M.zip_Alamouti_BER.m_BER曲线_matlab BER_qpsk 性能曲线

% Simulation BER of QPSK Alamouti STBC with two transmit and receive antenna %In this discussion, we will assume that the channel is a flat fading Rayleigh multipath channel and the modulation is QPSK. %All of This Code was Written by Mostafa Amin-Naji 2017/08/01 % Symorder of simoulation is for 'bin' and 'gray'; % For contact me: [email protected] % My Website: Amin-Naji.com clc clear close all; % % symorder='gray'; % 'bin' or 'gray' SNR_Range=0:2.5:12.5; %bits per symbol b=2; for ii=1:length(SNR_Range) SNR=SNR_Range(ii); num_errors=200; cycle = 0; error_num_bin=0; error_num_gray=0; error_num_normal=0; h = waitbar(0,'1','Name','Mostafa Amin-Naji Adv. Comm.'); avrage_p_y11=0; avrage_p_y21=0; avrage_p_y12=0; avrage_p_y22=0; avrage_p_n1t1=0; avrage_p_n1t2=0; avrage_p_n2t1=0; avrage_p_n2t2=0; s=1; while ((error_num_bin<num_errors) ) s=s+1; %bits bitsnumber=4; %QPSK M=4; x = randi([0 M-1],bitsnumber/2,1); % Random symbols symbol_bin = pskmod(x,M,pi/4,'bin'); symbol_gray = pskmod(x,M,pi/4,'gray'); symbol_normal=symbol_bin; %H H11=((randn(1,1))+1i*(randn(1,1)))./sqrt(2); H12=((randn(1,1))+1i*(randn(1,1)))./sqrt(2); H21=((randn(1,1))+1i*(randn(1,1)))./sqrt(2); H22=((randn(1,1))+1i*(randn(1,1)))./sqrt(2); %Noise N11=((randn(1,1))+1i*(randn(1,1)))./sqrt(2); N12=((randn(1,1))+1i*(randn(1,1)))./sqrt(2); N21=((randn(1,1))+1i*(randn(1,1)))./sqrt(2); N22=((randn(1,1))+1i*(randn(1,1)))./sqrt(2); for z=1:bitsnumber/4 x1_bin=symbol_bin(2*z-1,1); x2_bin=symbol_bin(2*z,1); x1_gray=symbol_gray(2*z-1,1); x2_gray=symbol_gray(2*z,1); x1_normal=symbol_normal(2*z-1,1); x2_normal=symbol_normal(2*z,1); % sigma=sqrt(((10^((SNR/10))))/2); H11(z)=sigma.*H11(z); H12(z)=sigma.*H12(z); H21(z)=sigma.*H21(z); H22(z)=sigma.*H22(z); Y11_bin=H11.*x1_bin+H12.*x2_bin+N11; Y12_bin=H21.*x1_bin+H22.*x2_bin+N12; Y21_bin=H11.*(-conj(x2_bin))+(H12.*conj(x1_bin))+N21; Y22_bin=H21.*(-conj(x2_bin))+H22.*conj(x1_bin)+N22; Y11_gray=H11.*x1_gray+H12.*x2_gray+N11; Y12_gray=H21.*x1_gray+H22.*x2_gray+N12; Y21_gray=H11.*(-conj(x2_gray))+(H12.*conj(x1_gray))+N21; Y22_gray=H21.*(-conj(x2_gray))+H22.*conj(x1_gray)+N22; Y1_normal=H11.*x1_normal+N11; Y2_normal=H22.*x2_normal+N22; Y_normal(1,1)=Y1_normal; Y_normal(2,1)=Y2_normal; end %++++++++++++++++++++++++++++++++++++++++ avrage_p_y11=abs(Y11_gray)^2+avrage_p_y11; avrage_p_y21=abs(Y21_gray)^2+avrage_p_y21; avrage_p_y12=abs(Y12_gray)^2+avrage_p_y12; avrage_p_y22=abs(Y22_gray)^2+avrage_p_y22; avrage_p_n1t1=avrage_p_n1t1+abs(N11)^2; avrage_p_n1t2=avrage_p_n1t2+abs(N12)^2; avrage_p_n2t1=avrage_p_n2t1+abs(N21)^2; avrage_p_n2t2=avrage_p_n2t2+abs(N22)^2; L=length(Y11_bin)*2; % s1_bin(1,1)=(conj(H11(z)).*Y11_bin(z)+H12(z).*conj(Y21_bin(z))+conj(H21(z)).*(Y12_bin(z))+H22(z).*conj(Y22_bin(z))); s1_bin(2,1)=(conj(H12(z)).*Y11_bin(1,z)-H11(z).*conj(Y21_bin(z))+conj(H22(z)).*(Y12_bin(z))-H21(z).*conj(Y22_bin(z))); s1_gray(1,1)=(conj(H11(z)).*Y11_gray(z)+H12(z).*conj(Y21_gray(z))+conj(H21(z)).*(Y12_gray(z))+H22(z).*conj(Y22_gray(z))); s1_gray(2,1)=(conj(H12(z)).*Y11_gray(1,z)-H11(z).*conj(Y21_gray(z))+conj(H22(z)).*(Y12_gray(z))-H21(z).*conj(Y22_gray(z))); output_qpsk_alamouti_bin = pskdemod(s1_bin,M,pi/4,'bin'); % output_qpsk_bin = pskdemod(s1_bin,M,pi/4,'bin'); output_qpsk_alamouti_gray = pskdemod(s1_gray,M,pi/4,'gray'); % output_qpsk_gray = pskdemod(s1_gray,M,pi/4,'gray'); output_qpsk_normal = pskdemod(Y_normal,M,pi/4,'bin'); waitbar(error_num_bin / num_errors,h,sprintf('calculating BER for SNR= %d',SNR)) % Check symbol error rate. [num_bin,~] = biterr(x,output_qpsk_alamouti_bin); [num_gray,~] = biterr(x,output_qpsk_alamouti_gray); [num_normal,~] = biterr(x,output_qpsk_normal); error_num_bin = error_num_bin + num_bin; error_num_gray = error_num_gray + num_gray; error_num_normal = error_num_normal + num_normal; cycle = cycle+4; end BER_alamouti_bin=error_num_bin/cycle BER_alamouti_gray=error_num_gray/cycle BER_normal=error_num_normal/cycle delete(h) Final_BER_alamouti_bin(ii)=BER_alamouti_bin; Final_BER_alamouti_gray(ii)=BER_alamouti_gray; Final_BER_normal(ii)=BER_normal; avarage_p_y=(avrage_p_y11+avrage_p_y21+avrage_p_y12+avrage_p_y22)/8; avrage_p_n=(avrage_p_n2t2+avrage_p_n1t1+avrage_p_n2t1+avrage_p_n1t2)/8; SNR_db(1,ii)=10*log10((avarage_p_y-avrage_p_n)/avrage_p_n) end figure (1), clf semilogy(SNR_Range,Final_BER_alamouti_bin,'b') hold on semilogy(SNR_Range,Final_BER_alamouti_gray,'r') % semilogy(SNR_Range,Final_BER_normal,'g') axis([SNR_Range([1 end]) 1e-5 1e0]); grid on; xlabel('SNR'); ylabel('BER') % figure % SNRs=0:2.5:12.5; % ber = berfading(SNRs/2,'PSK',4,2); % semilogy(SNRs/2,ber); % bertool