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模拟DFE结构-DFE原理

已有 338 次阅读| 2023-11-27 21:17 |个人分类:SERDES|系统分类:其他

回复 rochesterlmg 2023-11-29 21:45: fe =

  -0.000000000000000 1.250000000000000 0.000000000000000

fb =

0.750000000000000

actual_isi =

               0 0.800000000000000 0.600000000000000

>> conv(fe,actual_isi)

ans =

               0  -0.000000000000000 1.000000000000000 0.750000000000000 0.000000000000000

回复 rochesterlmg 2023-11-29 21:59: N=1500;             % length of the information sequence
K=2;
actual_isi=[0.0 0.8 0.6 ];
tic;

% the information sequence
for i=1:N,
if (rand<0.5),
   info(i)=-1;
else
   info(i)=1;
end;

end;

% the channel output
y1=filter(actual_isi,1,info);
delay=0;
y=[y1(delay+1:end) zeros(1,delay)];
% Now the equalization part follows.
fe=[0  1 0 ]; % initial estimate of ISI
fb=0;
delta=0.1;
d_k=0;
for k=1:N-K,
y_k=y(k:k+K);

if 0%(bitand(k<=500,1) )% only update conefficient of ffe part during traing stage
   z_k=fe*y_k.';

   if (z_k<0),
      d_k=-1;
   else
         d_k=1;
   end
   e_k=d_k-z_k;
   fe=fe+delta*e_k*y_k;
   mse(k)=e_k^2;
   if k==500
      fe
      fb
   end
else%update conefficient of ffe and dfe during DD stage
   z_k=fe*y_k.'-fb*d_k;%+
   if (z_k<0),
      d_k=-1;
   else
         d_k=1;
   end

   e_k=d_k-z_k;
   fe=fe+delta*e_k*y_k;
   fb=fb+delta*e_k*d_k;%-
   mse(k)=e_k^2;
end

end

plot(mse);