信号与系统matlab实验傅里叶分析及应用报告答案

'),ylabel('f(t)'); Рtitle('由f(nTs)信号重建得到Sa(t)信号'); Р周期取2*pi/3 s:Р实验代码如下:Рwm=2; Рwc=1.2*wm; РTs=2*pi/3;Рdt=0.1;Рt1=-4:dt:4;Рft=sinc(t1/pi).*( heaviside (t1+10)- heaviside (t1-10));РN=500;Рk=-N:N;РW=2*pi*k/((2*N+1)*dt);Рn=-100:100;РnTs=n*Ts;Рfst=sinc(nTs/pi).*( heaviside (nTs+10)- heaviside (nTs-10));Рsubplot(221);Рplot(t1,ft,':'),hold onРstem(nTs,fst),grid onРaxis([-4 4 -1 1]);Рxlabel('Time (sec)'),ylabel('fs(t)')Рtitle('Sa(t)抽样后的信号'),hold off;РFsw=Ts*fst*exp(-j*nTs'*W);Рsubplot(222)Рplot(W,abs(Fsw),'c'),grid onРaxis([-10 10 -3 10])Рxlabel('\omega'),ylabel('Fsw')Рtitle('Sa(t)抽样信号的频谱')Рt=-10:dt:10;Рf=fst*Ts*wc/pi*sinc((wc/pi)*(ones(length(nTs),1)*t-nTs'*ones(1,length(t))));Рsubplot(223);Рplot(t,f,'m:'),grid on; Рaxis([-10 10 -2 9]);Рxlabel('t'),ylabel('f(t)'); Рtitle('由f(nTs)信号重建得到Sa(t)信号');