density Parity Check Codes for Gaussian Interference Channels

TL;DR

This paper investigates the use of LDPC codes in Gaussian interference channels, demonstrating improved achievable rates over traditional methods through various modulation schemes and coding strategies.

Contribution

It introduces explicit LDPC coding schemes for Gaussian interference channels and shows their effectiveness in achieving higher rates than time sharing in different interference scenarios.

Findings

LDPC codes outperform single-user codes with time sharing in strong interference scenarios.

QPSK modulation with LDPC codes achieves higher rates than traditional methods.

Han-Kobayashi scheme with LDPC codes improves achievable rates under general interference.

Abstract

In this paper, two-user Gaussian interference channel(GIC) is revisited with the objective of developing implementable (explicit) channel codes. Specifically, low density parity check (LDPC) codes are adopted for use over these channels, and their benefits are studied. Different scenarios on the level of interference are considered. In particular, for strong interference channel examples with binary phase shift keying (BPSK), it is demonstrated that rates better than those offered by single user codes with time sharing are achievable. Promising results are also observed with quadrature-shift-keying (QPSK). Under general interference a Han-Kobayashi coding based scheme is employed splitting the information into public and private parts, and utilizing appropriate iterative decoders at the receivers. Using QPSK modulation at the two transmitters, it is shown that rate points higher than those achievable by time sharing are obtained.