A Message Passing Detection based Affine Frequency Division Multiplexing Communication System

TL;DR

This paper introduces a low-complexity message passing detection algorithm for Affine Frequency Division Multiplexing (AFDM), enhancing performance in high-speed wireless channels by leveraging channel sparsity and addressing limitations of OTFS.

Contribution

It proposes a novel message passing detection method for AFDM, improving detection efficiency and performance over traditional techniques in high-mobility scenarios.

Findings

MP detection outperforms MMSE and MRC methods

AFDM achieves comparable performance to OTFS

Efficient joint interference cancellation and detection

Abstract

The next generation of wireless communication technology is anticipated to address the communication reliability challenges encountered in high-speed mobile communication scenarios. An Orthogonal Time Frequency Space (OTFS) system has been introduced as a solution that effectively mitigates these issues. However, OTFS is associated with relatively high pilot overhead and multiuser multiplexing overhead. In response to these concerns within the OTFS framework, a novel modulation technology known as Affine Frequency Division Multiplexing (AFDM) which is based on the discrete affine Fourier transform has emerged. AFDM effectively resolves the challenges by achieving full diversity through parameter adjustments aligned with the channel's delay-Doppler profile. Consequently, AFDM is capable of achieving performance levels comparable to OTFS. As the research on AFDM detection is currently limited, we present a low-complexity yet efficient message passing (MP) algorithm. This algorithm handles joint interference cancellation and detection while capitalizing on the inherent sparsity of the channel. Based on simulation results, the MP detection algorithm outperforms Minimum Mean Square Error (MMSE) and Maximal Ratio Combining (MRC) detection techniques.