Power Spectral Density 

AIM: To verify Power Spectral Density

EQUIPMENTS:  

Operating System - Windows XP

Constructor - Simulator

Software - CCStudio 3 & MATLAB 7.5

PROGRAM:  

%Power spectral density  

t = 0:0.001:0.6;  

x = sin(2*pi*50*t)+sin(2*pi*120*t);  

y = x + 2*randn(size(t));  

subplot(2,1,1);

% figure(1);

plot(1000*t(1:50),y(1:50))  

title('Signal Corrupted with Zero-Mean Random Noise')  

xlabel('time (milliseconds)');  

Y = fft(y,512);  

%The power spectral density, a measurement of the energy at various frequencies, is:

Pyy = Y.* conj(Y) / 512;  

f = 1000*(0:256)/512;

subplot(2,1,2);

% figure(2);

plot(f,Pyy(1:257))  

title('Frequency content of y');

xlabel('frequency (Hz)');

OUTPUT:-

 RESULT:  The power spectral density   of given sequence  is obtained. Hence the theory and practical value are proved.

Outcome: At the end of the experiment the students are able to find the power spectral density   of given sequence  is obtained.

VIVA QUESTION:

? What do you mean by phase spectrum and magnitude spectrum/ give comparison?

? How do you reduce spectral leakage?

? What do you mean by spectral resolution?