Digital Self-Interference Cancellation Based on Independent Component Analysis for Co-Time Co-frequency Full-Duplex Communication Systems

Co-frequency and co-time full-duplex (CCFD) technique claims to be the most potential duplex scheme for the next generation system, since it can double the spectral efficiency. The challenge of CCFD wireless communication systems lies in mitigating the self-interference (SI). In this paper, we focus on the digital SI cancellation (SIC) in the CCFD systems. The performance of the traditional digital cancellation techniques is mainly limited by the nonlinearity of the components of local transmitter. Aiming at the issue an auxiliary receive chain is employed in this paper. In addition, by exploiting the independence between signal of interest and self-interfering signal, two digital SIC algorithms based on independent component analysis are developed for two application scenarios of the CCFD technique, i.e., CCFD satellite communication systems and ground CCFD communication systems. Instead of achieving cancellation by reconstructing self-interfering signal in other works, the proposed algorithms extract desired signal from the received signal. Simulation results indicate that the proposed algorithms outperform conventional least square digital cancellation method.