Transmit Beamforming for Communication and Self-Interference Cancellation in Full Duplex MIMO Systems: A Trade-Off Analysis

• Published in: IEEE transactions on wireless communications Vol. 20; no. 6; pp. 3760 - 3769
• Main Authors: Huang, Xiaojing, Tuyen Le, Anh, Guo, Y. Jay
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.06.2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adaptive filters; Array signal processing; Beamforming; Channels; Codes; Eigenvalues; Error reduction; full duplex radio; Interference; Interference cancellation; Mathematical analysis; MIMO (control systems); MIMO communication; multiple input multiple output; Precoding; Receiving antennas; self-interference cancellation; Tradeoffs; Transceivers; Transmit beamforming; Transmitting antennas
• ISSN: 1536-1276; 1558-2248
• DOI: 10.1109/TWC.2021.3053542

The performance of transmit beamforming for both optimized precoding and self-interference cancellation (SIC) in full duplex multiple input multiple output (MIMO) transceivers is analysed in this paper. With sub-space dimension larger than that of the null-space of the self-interference channels, the precoding error is reduced but the interference suppression ratio (ISR) is degraded, resulting in a trade-off between multibeam communication and MIMO SIC. An analytical approach for the ISR evaluation is proposed assuming known eigenvalue distribution of the self-interference channels, and a closed-form ISR expression is derived after applying a uniform distribution approximation. The ISR and precoding error trade-off curves are also formulated. Joint SIC by transmit beamforming and beam-based analog adaptive filters over both propagation and analog domains is proposed to achieve better SIC performance and enable more flexible receive antenna selection. Simulation results verify the theoretical analyses.