sinusoidal wave using mat lab

a) Synthetise a 400 Hz and 1200 Hz sinusoidal signal of 1 second duration at Fs = 8000Hz.

b) Use the sound command to hear both signals. Adjust the command using the appropriate Fs.

c) Find the magnitude spectrum of this signal using the DFT. Plot the magnitude spectral profiles using a k-axis, a f-axis in Hertzs and a T-axis in rad/samp.

d) Verify whether the spectral peaks appear at the right frequencies. Before taking the spectrum zero pad to the nearest power of two. Are there any other spectral peaks besides the 400Hz and the 1200Hz peaks. Explain.

e) Now look at the magnitude spectrum of the signal when you only use half of the signal to find its spectrum, then use aproximately 1/32 of the signal, 1/64, 1/512 and 1/1000 of the signal. Are the spectral peaks as sharp as before or do they become more "smeared" as less and less points are used? Discuss. Make sure you zero pad the truncated versions of the signal to at least 16384 points in order to have a smooth spectrum.

[Azzi Abdelmalek]

Gian, are you expecting someone to do your homework?