% 第三章: 例3.20
%             用sinc函數(shù)的重構(gòu)信號(hào)和混疊
%
% 離散時(shí)間信號(hào) x2(n)
Ts = 0.001; Fs = 1/Ts; n = -5:1:5; nTs = n*Ts;
x = exp(-1000*abs(nTs));
% 模擬信號(hào)重構(gòu)
Dt = 0.00005;
t = -0.005:Dt:0.005;
xa = x * sinc(Fs*(ones(length(nTs),1)*t-nTs'*ones(1,length(t))));
% 校驗(yàn)
error = max(abs(xa - exp(-1000*abs(t))))
% 繪圖
subplot(1,1,1)
subplot(2,1,2);plot(t*1000,xa);
xlabel('t 毫秒'); ylabel('xa(t)')
title('用sinc函數(shù)由x1(n)重構(gòu)信號(hào)和混疊'); hold on
stem(n*Ts*1000,x); hold off