Thread: matlab modulation schemes...

Hi im looking for some help with matlab im new to it and have to compare modulation schemes using Matlab. My model should create a data stream, modulate the data with a variety of modulation schemes e.g AM, FM, PSK, FSK, QAM, OFDM and pass the data through a noisy channel, demodulate the data and measure the performance based on a wireless channel...

I found the following code on creating noise using the randn function but would awgn do the same thing?

x = 0:0.01:2;
noise = 0.02*randn(size(x));
y = 5*x.*exp(-3*x) + noise;
plot(x,y,'o');
xlabel('x (arbitrary units)');
ylabel('y (arbitrary units)');
title('Plot of y = 5*x*exp(-3*x) + noise');

Originally Posted by dingdangdoo

Hi im looking for some help with matlab im new to it and have to compare modulation schemes using Matlab. My model should create a data stream, modulate the data with a variety of modulation schemes e.g AM, FM, PSK, FSK, QAM, OFDM and pass the data through a noisy channel, demodulate the data and measure the performance based on a wireless channel...

I found the following code on creating noise using the randn function but would awgn do the same thing?

x = 0:0.01:2;
noise = 0.02*randn(size(x));
y = 5*x.*exp(-3*x) + noise;
plot(x,y,'o');
xlabel('x (arbitrary units)');
ylabel('y (arbitrary units)');
title('Plot of y = 5*x*exp(-3*x) + noise');

y=awgn(signal,snr)

will add Gaussian white noise to signal with the given snr in dB (according to the documentation anyway).

CB