Analysis of bi-directional multi-antenna relaying with imperfect self-interference cancellation

This article considers the two-way bidirectional relaying scenario, in which it is crucial to improve the transmission efficiency to make up for the extra hop in the communication. Single-antenna two-way relaying can be implemented through a Self-Interference (SI) cancellation scheme known as Bidirectional Amplification of Throughput (BAT). This paper analyzes the impact that an imperfect cancellation has on the system performance. Additionally, some insights are provided on the achievable gains when multi-antenna relay stations are employed. An extension of the BAT concept to this multi-antenna case is formulated and compared to a Zero-Forcing (ZF) approach.