I am what I am
Thursday, December 30, 2010
BER as a function of SNR in Rayleigh Channel
At times, finding the correct SNR (Signal to Noise Ratio) for the desired BER (Bit Error Rate) in a communication channel becomes a pain. Its easy to tell that the BER goes on improving as we increase the SNR level of the input signal before it makes out on the channel.
The Bit Error Probability is given as
where
The BER now is the function of the Probability Density Function and can be summed as the integral of the product of Bit Error Probability and probability density function.
If anyone does remember the Gaussian Distribution, the probability density function extends from the mid-half to either sides towards infinity. Applying similar theory we get,
where,
is the Probability density Function of and
is our Energy of the Bits to Noise Ratio or the plain old SNR would do. Now, I am not going much deeper into the integral calculations to find out what's the result going to be because I am weak at maths. But the result from the books would show the BER as
Anyways here is the catch. If you want to compare how these signals behave as a function of SNR in Rayleigh Channel or in plain old AWGN (Additive White Gaussian Noise) channel, here is the matlab code for it.
http://dl.dropbox.com/u/15048456/Final Code/task3.m
http://dl.dropbox.com/u/15048456/Final Code/rayleigh_modulator.m
Just put those files together in the same active or working directory while compiling and executing them. Watch and learn
Wednesday, December 29, 2010
Three Lions hunt down Kangaroos
Poor Aussies...feel good to see that Ashes now is where it should have been.
Saturday, November 20, 2010
Function for DFT Plot of Discrete Time Signal using Fast Fourier Transform Algorithm
function fftplot(signal_matrix, Fs)
%This function plots the two sided amplitude of the time varying signal
%sampled by frequency Fs
%Please note that this does not work if the two dimensional Image matrix is passed as signal_matrix.
%function to plot fft of the given signal
%input signal is passed in signal_matrix
%sampling frequency is given in Fs
signal_fft=fft(signal_matrix); %performing the fourier transform of the signal_matrix
Nx=length(signal_fft); % length of the FFT of signal
Ts=1./Fs; %Sample Period calculation
Fo= 1/(Ts*Nx); %frequency resolution factor
f=-Fs/2:Fo:(Fs/2)-1; %defining the range of the frequency that has to be plotted
figure;
plot(f,2*fftshift(abs(signal_fft./Nx))); %2 sided amplitude spectrum plot of the signal_matrix
%Function ends
%Save this function to the current MATLAB directory to use
%This function plots the two sided amplitude of the time varying signal
%sampled by frequency Fs
%Please note that this does not work if the two dimensional Image matrix is passed as signal_matrix.
%function to plot fft of the given signal
%input signal is passed in signal_matrix
%sampling frequency is given in Fs
signal_fft=fft(signal_matrix); %performing the fourier transform of the signal_matrix
Nx=length(signal_fft); % length of the FFT of signal
Ts=1./Fs; %Sample Period calculation
Fo= 1/(Ts*Nx); %frequency resolution factor
f=-Fs/2:Fo:(Fs/2)-1; %defining the range of the frequency that has to be plotted
figure;
plot(f,2*fftshift(abs(signal_fft./Nx))); %2 sided amplitude spectrum plot of the signal_matrix
%Function ends
%Save this function to the current MATLAB directory to use
Sunday, October 24, 2010
I am what I am
I am what I am
some tIme I am bad,
some tIme I am good
some tIme I act dumb,
some tIme I act clever
some tIme I cheat,
some tIme I am honest
every second, a dIfferent me....
I am what I am
Day dreamIng...lost In delusIons...waken up wIth the alarm...
always In hurry...never In tIme
that Is so much lIke me
so much lIke people judge about me
I am what I am...
Saturday, October 23, 2010
You know who I am
Folks,
If u want to know about me, then here I am:
Name: Prabhat Man Sainju
Age: 25
Sex: Male
Permanent Residence: Butwal-11, Lumbini Zone, Nepal
Education:
Bachelors Degree in Electronics and Communication Engineering
MS (RF Electronics), Tampere University of Technology (www.tut.fi)
Tampere, Finland
Interests:
- Advanced Mathematics
- Network Planning
- RF Filter Design
Hobbies:
- Football, cricket and any sort of game hitting balls
Contact:
- email: prabhat.sainju@tut.fi
- Cell: +358-417077314
Prabhat Man Sainju
Create your badge
Subscribe to:
Posts (Atom)