参考信号耦合有用信号对干扰对消系统的影响及其抑制

分析了参考信号耦合有用信号时，实际自适应干扰对消系统的时域特性。分析表明，参考信号含有用信号导致系统时变，改变系统的最佳权值，使系统的干扰对消效果下降，并对有用信号的接收产生影响。根据实际共平台通信系统的收发耦合特性，从时域角度分析得到系统干扰对消比和有用对消比的计算表达式，并得到干扰对消比和有用对消比随相对时延相位变化的规律。提出一种时延匹配方法，通过匹配参考信号提取点至正交功分器输出与接收天线至合成信号注入点间的时延，可以有效抑制参考信号耦合有用信号导致干扰对消效果下降的问题。仿真结果表明，所提出的时延匹配方法能消除有用信号对干扰对消比的影响，还能提高干扰对消效果。

Influence and its suppression of desired signal coupling to reference signal to interference cancellation system

The time-domain characteristics of adaptive interference cancellation system with desired signal coupling to reference signal were analyzed. The analyses reveal the desired signal makes the system a time-variation system and the optimal weights were changed, which made the performance of cancellation system decreased and infulence the reception of the desired signal. According to the coupling characteristics of common platform communication system, the formulas of (ICR) interference cancellation ratio and (DCR) desired cancellation ratio were gained in time-domain. The law of ICR and DCR varying with relative delay phase was got. The method of delay time matching was brought forward. Through matching the delay time of the extraction point of the reference signal to the output of the orthogonal divider and the receiving antenna to the injection point of the synthetic signal could suppress the decrease of ICR for the reference signal coupling desired signal. The simulation results reveal that the delay time matching can not only prevent the decrease of ICR for desired signal in ref-erence signal but also improve the performance of cancellation system.