说明：  A. 产生一个长为1000的二进制随机序列，“0”的概率为0.8，”1”的概率为0.2；B. 对上述数据进行归零AMI编码，脉冲宽度为符号宽度的50%，波形采样率为符号率的8倍，画出前20个符号对应的波形（同时给出前20位信源序列）；C. 改用HDB3码，画出前20个符号对应的波形；D. 改用密勒码，画出前20个符号对应的波形；E. 分别对上述1000个符号的波形进行功率谱估计，画出功率谱；F. 改变信源“0”的概率，观察AMI码的功率谱变化情况；
(have a length of 1,000 random binary sequence, "0" with a probability of 0.8, "a" with a probability of 0.2; B. above zero AMI data coding, and pulse width of symbols width of 50%, waveform sampling rate Symbol rate for the eight times that he painted before the 20 symbols corresponding waveforms (also given before 20 Source sequence); C. HDB3 code switch to depict the former 20 symbols corresponding waveform; D. Miller to switch codes to depict the former 20 symbols corresponding waveform; E. respectively above 1,000 symbols for the power spectrum waveform estimated to depict the power spectrum; F. Change source "0" the probability to observe AMI code changes in the power spectrum;)