基于辅助符号的非线性自干扰抵消算法及其简化实现

同频同时全双工是第5代(5G)通信关键技术之一，数字自干扰抵消算法是其重要研究方向。针对非线性数字自干扰抵消算法中，失真系数估计受到自干扰信道估计误差的影响这一问题，该文提出一种基于辅助符号的非线性自干扰抵消算法，通过对辅助符号做自干扰抵消，将信道估计符号的失真误差映射到其抵消结果中并提取出来，从中估计失真系数。接着针对算法开销问题提出一种简化实现方案。仿真结果显示，接收自干扰信号为-5 dBm时，算法可将自干扰非线性失真分量抵消至约-100 dBm，且性能随接收自干扰功率降低而提高。

Auxiliary Symbol-based Nonlinear Self-interference Cancellation Algorithm and Simplified Implementation

In-band full duplex is a key concept brought up in 5G, and digital Self-Interference (SI) cancellation has become an important field attracting much attention. SI channel estimation error introduced by nonlinear distortion leads to deleterious effect on the accurate estimation of distortion coefficient. This paper proposes a nonlinear SI cancellation algorithm based on an auxiliary symbol. The channel estimation error is mapped into cancellation residuals by performing SI cancellation for the designed auxiliary symbol, and then extracted to be an independent attributor for distortion coefficient estimation. A simplified implementation is proposed further for reducing the overhead of the algorithm. Simulation results show that the nonlinear SI component is suppressed to about -100 dBm with -5 dBm SI power received. In addition, the lower the received SI power is, the better the performance tends to be.