ploteye.m

绘制眼图的matlab程序,可以用于通信系统中传输质量的监测。

function [T,EyeSig]=ploteye(s,ups,offset);
%----------------------------------------------
%Function to plot eye diagram of s
%
%Inputs
%   s-real signal
%   ups-oversample rate
%----------------------------------------------
if(nargin < 3),offset=0;end
s=interp(s,4);
ups=ups*4;
f=mod(length(s),ups);
s=real(s(f+1+offset:end-(ups-offset)));


%------------------------------------------------
EyeSigRef=reshape(real(s),ups,length(s)/ups);
EyeSigm1=EyeSigRef(ups/2+2:ups,1:end-2);
EyeSig0=EyeSigRef(:,2:end-1);
EyeSigp1=EyeSigRef(1:ups/2,3:end);
EyeSig=[EyeSigm1;EyeSig0;EyeSigp1];

T=[-1+1/(ups):1/(ups):+1-1/(ups)];
plot(T,EyeSig),xlabel('Symbol periods'),ylabel('Amplitude');