Discrimination difficulty of M-ary Phase Position Shift Keying(MPPSK) receiver is usually caused by unstable envelope caused by channel fading,impulse interference,and signal fluctuation.Filtering mechanism using impacting filter can transform phase transition to amplitude impact.The analog to digital converter(ADC) in receiver is replaced by high-speed comparator to give deep amplitude limiting to the received signals.This method enhances anti-jamming capabilities and simplifies hardware implementation,ensuring that the response envelope of the impacting filter is basically stable and fluctuation seldom happens even in fading channel.This makes it possible to simplify demodulations with a fixed discrimination threshold,which improves the performance of the MPPSK reception.%针对多元位置相移键控（MPPSK）系统因信道衰落、脉冲干扰和信号起伏等原因引起包络起伏而导致的判决困难,利用数字冲击滤波器可将信号的相位跳变转化为幅度冲击的特殊滤波机理,对接收信号采用高速比较器取代ADC进行深度限幅。一方面增强了接收机的抗干扰能力,简化了硬件实现;另一方面即使对于衰落信道,也基本能保证冲击滤波器输出的信号包络的稳定,从而可以采用固定的判决门限简化解调计算,并提高MPPSK接收性能。
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