Self-Interference in Full-Duplex Multi-User MIMO Channels

TL;DR

This paper analyzes residual self-interference in full-duplex multi-user MIMO channels, deriving exact moments and providing a Gamma approximation for the interference distribution under various system configurations.

Contribution

It introduces a novel analytical framework for characterizing residual self-interference in full-duplex MIMO systems using moments and Gamma approximation.

Findings

Closed-form expressions for first and second moments of residual SI.

Gamma distribution approximation for residual SI.

Applicable to arbitrary precoding, decoding, and system parameters.

Abstract

We consider a multi-user multiple-input multiple-output (MIMO) setup where full-duplex (FD) multi-antenna nodes apply linear beamformers to simultaneously transmit and receive multiple streams over Rician fading channels. The exact first and second positive moments of the residual self-interference (SI), involving the squared norm of a sum of non-identically distributed random variables, are derived in closed-form. The method of moments is hence invoked to provide a Gamma approximation for the residual SI distribution. The proposed theorem holds under arbitrary linear precoder/decoder design, number of antennas and streams, and SI cancellation capability.