gnoise.m

经典书籍MIMO Signals And Systems的源代码

function gn = gnoise(sig, leng, limit)

% Function gnoise generates Gaussian
% distributed samples with
% standard deviation sigma (variable:'sig')
% Vector length is controlled
% by parameter 'leng'
% Noise values >= limit are replaced by
% value "limit". 

gn = sig*sqrt(-2 *log(rand(1,leng))).*cos(2*pi*rand(1,leng));

% If three input parameters specified, then 
% activate limiter.
if nargin==3
   fi=find(gn > limit);
   gn(fi)=limit*ones(1,length(fi));
   fi=find(gn < -limit);
   gn(fi)=-limit*ones(1,length(fi));
end