mimo_de.m

AWGN for MIMO and fading

% STTD MIMO decoder and demodulator

function [z] = mimo_de(Rx,M,y,num_Tx)

% z : estimated sysbol

% variable in MIMO
% R = zeros(L/bit_n, 1);
% 
% Rx_11 = Rx_1(1:2:end);      % 盲澄 1阑 芭模 圈荐锅掳 单捞磐
% Rx_12 = Rx_1(2:2:end);      % 盲澄 1阑 芭模 娄荐锅掳 单捞磐
% Rx_21 = Rx_2(1:2:end);      % 盲澄 2甫 芭模 圈荐锅掳 单捞磐
% Rx_22 = Rx_2(2:2:end);      % 盲澄 2甫 芭模 娄荐锅犁 单捞磐
% 
% % 窍唱狼 救抛唱俊辑 矫埃喊肺 罐绰 荐脚 单捞磐
% r_1 = Rx_11 + Rx_21;
% r_2 = Rx_12 + Rx_22;
% 
% % estimation data
% R(1:2:end, :) = (r_1 + conj(r_2))/2;
% R(2:2:end, :) = (r_1 - conj(r_2))/2;
% 
% % Tx_noisy = awgn(Tx, snr, 'measured');
% % ynoisy = awgn(y, snr, 'measured');
% scale = modnorm(y, 'peakpow', 1);
% % scatterplot(y);
% % scatterplot(R.*scale);
% 
% 
% % hold on;
% % axis([-1.5 1.5 -1.5 1.5]);
% % hold off;
% 
% RR = R./scale;
% b = modem.qamdemod('M', M, 'SymbolOrder', 'Gray');
% z = demodulate(b, RR);
% 

scale = modnorm(y, 'avpow', 1/num_Tx);

rr = Rx/scale;
b = modem.qamdemod('M', M, 'SymbolOrder', 'Gray');
z = demodulate(b, rr);