Achieving AWGN Channel Capacity with Sparse Graph Modulation and "In the Air" Coupling

TL;DR

This paper demonstrates that using sparse graph modulation with spatial coupling in a multiple access channel enables achieving the AWGN channel capacity through iterative interference cancellation decoding.

Contribution

It introduces a novel approach combining sparse graph modulation and spatial coupling to reach channel capacity with equal power transmissions.

Findings

Spatial graph coupling enables capacity achievement.

Iterative interference cancellation effectively decodes coupled signals.

The method approaches the theoretical AWGN channel capacity.

Abstract

Communication over a multiple access channel is considered. Each user modulates his signal as a superposition of redundant data streams where interconnection of data bits can be represented by means of a sparse graph. The receiver observes a signal resulting from the coupling of the sparse modulation graphs. Iterative interference cancellation decoding is analyzed. It is proved that spatial graph coupling allows to achieve the AWGN channel capacity with equal power transmissions.