how to use matlab code tp plot following

(a) plot s(t) and its magnitude frequency spectrum

(b) plot the modified signal x(t)=s(t)*cos(2πfct) in both time and frequency spectrum.

(c) Assuming a perfect coherent demodulation, plot the output (in time and magnitude spectrum) of the demodulator mixer.

(d) Plot the output (in time and magnitude spectrum) of the ideal low pass filters with bandwidth of 1Hz and 5Hz respectively.

(e) Repeat parts(c) and (d) assuming a non-ideal mixer with phase error of 5 degree

(f) Repeat parts(c) and (d) assuming a non-ideal mixer with phase error 0.2Hz

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer

[Walter Roberson]

s(t) = mod(ceil(t), 2) * 2 - 1;

Answer 1

[Image Analyst]

Hints:

t = linspace(0, 4, 1000);
x = s .* cos(2 * pi * f * c * t)

Function hints: plot(), linspace(), fft() or pwelch(), abs(), real(), imag(), etc.