Self-Interference Cancellation with Nonlinear Distortion Suppression for Full-Duplex Systems

TL;DR

This paper proposes a nonlinear distortion suppression scheme for full-duplex OFDM systems that enhances self-interference cancellation, bringing performance close to ideal linear systems by jointly estimating channel and nonlinearity coefficients.

Contribution

It introduces an iterative joint estimation method to suppress nonlinear distortion, significantly improving self-interference cancellation in full-duplex OFDM systems.

Findings

Achieves less than 0.5dB performance gap from linear systems

Enhances cancellable self-interference power through distortion suppression

Demonstrates effectiveness via numerical simulations

Abstract

In full-duplex systems, due to the strong self-interference signal, system nonlinearities become a significant limiting factor that bounds the possible cancellable self-interference power. In this paper, a self-interference cancellation scheme for full-duplex orthogonal frequency division multiplexing systems is proposed. The proposed scheme increases the amount of cancellable self-interference power by suppressing the distortion caused by the transmitter and receiver nonlinearities. An iterative technique is used to jointly estimate the self-interference channel and the nonlinearity coefficients required to suppress the distortion signal. The performance is numerically investigated showing that the proposed scheme achieves a performance that is less than 0.5dB off the performance of a linear full-duplex system.