Sliding-Window Superposition Coding:Two-User Interference Channels

TL;DR

This paper introduces a low-complexity sliding-window superposition coding scheme for two-user interference channels that achieves optimal rate regions and can be practically implemented with standard codes.

Contribution

It proposes a novel coding scheme that outperforms rate-splitting multiple access by achieving the Han--Kobayashi inner bound with practical implementation.

Findings

Achieves the Han--Kobayashi inner bound for interference channels.

Implemented successfully using commercial channel codes.

Provides a practical, low-complexity solution for interference channel communication.

Abstract

A low-complexity coding scheme is developed to achieve the rate region of maximum likelihood decoding for interference channels. As in the classical rate-splitting multiple access scheme by Grant, Rimoldi, Urbanke, and Whiting, the proposed coding scheme uses superposition of multiple codewords with successive cancellation decoding, which can be implemented using standard point-to-point encoders and decoders. Unlike rate-splitting multiple access, which is not rate-optimal for multiple receivers, the proposed coding scheme transmits codewords over multiple blocks in a staggered manner and recovers them successively over sliding decoding windows, achieving the single-stream optimal rate region as well as the more general Han--Kobayashi inner bound for the two-user interference channel. The feasibility of this scheme in practice is verified by implementing it using commercial channel codes over the two-user Gaussian interference channel.