www.gusucode.com > 基于Matlab的MIMO通信系统仿真 含报告；司中威；了解移动通信 > 基于Matlab的MIMO通信系统仿真 含报告；司中威；了解移动通信关键技术，了解数字通信系统仿真流程，实现基本的信道编译码、调制解调等通信模块。（好评如潮，课设拿满） 学习并实现MIMO空时处理技术 学习性能分析的思路和方法/mimo/matlab for mimo 2x2/RF.m
function RF(real_ch,SNR_dB)
close all;
% If argument is omitted, the channel is simulated
if (nargin < 1)
real_ch = 0;
end
if (nargin <2)
SNR_dB = 20;
end
disp('-- Start RF --')
% Load the baseband channels
load('TXOutput');
% Load the global parameters
load('tx_param');
save('SimType','real_ch');
% Build the sent stream
S = [channel1_block; channel2_block];
% Output of the baseband channel
[Nr,Nc] = size(S);
Y = [];
% For plotting
h11 = zeros(1,Nc);
% ---------------------------------------------------
% Simulate a channel in baseband
% ---------------------------------------------------
if (real_ch == 0)
% Time-varying channel
step = 2*10^(-5);
% Channel Matrix
% H = [1 0; 1 0; 0 1; 0 1];
% H = sqrt(1/2)*ones(4,2);
% H = sqrt(1/2)*randn(4,2) + j*sqrt(1/2)*randn(4,2);
H = [ 0.5189 + 0.0943i 0.7957 - 0.0453i;
-1.1536 - 0.2596i -0.3614 - 0.7444i;
0.3960 - 0.7802i 0.6947 + 0.4259i;
0.8576 - 0.0625i -0.9832 - 0.3027i
];
%
% % Real channel
% H = 1/2 * [ 0.2223 + 0.2129i 0.0452 - 0.2562i
% 0.1307 + 0.2811i 0.1384 - 0.2228i
% 0.0035 - 0.0033i 0.0099 + 0.0217i
% 0.0046 - 0.0019i 0.0013 + 0.0240i ];
% Keep a recoed of all the channel matrices
H_var = zeros(4,2*frames_len);
% Proceed frame by frame
index = 1;
for fr=1:nr_frames
% Apply the channel matrix (MUI)
H = H + step*(sqrt(1/2)*randn(4,2) + j*sqrt(1/2)*randn(4,2));
H_var(:,2*fr-1:2*fr) = H;
% Number of previous frames
if mod(fr-1,4)==0
Y = [Y H*S(:,index:index+Lf_sync-1)];
index = index+Lf_sync;
else
Y = [Y H*S(:,index:index+Lf-1)];
index = index+Lf;
end
h11(index) = H(1,1);
end
save('ChannelMatrix','H_var');
% See page 6 to 11 in the DC Project Assignement
% Es_bb Energy of a symbol in baseband
Es_bb_th = 10 * norm(pulse_shape)^2/L;
% Es energy of a symbol in the upconverted signal
Es_th = Es_bb_th/2;
% SNR = Es/N0
% Where Sn(f) = N0/2 power spectral density of the real noise
N0 = Es_th / 10^(SNR_dB/10);
sigma_sqr_bb = 2*N0*L;
disp(['Theoritical Es: ', num2str(Es_th)])
disp(['Variance of the bb noise: ', num2str(sigma_sqr_bb)]);
disp(['Eb/N0 (SNR) ', num2str(10*log10(Es_th/4/N0))]);
% disp(['Es/N0 (SNR) ', num2str(10*log10(Es_th/N0))]);
% disp('');
disp(['SNR (bb) ', num2str(10*log10(Es_bb_th/sigma_sqr_bb))]);
% Uncorrelated noise
Noise = sqrt(sigma_sqr_bb/2) * ( randn(4,Nc) + j*randn(4,Nc) );
% Correlated noise
% Noise = sqrt(sigma_sqr_bb/2) * ( ones(4,1) * randn(1,Nc) + j * ones(4,1) *randn(1,Nc) );
Y_n = Y + Noise;
else
Y_n = S;
end
% ---------------------------------------------------
% Upconversion
% ---------------------------------------------------
N_channels = size(Y_n,1);
% Upconvert
for k=1:N_channels
Y_up(k,:) = upconv(real(Y_n(k,:)), imag(Y_n(k,:)), Fc_tx, Fs, 0);
end
% Add the sinusoid for frequency offset estimation
index = 0:time_end;
cosinus = 3*cos(2*pi*(Fc_tx/Fs)*index);
if (real_ch==0)
% Noise:
sigma_sqr = N0/2*L;
sigma = sqrt(sigma_sqr);
disp(['Variance of the real noise: ', num2str(sigma_sqr)]);
else
% For the real channel, don't add more noise for the tail and queue!
sigma = 0;
end
Y_R = [sigma * randn(N_channels,init_len), ones(N_channels,1)*cosinus, Y_up, sigma * randn(N_channels,tail_len)];
% ---------------------------------------------------
% Send through the real channel
% ---------------------------------------------------
if(real_ch == 1)
% Use the real channel
N = size(Y_R,2);
% Scaling to use full power
scaling = 1/(1.2*max(max(Y_R))) * 32766;
figure;
Nc = 2;
Nr = 2;
subplot(Nr,Nc,1);
plot(Y_R(1,:))
title('Channel 1 (Left)');
subplot(Nr,Nc,2);
plot(Y_R(2,:))
title('Channel 2 (Right)');
Y_R = Y_R * scaling;
[Xin,no_samples_delivered,buffer_size]=DSK6713_rxtx(N,2,2,Y_R,Fs);
% Scale down by the same factor used for scaling up
Xin = Xin/scaling;
N_out = size(Xin,2);
% Put Left in Y_R(1) and Right in Y_R(3)
Y_R = [Xin(1,:) ; zeros(1,N_out); Xin(2,:); zeros(1,N_out)];
subplot(Nr,Nc,3);
plot(Y_R(1,:))
title('Channel A [Y_R(1)] (Left)');
subplot(Nr,Nc,4);
plot(Y_R(3,:))
title('Channel B [Y_R(3)] (Right)');
end
save('ChannelOutput','Y_R');
disp('End')
% ---------------------------------------------------
% Plots
% ---------------------------------------------------
if (real_ch == 0)
figure;
Nc = 2;
Nr = 2;
subplot(Nc,Nr,1);
plot(real(S(1,:)));
title('Signal sent on ant. 1')
subplot(Nc,Nr,2);
plot(real(Y(1,:)));
hold on;
plot(real(Y_n(1,:)),'g');
legend('I rec. on ant. 1','Noisy I rec. on ant. 1');
subplot(Nc,Nr,3);
plot(Y_R(1,:))
title('Signal rec. on ant. 1')
subplot(Nc,Nr,4);
plot(abs(h11))
title('Magnitude of H11')
end