针对同时同频全双工场景中,宽带射频自干扰抵消方案缺乏性能分析这一问题,以多抽头射频域自干扰抵消结构为基础,以最小化剩余自干扰信号功率为准则,讨论了该结构中各抽头参数的最优解,进而分析了可实现的最佳自干扰抑制效果。数值与仿真结果表明,多抽头射频域自干扰抵消结构最佳的自干扰抑制性能与自干扰信号带宽、载波频率以及抽头时延与自干扰信道多径时延之差有关。信号带宽越大,或抽头时延与自干扰信道多径时延之差越大,干扰抑制性能越差;干扰抑制效果随载波频率的增加近似呈周期性振荡。
Due to the lack of performance analysis of the RF domain broadband self-interference cancellation algorithms in the co-time and co-frequency full duplex system, the multi-tap RF domain self-interference cancellation structure were considered, and the optimal solutions of its parameters to minimize the residual interference signal power were discussed, then its achievable interference cancellation capability was analyzed. By analysis and simulation, the performance of the multi-tap structure was associated with the interference bandwidth, the carrier frequency, and the differences between the multi-tap delays and multipath delays of the self-interference channel. The greater the signal bandwidth is, or the larger the differences between the multi-tap delays and multipath delays are, the worse the interference cancellation performance is. Besides, the interference cancellation performance is periodic oscillation with the increase of carrier frequency.