fsedez.m

qam的matlab程序。m文件

%fsedez.m
%fse design
%crj jr, 3/03

clear

%channel specification 
%need number of coefficients to be a factor of 4
d0=[1,0.1,-0.1,-0.5,-0.1,0.05,-0.01,0.01]';
d1=[1,0.8,1.025,1.2975,0.4646,0.2339,0.0706,0.02]';
d2=[1,0.8,1.665,1.8095,1.11207,1.0643,0.368,0.1696,...
	  0.0452,0.0127,0.001,0.0002]';
d3=[1,-0.4,0.52,-0.256,-0.0768,0,0.001,-0.001]';
load charp1;
charp1=charp1(:,1);

%channel selection
%d=d3;
d=charp1;

%inverse SNR selection
%L=0.01;
L=0;

%equalizer length selection
%el=length(d);
%el=4*length(d);
el=round(0.5*length(d));

%convolution matrix construction
D=convmtx(d,el);

%row-decimation
Deven=D(1:2:length(D),:);
Dodd=D(2:2:length(D),:);

%optimal g and delay selection
DDeven=Deven'*Deven+L*eye(size(Deven'*Deven));
DDodd=Dodd'*Dodd+L*eye(size(Dodd'*Dodd));

goptmate=pinv(DDeven)*Deven';
goptmato=pinv(DDodd)*Dodd';

[MMSEeven,optinde]=...
   min(abs(diag(eye(size(Deven*goptmate))-Deven*goptmate)))
[MMSEodd,optindo]=...
   min(abs(diag(eye(size(Dodd*goptmato))-Dodd*goptmato)))

gopte=goptmate(:,optinde);
gopto=goptmato(:,optindo);

%channnel-equalizer baud-spaced combination
gesube=goptmate(1:2:size(goptmate,1),optinde);
gesubo=goptmate(2:2:size(goptmate,1),optinde);
gosube=goptmato(1:2:size(goptmato,1),optindo);
gosubo=goptmato(2:2:size(goptmato,1),optindo);
dsube=d(1:2:length(d));
dsubo=d(2:2:length(d));
oce=(conv(dsube,gosubo)+conv(dsubo,gosube))'
ece=[conv(dsube,gesube)',0]+[0,conv(dsubo,gesubo)']

figure(1)
clf
zplane([],roots(d))
title('channel zeros')

figure(2)
clf
stem(d)
title('channel impulse response')

figure(3)
clf
stem(gopte)
title('optimal (even) equalizer impulse response')

figure(4)
clf
stem(gopto)
title('optimal (odd) equalizer impulse response')

figure(5)
clf
freqz(d,1)
title('channel frequency response')

figure(6)
clf
freqz(gopte,1)
title('optimal (even) equalizer frequency response')

figure(7)
clf
freqz(gopto,1)
title('optimal (odd) equalizer frequency response')

figure(8)
clf
freqz(ece,1)
title('combined channel (even) equalizer frequency response')

figure(9)
clf
freqz(oce,1)
title('combined channel (odd) equalizer frequency response')