adslout.m

blind 多径信道中盲信道均衡的恒模算法

function [r,x] = adslout(h,sx,sn,iter,b)
% [r,x] = adslout(h,sx,sn,iter,b)
%     r = received data sequence (noisy channel output)
%     h = transmission channel, unit norm assumed
%     ssx = input signal power
%     ssn = noise power
%     iter = number of symbols to generate
%
%     b = 256-vector containing bit rate assignment
%     If b is not given, 4-QAM constellations are used per carrier
%     [this is not actually used in the current version]
%
%     generates ADSL-like data
%     (not yet 100% standard compliant)
%     This version taken from FRODO/MERRY files on 05/20/2002
%     Written by Rick Martin, last updated on 06/20/2002
%     Cornell University Blind Equalization Research Group
%
%     Copyright 2002 Cornell University, All Rights Reserved
%
%     SOFTWARE shall mean "adslout.m", Cornell Research Foundation
%     ("CRF") Docket D-3006.  SOFTWARE is made available to allow
%     non-commercial and research use of SOFTWARE.  Cornell
%     University specifically reserves all commercial rights to
%     SOFTWARE and these rights may be licensed by CRF on behalf
%     of Cornell University to third parties.
%
%     CRF provides SOFTWARE on an ``as is'' basis.  CRF does not
%     warrant, guarantee, or make any representations regarding
%     the use or results of SOFTWARE with respect to its
%     correctness, accuracy, reliability or performance.  The
%     entire risk of the use and performance of SOFTWARE is
%     assumed by EVALUATOR.  ALL WARRANTIES INCLUDING, WITHOUT
%     LIMITATION, ANY WARRANTY OF FITNESS  FOR A PARTICULAR
%     PURPOSE OR MERCHANTABILITY ARE HEREBY EXCLUDED.

N = 512;   % FFT size
nu = 32;   % CP length
S = N+nu;  % symbol length

if nargin < 5, b = 2*ones(N,1); end;

% 4-QAM data
X = sx/sqrt(2)*( 2*floor(2*rand(N/2,iter))-1 ) + ...
  j*sx/sqrt(2)*( 2*floor(2*rand(N/2,iter))-1 );

% Take IFFT, convert P/S, and add CP
x = zeros(1,S*iter);
datain = zeros(N,1);
for k=1:iter
   %datain([2:27,39:64]) = X(:,k);
   datain = i2r(X(:,k).');
   x(S*(k-1)+[nu+1:S]) = real(ifft(datain));
   x(S*(k-1)+[1:nu]) = x(S*(k-1)+[N+1:S]);  % copy into CP
end

% received signal
r = conv(x,h);
r = r(1:S*iter) + sn*randn(1,S*iter);