非合作信号射频域干扰抵消性能分析

针对航空测控系统面临宽带干扰时,缺乏有效的抗干扰手段的问题,研制了定向天线和全向天线的接收结构,可在射频域抵消外来的非合作信号,以保证合作信号的准确接收。并讨论了单抽头和多抽头两种结构模型。利用干扰抵消算法,以剩余非合作信号功率最小为准则,进行了理论推导。并提出在多抽头结构的工程实现中采用矢量调制器来进行幅度和相位的调整。仿真结果表明:对于单抽头结构,在2.6GHz频段,对于带宽100 MHz的信号,当延迟线长度调整误差为2%时,最优的干扰抑制能力达到了45dB,当考虑幅度调整误差为10%时,干扰抑制能力会降低约10dB;对于多抽头结构,使用与单抽头相同的信号。以双抽头为例,当传输时延差固定时,最优干扰抑制能力可达81dB,仿真结果从理论上验证了接收结构的可行性。

Performance analysis of non-cooperation signal interference cancellation at RF domain

Due to the lack of effective methods for broadband interference suppression in aerospace TT&C system, the receiving structure of the directional antenna and the omni-directional antenna is provided. Non-cooperative signal is cancelled at RF domain, so as to ensure the accurate reception of the cooperative signal. Two syntactic models of the single tap and the multi-tap are discussed separately. Theoretical derivation is proceeded with minimizing the residual non-cooperative signal power as criterion by using the interference cancellation algorithm. It is suggested that the vector modulator be used to adjust the amplitude and phase in the multi-tap structure. The simulation result shows that, for the single tap structure, when the delay line error is 2%, the best interference cancellation capability reaches 45 dB in the 2.6 GHz band, for the bandwidth 100 MHz siganl; while when amplitude error is 10%, the interference cancellation capability decreases by 10 dB; for the multi-tap structure, the same signal is used as the single tap structure. In the double tap structure, the best interference cancellation capability reaches 81 dB when the transmission delay is confirmed. The simulation results verify the feasibility of the receiver structure.