%% Simulation of Capacity of MIMO channel
% Author: alpswy
% Email: alpswy@gmail.com
% Revise History:
% 2009-08-22 Created
%% Parameters for normal simulation
ChanType = 'CorrRayleigh'; % AWGN, Rayleigh, CorrRayleigh, Rice
LOOP = 10000; % number of channel tap samples
const = 1/sqrt(2); % constant number
NT = 4; % number of receive antennas
NR = 4; % number of transmit antennas
SNRdB = 10; % SNR in dB
SNRdec = 10^(0.1*SNRdB); % SNR in decibel
%% Parameters for displaying
numGroup = 100; % variable used to count samples
Range_MIN = 0; % minimum value of figure
Range_MAX = 6; % maximum value of figure
%% Parameters for simulation of correlation of channel
rho_t = 0;
rho_r = 0;
%% Parameters for simulation of Rice channel
K = 1; % Rice factor
D = sqrt(K);
switch ChanType
case 'AWGN'
H = ones(NR, NT);
C = log2(det(eye(NR) + SNRdec/NT*(H*H')));
C_1 = [C, C];
plot(C_1, 0:1);
axis([Range_MIN, Range_MAX, 0, 1]);
case 'Rayleigh'
C = zeros(1, LOOP);
C_2 = zeros(1, numGroup);
for idx_LOOP = 1:LOOP
H = const*(randn(NR, NT) + 1j*randn(NR, NT));
C(idx_LOOP) = log2(det(eye(NR) + SNRdec/NT*(H*H')));
end
C_min = min(C);
C_max = max(C);
C_1 = hist(C, numGroup);
C_2(1) = C_1(1);
for idx = 2:numGroup
C_2(idx) = C_2(idx-1) + C_1(idx);
end
C_2 = C_2 / LOOP;
Range_MIN = C_min;
Range_MAX = C_max;
X_axe = Range_MIN + [0:(numGroup-1)]/numGroup*(Range_MAX-Range_MIN);
plot(X_axe, C_2);
case 'CorrRayleigh'
C = zeros(1, LOOP);
C_2 = zeros(1, numGroup);
R_tx = [1, rho_t; rho_t, 1];% for 2*2 only
R_rx = [1, rho_r; rho_r, 1];
for idx_LOOP = 1:LOOP
H = const*(randn(NR, NT) + 1j*randn(NR, NT));
H_Corr = R_rx * H * R_tx;
C(idx_LOOP) = log2(det(eye(NR) + SNRdec/NT*(H_Corr*H_Corr')));
end
C_min = min(C);
C_max = max(C);
C_1 = hist(C, numGroup);
C_2(1) = C_1(1);
for idx = 2:numGroup
C_2(idx) = C_2(idx-1) + C_1(idx);
end
C_2 = C_2 / LOOP;
Range_MIN = C_min;
Range_MAX = C_max;
X_axe = Range_MIN + [0:(numGroup-1)]/numGroup*(Range_MAX-Range_MIN);
plot(X_axe, C_2);
case 'Rice'
C = zeros(1, LOOP);
C_2 = zeros(1, numGroup);
for idx_LOOP = 1:LOOP
H = const*(randn(NR, NT) + 1j*randn(NR, NT)) + D * ones(NR, NT);
C(idx_LOOP) = log2(det(eye(NR) + SNRdec/NT*(H*H')));
end
C_min = min(C);
C_max = max(C);
C_1 = hist(C, numGroup);
C_2(1) = C_1(1);
for idx = 2:numGroup
C_2(idx) = C_2(idx-1) + C_1(idx);
end
C_2 = C_2 / LOOP;
Range_MIN = C_min;
Range_MAX = C_max;
X_axe = Range_MIN + [0:(numGroup-1)]/numGroup*(Range_MAX-Range_MIN);
plot(X_axe, C_2);
otherwise
disp('Other Channel Type is still under construction. Only AWGN and Rayleigh fading is available.')
keyboard
end
