可用于DSSS系统时变干扰抑制的IIR滤波器设计

The Design of IIR Filters for Time-Varying Interference Suppression in DSSS Communications Systems

在理想的干扰瞬时频率估计条件下,推导Kwan-Martin结构IIR干扰抑制滤波器相关输出信干噪比改善因子的闭合表达式。与五系数时变FIR滤波器干扰抑制性能比较表明,IIR滤波器对DSSS信号的失真远小于FIR滤波器,信干噪比改善因子与干扰瞬时频率及系统扩展比无关,干扰抑制性能优于时变FIR滤波结构。

On condition that the accurate estimation of instantaneous frequency of the interference, closed-form exprcssion of the improvement of Signal to Interference and Noise Ratios （SINR） of Kwan-Martin IIR filter is derived. It is proved comparing with the five-coefficient FIR that the IIR filter introduced less distortion to DSSS signal, and that the improvement of SINR of IIR filter is independent with the instantaneous frequency of interference and spreading gain. A better interference suppression performance can be achieved with IIR filter.