ex031700.m

DSP with Matlab by Proakis and Ingle

% Analog Signal

Dt = 0.00005;

t = -0.005:Dt:0.005;

xa = exp(-1000*abs(t));

%

% Continuous-time Fourier Transform

Wmax = 2*pi*2000;

K = 500; k = 0:1:K;

W = k*Wmax/K;

Xa = xa * exp(-j*t'*W) * Dt;

Xa = real(Xa);

W = [-fliplr(W), W(2:501)]; % Omega from -Wmax to Wmax

Xa = [fliplr(Xa), Xa(2:501)];

subplot(1,1,1)

subplot(2,1,1);plot(t*1000,xa);

xlabel('t in msec.'); ylabel('xa(t)')

title('Analog Signal')

subplot(2,1,2);plot(W/(2*pi*1000),Xa*1000);

xlabel('Frequency in KHz'); ylabel('Xa(jW)*1000')

title('Continuous-time Fourier Transform')