%?multi_user_MIMO.m
clear?all;?clc;?clf
mode=1;?%?Set?0/1?for?channel?inversion?or?regularized?channel?inversion
N_frame=20?
N_packet=80?%?Number?of?frames/packet?and?Number?of?packets
b=2?%?
NT=2?%?No?of?Tx?Antennas
N_user=2?%?Total?users
N_act_user=2?%Active?users?are?4
I=eye（N_act_userNT）?%?4?x?4?Eye?matrix?generation?（Active?users?x?Tx?Antennas）
N_pbits?=?N_frame*NT*b?%?Number?of?bits?in?a?packet
N_tbits?=?N_pbits*N_packet?%?Number?of?total?bits
SNRdBs?=?[0:5:30]?%?SNR?range
sq2=sqrt（2）??%?square?root?of?2
for?i_SNR=1:length（SNRdBs）
SNRdB=SNRdBs（i_SNR）?;
N_ebits?=?0?;
rand（‘seed‘1）?;
randn（‘seed‘1）;
sigma2?=?NT*0.5*10^（-SNRdB/10）?;
sigma?=?sqrt（sigma2）;
for?i_packet=1:N_packet
msg_bit?=?randint（1N_pbits）;?%?Bit?generation
symbol?=?QPSK_mapper（msg_bit）.‘?;%?bits?to?symbols
x?=?reshape（symbolNTN_frame）;?%?arranging?sysmbols
for?i_user=1:N_user
H（i_user:）?=?（randn（1NT）+j*randn（1NT））/sq2;?%?ith?user?channel?（one?by?one）
Channel_norm（i_user）=norm（H（i_user:））;?%?norm?calculation?（one?by?one）
end
[Ch_normIndex]=sort（Channel_norm‘descend‘）;
H_used?=?H（Index（1:N_act_user）:）;
temp_W?=?H_used‘*inv（H_used*H_used‘+（mode==1）*sigma2*I）;
beta?=?sqrt（NT/trace（temp_W*temp_W‘））;?%??Beta=underroot（No?of?tx?antannas/trace?of?inv（H）*（inv（H））^H
W?=?beta*temp_W;???%??Beta?into?MMSE?matrix?it?is?used?to?distribute?equal?power?to?tx?antennas
Tx_signal?=?W*x;?%?Pre-equalized?signal?at?Tx
%%%%%%%%%%%%%?Channel?and?Noise?%%%%%%%%%%%%%
Rx_signal?=?H_used*Tx_signal?+?...
sigma*（randn（N_act_userN_frame）+j*randn（N_act_userN_frame））;
%%%%%%%%%%%%%%?Receiver?%%%%%%%%%%%%%%%%%%%%%
x_hat?=?Rx_signal/beta;??%Rx?signal?is?divided?by?Beta
symbol_hat?=?reshape（x_hatNT*N_frame1）;
symbol_sliced?=?QPSK_slicer（symbol_hat）;
demapped=QPSK_demapper（symbol_sliced）;
N_ebits?=?N_ebits?+?sum（msg_bit~=demapped）;
end
BER（i_SNR）?=?N_ebits/N_tbits
end
semilogy（SNRdBsBER‘-o‘‘LineWidth‘2）?grid?on

?屬性????????????大小?????日期????時間???名稱
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?????文件???????1945??2012-10-19?08:41??Matrix_inversion_Multiuser_MIMO\Matrix_inversion_Pre_coding_debug.m

?????文件????????214??2012-10-04?10:12??Matrix_inversion_Multiuser_MIMO\QPSK_demapper.m

?????文件????????198??2012-10-04?10:10??Matrix_inversion_Multiuser_MIMO\QPSK_mapper.m

?????文件????????282??2012-10-04?10:11??Matrix_inversion_Multiuser_MIMO\QPSK_slicer.m

?????目錄??????????0??2012-10-19?08:42??Matrix_inversion_Multiuser_MIMO

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?????????????????2639????????????????????5