MATLAB: How to get Magnitude Spectrum of a Cosine Wave

Question

im trying to get magnitude spectrum of a cosine wave x(t)=cos(2*pi*fo*t),0<t<T; where fo=2000hz and sampling frequency Fs=32kHz.Also,samples need be generated at the rate of Fs over a time interval T. (signal length T has to be chosen such that there are 1024 samples of the simulated analog signal).

im not getting the correct spike…

Answer 1

Hi Upsesh,

This can be solved by properly using fft (Fast Fourier Transform)

I wrote a fftplot function wich plots the magnitude and returns the coeffs, I'll attach it here, have a look at it and you'll learn how to use FFT. I'll also attach a PDF file regarding how to use FFT.

Hope this helps.

Good Luck!