www.gusucode.com > DS-cdma仿真matlab程序 > code8/cdma/fade_fs.m
%*********************************************************** % This mfunction generates frequency selective % Rayleigh fading % % AUTHOR: Wenbin Luo % DATE : 05/02/01 % % FUNCTION SYNOPSIS: % y = fade_fs(x,L) % % Parameter Description: % y : output signal % x : input signal % L : number of independent Rayleigh % fading process %********************************************************** function y = fade_fs(x,L) % Generate bivariate Gaussian uncorrelated % random variables tmp1 = 0:1:(L-1); tmp1 = exp(-tmp1); tmp(1:2:2*L-1) = tmp1; tmp(2:2:2*L) = tmp1; mu = zeros(1,2*L); C = 0.5*diag(tmp); x_len = length(x); r = mvnrnd(mu,C,x_len); % Convert to polar coordinates and compute magnitude x = x(:); y = zeros(x_len,1); for i = 1:L, z = r(:,2*i-1) + j*r(:,2*i); env = abs(z); %phi = angle(z); tmp_y = env.*x; tmp_y = [zeros(i-1,1); tmp_y(1:x_len-i+1)]; y = y + tmp_y; end %**********************************************************