plotspectrum.m

using Jakes model to simulate rayleigh channel fading

%%%%%%%%%%%%%    Plot Spectrum      %%%%%%%%%%%%%%% 
function Plot_Spectrum=PlotSpectrum(input,width) 
 
%%%%  width       % width of the siginal [s] 
%%%%  input       % samples of the siginal  
points =length(input);     % number of samples 
dt = width/points;       % sampling period 
 
signal= zeros(1,1*points); 
signal(1:points)=input; 
 
% ----------------------------- 
% Step - Calculate 
% ----------------------------- 
fs = 1/dt;         
N = length(signal);   
T = N * dt;          
df = 1/T;         
 
X = fft(signal);  
X = X/N;          
mPSD= abs(X).^2/(df^2);     
PSD=fftshift(mPSD); 
PSD=(1/T).*PSD; 
 
% ----------------------------- 
% Step - Plot 
% ----------------------------- 
figure(6); 
frequency=linspace(-fs/2,fs/2,length(PSD)); 
PF=semilogy(frequency,PSD); 
grid on; 
%axis([-5e9 5e9 0 5e-9]); 
T=title('Frequency domain'); 
set(T,'FontSize',14); 
X=xlabel('Frequency [Hz]'); 
set(X,'FontSize',14); 
Y=ylabel('Double-Sided ESD  [V^2/Hz]'); 
set(Y,'FontSize',14); 
hold on;