Novel Cancellation Techniques and Throughput Analysis for 6G Full-Duplex Wireless System

Recent researches show that it is possible to achieve full-duplex system if the self-interference signal could be cancelled completely for 6G research. The majority of the overall self-interference cancellation is contributed by passive cancellation. The lowest complexity cancellation technique is digital cancellation. Therefore, this paper presents a novel passive cancellation technique based on multi-path effect and a novel digital cancellation method considering nonlinearity factor in full-duplex system. Therein, for passive cancellation method, theoretical analysis is presented and practical experiments show that it can achieve about 50 dB only in 10-cm space. For digital cancellation method, a model based on practical platform is given and it can achieve about 30 dB under high transmit power. In addition, two relay schemes based on full-duplex for two-way relay channel called FD-DF (full-duplex decode-and-forward) and FD-AF (full-duplex amplify-and-forward) are presented. Two proposed schemes can nearly double the system throughputs especially in high signal-to-noise radio regions compared with traditional AF scheme.