多抽头结构的宽带射频干扰对消及优化设计

Optimization design of wideband RF interference cancellation based on multi-tap structure

多抽头对消结构可用于抑制大功率发射机产生的宽带噪声干扰,抽头数目和抽头延时间隔的选取直接影响干扰抑制效果,但是现有文献缺少其选取策略及对多抽头干扰对消系统性能的影响分析。针对此问题,建立了多抽头数模混合对消系统的理论模型,求解了抽头权值的最优值,首次得到了抽头数目和抽头延时间隔与对消比、收敛速度之间的解析关系。针对权值估计复杂的问题,提出了指数形式的迭代加权方法,有效提高了权值的估计精度和干扰对消比。针对抽头数目和抽头延时间隔的选取策略,提出了对消比最高、收敛速度最快的选取准则,大大降低了费效比,可用于指导多抽头对消结构中抽头数目和延时间隔的选择。结果表明,对于带宽为30 MHz的信号,系统优化后的对消比不低于33 dB,有效解决了宽带干扰问题。

The multi-tap interference cancellation structure can be used to suppress the wideband noise interference generated by high-power transmitters.The selection of the number of taps and the tap delay interval directly affects the interference suppression effect.However,the existing references lack selection methods and the analysis of the impact of multi-tap interference cancellation system performance.To solve this problem,the theoretical model of the multi-tap digital-analog hybrid cancellation system is established,the optimal value of the tap weight is solved,and the analytical relationship between the tap number and delay interval and the interference cancellation ratio(ICR)and convergence speed is obtained for the first time.To reduce the complexity of weight estimation,the exponential iterative weighting method is proposed,which effectively improves the weight estimation accuracy and the ICR.For the selection strategy of the number of taps and the tap delay interval,the selection criterion with the highest ICR and the fastest convergence speed is proposed,which greatly reduces the cost-effectiveness ratio and can provide reference for the selection of the number of taps and tap delay interval in the multi-tap cancellation structure.The results show that for the signal with a bandwidth of 30 MHz,the ICR of the optimized system is not less than 33 dB,which effectively solves the problem of wideband interference.