Performance Analysis of Self-Interference Cancellation in Full-Duplex Massive MIMO Systems: Subtraction versus Spatial Suppression

TL;DR

This paper compares subtraction and spatial suppression methods for self-interference cancellation in full-duplex massive MIMO systems, showing spatial suppression outperforms subtraction under imperfect channel estimation in certain scenarios.

Contribution

It provides a comprehensive performance analysis of SI cancellation methods considering actual channel characteristics and system constraints in FD massive MIMO systems.

Findings

Spatial suppression outperforms subtraction in ergodic rates with imperfect channel estimation.

Performance depends on system constraints like power, sum rates, and channel estimation accuracy.

Analytical and numerical results validate the superiority of spatial suppression in specific conditions.

Abstract

Massive multiple-input multiple-output (MIMO) and full-duplex (FD) are promising candidates for achieving the spectral efficiency to meet the needs of 5G communications. One essential key to realizing practical FD massive MIMO systems is how to effectively mitigate the self-interference (SI). Conventionally, however, the performance comparison of different SI methods by reflecting the actual channel characteristics was insufficient in the literature. Accordingly, this paper presents a performance analysis of SI cancellation (SIC) methods in FD massive MIMO systems. Analytical and numerical results confirm that, in an imperfect channel-estimation case, the ergodic rates performance of the spatial suppression in the uplink outperforms those of the SI subtraction, due to the correlation between the precoder and the estimation error of the SI channel. In addition, we discuss which method performs better under different given system constraints such as uplink and downlink sum rates, the total transmit power, and the power scaling law.