傅里叶变换和傅里叶变换的性质,周期信号和非周期信号的频谱分析,卷积和卷积定理,抽样信号的傅里叶变换和抽样定理,相关、能量谱和功率谱.-Fourier transform and Fourier transform nature, the cycle-cycle signal and the signal spectrum analysis, Convolution and convolution theorem, the sampling signal to the Fourier transf

分析双极性不归零码的功率谱特性请输入随机序列的长度N= -ubplot(312) plot(f,lpf) title( 低通滤波器 ) axis([-fs/2 fs/2-0.2 1.2]) subplot(313) plot(f,abs(yr_lpf)/N) title( 经低通滤波后的频谱 ) xlabel( f /Hz )