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；

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）

改用HDB3码，画出前20个符号对应的波形

改用密勒码，画出前20个符号对应的波形

分别对上述1000个符号的波形进行功率谱估计，画出功率谱

改变信源“0”的概率，观察AMI码的功率谱变化情况-A length of 1000 random binary sequence, and " 0"　with a probability of 0.8, " 1"　with a probability of 0.2　the AMI code above zero, the pulse width of the symbol width of 50 , the waveform sampling rate Symbol rate 8 times, draw the top 20 of the waveform corresponding to the symbol (the first 20 and gives the source sequence) switch HDB3 code, the first 20 to draw a waveform corresponding to the symbol to switch Miller code, the first 20 symbols correspond to draw The waveforms of the symbol of the waveform 1000 power spectrum estimation, shown to change the source power spectrum " 0" , the probability of observation of the power spectrum of AMI code changes