产生一512点的随即序列xe(n)并用xc(n)和 xe(n)做线形卷积，观察卷积前后xe(n) 频谱的变化。要求将xe(n)分成8段，采用重叠保留法。-512 point sequence Xe (n) and XC (n) and Xe (n) to do linear convolution, the Xe (n) spectrum changes before and after convolution is observed. Xe (n) is divided into 8 segm