Cedric Roux
56c66c09aa
Pre-ci test passed git-svn-id: http://svn.eurecom.fr/openair4G/trunk@4000 818b1a75-f10b-46b9-bf7c-635c3b92a50f
89 lines
2.8 KiB
Matlab
89 lines
2.8 KiB
Matlab
function [CAP] = capacity_SU_MMSE(HH,SNR,normalize)
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
% [CAP] = capacity_SU_MMSE(HH,SNR)
|
|
%
|
|
% This function calculates the capacity of the channel assuming spatial
|
|
% multiplexing at the transmitter and a MMSE receiver. At the moment, we
|
|
% use as mant Tx antennas as there are Rx antenns. In the future, this
|
|
% function will use Alamouti coding if the number of Tx antenna exceeds
|
|
% the number of Rx antennas.
|
|
%
|
|
% The channel gains are normalized, such that E(|h_{i,j}|^2) = 1,
|
|
% where the avaraging is done over all snapshots and all frequencies.
|
|
%
|
|
% PARAMETERS
|
|
% - CAP is the capacity values;
|
|
% - HH is the input channel (M_Rx,M_Tx,fq,Channels)
|
|
% - SNR is the considered SNR (Linear)
|
|
% - normalize is a flag that indicates if the channel should be normalized
|
|
%
|
|
% Created: 25/04/2007 by delacerd@eurecom.fr
|
|
% Modified last: 12/12/2007 by florian.kaltenberger@eurecom.fr
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
[M_Rx,M_Tx,N_fq,N_channel] = size(HH);
|
|
|
|
% fk: I don't think this code is correct.
|
|
% tmp = zeros(N_fq,N_channel);
|
|
% for kk = 1:N_channel,
|
|
% tmp1 = 0;
|
|
% for ii = 1:N_fq,
|
|
% var1(:,:,ii,kk) = HH(:,:,ii,kk)*HH(:,:,ii,kk)';
|
|
% tmp1 = tmp1 + norm(var1(:,:,ii,kk),'fro');
|
|
% end
|
|
% PP = tmp1/N_fq;
|
|
% var1 = (M_Rx/PP) * var1;
|
|
% for ii = 1:N_fq,
|
|
% tmp(ii,kk) = abs(log2(det(diag(ones(M_Rx,1)) + SNR * var1(:,:,ii,kk))));
|
|
% ForPDF(ii,kk) = trace(M_Tx*var1(:,:,ii,kk));
|
|
% end
|
|
% end
|
|
|
|
if nargin<3
|
|
normalize = 1;
|
|
end
|
|
if normalize
|
|
% Normalization of H, such that E(|h_{i,j}|^2) = 1!
|
|
var1 = complex(zeros(M_Rx,M_Rx,N_fq,N_channel));
|
|
tmp = 0;
|
|
for ii = 1:N_fq,
|
|
for kk = 1:N_channel,
|
|
% this is the squared frobenious norm of HH
|
|
var1(:,:,ii,kk) = HH(:,:,ii,kk)*HH(:,:,ii,kk)';
|
|
tmp = tmp + trace(var1(:,:,ii,kk));
|
|
end
|
|
end
|
|
PP = real(tmp/(N_fq*N_channel*M_Rx*M_Tx))
|
|
else
|
|
PP = 1;
|
|
end
|
|
|
|
% HH = HH*sqrt(M_Rx*M_Tx/PP);
|
|
% now E(|h_{i,j}|^2) = 1!
|
|
|
|
% Capacity estimation
|
|
tmp = zeros(N_fq,N_channel);
|
|
% ForPDF = zeros(N_fq,N_channel);
|
|
|
|
% antenna selection:
|
|
% selecet the two tranmit antennas with the highest gains
|
|
HH = HH(:,1:M_Rx,:,:);
|
|
|
|
n_p=1/SNR;
|
|
|
|
for ii = 1:N_fq,
|
|
for kk = 1:N_channel,
|
|
tmp(ii,kk) = MISO_MMSE(HH(:,:,ii,kk)./PP,n_p,n_p);
|
|
end
|
|
end
|
|
|
|
% ForPDF = reshape(ForPDF,1,N_fq*N_channel);
|
|
|
|
if N_channel == 1, % if we are analyzing one single frame the output is a value
|
|
CAP = mean(tmp);
|
|
% CAP = (tmp);
|
|
else % if we are analyzing a sequence of frames, the output is a vector with all capacity values
|
|
CAP = reshape(tmp,1,N_fq*N_channel);
|
|
end
|
|
|