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-Have a length of 1000 random binary sequence, the probability of "0" is 0.8, and the probability of "1" is 0.2

Said data zeroing AMI coding, pulse width of 50　of the width of the symbol, the symbol rate of the waveform sampling rate of 8 times, to draw the first 20 symbols of the corresponding waveform (also given 20 source sequence)

HDB3 code switch, draw 20 symbols corresponding waveform

Switch to Miller code, draw 20 symbols corresponding waveform

The 1000 symbol waveform power spectrum estimation, draw power spectrum

The probability of "0" to change the source observed power spectrum of the AMI code changes