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openairinterface5g/openair1/EMOS/MATLAB/capacityEMOS.m
T
2013-06-25 09:05:02 +00:00

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2.7 KiB
Matlab
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function [CAP] = capacityEMOS(HH,SNR,normalize)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% [CAP] = capacityEMOS(HH,SNR) %%
% %%
% This function was build to calculate the capacity %%
% of the estimated EMOS channels. It first normalizes %%
% the channel gains, such that E(|h_{i,j}|^2) = 1, %%
% where the avaraging is done over all snapshots and %%
% all frequencies. %%
% - [CAP] is the capacity values; %%
% - HH is the input channel (M_Rx,M_Tx,fq,Channels) %%
% - SNR is the considered SNR (Linear) %%
% %%
% Created: 25/04/2007 by delacerd@eurecom.fr %%
% Modified last: 10/10/2007 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 frobenious norm of HH
var1(:,:,ii,kk) = HH(:,:,ii,kk)*HH(:,:,ii,kk)';
tmp = tmp + trace(var1(:,:,ii,kk));
end
end
PP = tmp/(N_fq*N_channel);
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);
for ii = 1:N_fq,
for kk = 1:N_channel,
% the following two lines are the same, the second one should be
% more efficient
tmp(ii,kk)=abs(log2(det(diag(ones(M_Rx,1)) + (SNR/M_Tx) * HH(:,:,ii,kk) * HH(:,:,ii,kk)')));
% tmp(ii,kk)=abs(log2(det(diag(ones(M_Rx,1)) + (M_Rx*SNR/PP) *
% var1(:,:,ii,kk))));
% ForPDF(ii,kk) = trace(M_Tx*var1(:,:,ii,kk));
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