generaterayleighfade.m

simulation module for visual wireless sensor network

function [fadeEnvelope] = GenerateRayleighFade(NumSamples, AvgPower, numCoeffts, denCoeffts)

% First generate the I and Q Gaussian Sequences.
I_Gaussian = randn(1,NumSamples);
Q_Gaussian = randn(1,NumSamples);

% Pass the samples thro a spectral shaping filter.
If_Gaussian = filter(numCoeffts, denCoeffts, I_Gaussian, randn);
Qf_Gaussian = filter(numCoeffts, denCoeffts, Q_Gaussian, randn);

% Generate the Fade Envelope.
fadeEnvelope = sqrt(If_Gaussian.*If_Gaussian + Qf_Gaussian.*Qf_Gaussian);

% Adjust the fade power level to the one specified.
rmsEnvelope = sqrt(mean(fadeEnvelope.*fadeEnvelope));
fadeEnvelope = fadeEnvelope/rmsEnvelope;
fadeEnvelope = fadeEnvelope*sqrt(AvgPower);