给定一个信号

a)画出低通信号的波形；

b)画出抽样速率为 fs为 4HZ 的抽样序列

c)从抽样序列中恢复出原始信号

当抽样速率为 fs  1.5HZ ，画出恢复后的波形。

当抽样速率为 fs  1.5HZ ，画出恢复后的波形。-Given a signal

a) Draw a low pass signal waveform

b) Draw the sampling rate fs is sampling sequence 4HZ

c) From the sample sequence to recover the original signal

When the sampling rate is fs 　1.5HZ, waveform draw restored.

When the sampling rate is fs 　1.5HZ, waveform draw restored.