信号与系统实验答案

clear clc T1 = 0.5; T2 = 0.2; T3 = 0.01; Fs1 = 1 / T1; Fs2 = 1 / T2; Fs3 = 1 / T3; Nc1 = 100 / T1; Nc2 = 100 / T2; Nc3 = 100 / T3; %T1 for n = -Nc1 : 1 : Nc1 nT1(n + Nc1 + 1) = T1 * n; f1(n + Nc1 + 1) = (sin(10 * pi * nT1(n + Nc1 + 1)) + eps) ./ (10 * pi * nT1(n + Nc1 + 1) + eps); end step = 0.05; t = -5 : step : 5; for N = 1 : length(t) for n = 1 : length(nT1) ff1(n) = f1(n) * (sin(pi * Fs1 * (t(N) - nT1(n))) + eps) ./ (pi * Fs1 * (t(N) - nT1(n)) + eps); end fa1(N) = sum(ff1); end subplot(3, 1, 1); G1 = fft(fa1); plot(abs(G1), N); %T2 for n = -Nc2 : 1 : Nc2 nT2(n + Nc2 + 1) = T2 * n; f2(n + Nc2 + 1) = (sin(10 * pi * nT2(n + Nc2 + 1)) + eps) ./ (10 * pi * nT2(n + Nc2 + 1) + eps); end step = 0.05; t = -5 : step : 5; for N = 1 : length(t) for n = 1 : length(nT2) ff2(n) = f2(n) * (sin(pi * Fs2 * (t(N) - nT2(n))) + eps) ./ (pi * Fs2 * (t(N) - nT2(n)) + eps); end fa2(N) = sum(ff2); end subplot(3, 1, 2); G2 = fft(fa2); plot(abs(G2), N); %T3 for n = -Nc3 : 1 : Nc3 nT3(n + Nc3 + 1) = T3 * n; f3(n + Nc3 + 1) = (sin(10 * pi * nT3(n + Nc3 + 1)) + eps) ./ (10 * pi * nT3(n + Nc3 + 1) + eps); end step = 0.05; t = -5 : step : 5; for N = 1 : length(t) for n = 1 : length(nT3) ff3(n) = f3(n) * (sin(pi * Fs3 * (t(N) - nT3(n))) + eps) ./ (pi * Fs3 * (t(N) - nT3(n)) + eps); end fa3(N) = sum(ff3); end subplot(3, 1, 3); G3 = fft(fa3); plot(abs(G3), N);