中文说明：信道失真示意图，直观展示线性无失真信道，幅频失真信道、相频失真、群时延失真信道，以及与无失真信道的对比
English Description：
Channel distortion schematic, intuitive display linear distortion channel , frequency and amplitude distortion channel, phase-frequency distortion, Group delay distortion channel, as well as comparison with distortion free channel