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

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.

Automated summary

Massive MIMO and full-duplex are potential technologies for achieving the required spectral efficiency in 5G communications. One key challenge in implementing practical full-duplex massive MIMO systems is effectively mitigating self-interference (SI). Existing literature has not sufficiently compared the performance of different SI cancellation methods based on actual channel characteristics. This paper presents a performance analysis of SI cancellation methods in full-duplex massive MIMO systems, considering imperfect channel estimation. Analytical and numerical results show that spatial suppression outperforms SI subtraction in terms of ergodic rates, due to the correlation between the precoder and SI channel estimation error. The paper also discusses the performance of different methods under various system constraints.