aed.rar_H.R.H.

%------------------------------------------------------------------------ %Author: Milad Ehtesham milad.ehtesham@gmail.com %------------------------------------------------------------------------ %Refrences: %-- V.Tarokh,H. Jafarkhani,and A. R. Calderbank "Space-Time Codes from %Orthogonal Designs",IEEE Trans. Inform. Theory VOL. 45,NO. 5,JULY 1999. %-- Lizhong Zheng,and David N. C. Tse "Diversity and Multiplexing: A %Fundamental Tradeoff in Multiple-Antenna Channels",IEEE Trans. Inform. %Theory VOL. 49, NO. 5, MAY 2003. %-- V. Tarokh, H. Jafarkhani and A. R. Calderbank, ※Space-time block coding %for wireless communications: performance results§, IEEE J. Select. Areas %Commun., vol. 17, no. 3,pp. 451每460, Mar. 1999. %-- B. Vucetic and J. Yuan "space-time coding",John Wiley & Sons,2003. %------------------------------------------------------------------------ %NOTES: %About entering matrix O: %-- O is Tp*Nt matrix,as default 4*3 complex orthogonal is defined (rate 3/4). %for [x1 -x2 -x3;x2* x1* 0;x3* 0 x1*;0 -x3* x2*] -----enter------> O=[1 -2 -3;2+j 1+j 0;3+j 0 1+j;0 -3+j 2+j]; %-- Alamouti Scheme: [x1 x2;-x2* x1*] -----enter------> O=[1 2;-2+j 1+j]; %-- A real orthogonal: [x1 x2;-x2 x1] -----enter------> O=[1 2;-2 1]; %-- For real orthogonal matrices define M_psk=2; as real signal constellation. %-- O=[1]; is uncoded (no diversity). %-- In this program entries of O cannot be like "a1*x1[*]+a2*x2[*]+...+an*xn[*]" only they can be like "x1 or -x1 or x1* or -x1*". %------------------------------------------------------------------------ clear all O=[1 -2 -3;2+j 1+j 0;3+j 0 1+j;0 -3+j 2+j]; %Complex or Real Orthogonal Matrix **define this** Nt=size(O,2); %Number of Transmit antennas co_time=size(O,1); %Block time length Nr=1; %Number of Receive antennas **define this** Nit=100000; %Number of repeates for each snr **define this** M_psk=4; %M-PSK constellation,M_psk=2^k **define this** snr_min=3; %Min snr range for simulation **define this** snr_max=15; %Max snr rande for simulation **define this** graph_inf_bit=zeros(snr_max-snr_min+1,2); %Plot information graph_inf_sym=zeros(snr_max-snr_min+1,2); %Plot information num_X=1; num_bit_per_sym=log2(M_psk); for cc_ro=1:co_time for cc_co=1:Nt num_X=max(num_X,abs(real(O(cc_ro,cc_co)))); end end co_x=zeros(num_X,1); for con_ro=1:co_time %Compute delta,epsilon,eta and conj matrices for con_co=1:Nt if abs(real(O(con_ro,con_co)))~=0 delta(con_ro,abs(real(O(con_ro,con_co))))=sign(real(O(con_ro,con_co))); epsilon(con_ro,abs(real(O(con_ro,con_co))))=con_co; co_x(abs(real(O(con_ro,con_co))),1)=co_x(abs(real(O(con_ro,con_co))),1)+1; eta(abs(real(O(con_ro,con_co))),co_x(abs(real(O(con_ro,con_co))),1))=con_ro; coj_mt(con_ro,abs(real(O(con_ro,con_co))))=imag(O(con_ro,con_co)); end end end eta=eta.'; %Sort is not necessary eta=sort(eta); eta=eta.'; for SNR=snr_min:snr_max %Start simulation clc disp('Wait until SNR=');disp(snr_max); SNR n_err_sym=0; n_err_bit=0; graph_inf_sym(SNR-snr_min+1,1)=SNR; graph_inf_bit(SNR-snr_min+1,1)=SNR; for con_sym=1:Nit bi_data=randint(num_X,num_bit_per_sym); %Random binary data de_data=bi2de(bi_data); %Convert binary data to decimal for use in M-PSK mod. data=pskmod(de_data,M_psk,0,'gray'); H=randn(Nt,Nr)+j*randn(Nt,Nr); %Path gains matrix XX=zeros(co_time,Nt); for con_r=1:co_time %Start space time coding for con_c=1:Nt if abs(real(O(con_r,con_c)))~=0 if imag(O(con_r,con_c))==0 XX(con_r,con_c)=data(abs(real(O(con_r,con_c))),1)*sign(real(O(con_r,con_c))); else XX(con_r,con_c)=conj(data(abs(real(O(con_r,con_c))),1))*sign(real(O(con_r,con_c))); end end end end %End space time coding H=H.'; XX=XX.'; snr=10^(SNR/10); Noise=(randn(Nr,co_time)+j*randn(Nr,co_time)); %Generate Noise Y=(sqrt(snr/Nt)*H*XX+Noise).'; %Received signal H=H.'; %Start decoding with perfect channel estimation for co_ii=1:num_X for co_tt=1:size(eta,2) if eta(co_ii,co_tt)~=0 if coj_mt(eta(co_ii,co_tt),co_ii)==0 r_til(eta(co_ii,co_tt),:,co_ii)=Y(eta(co_ii,co_tt),:); a_til(eta(co_ii,co_tt),:,co_ii)=conj(H(epsilon(eta(co_ii,co_tt),co_ii),:)); else r_til(eta(co_ii,co_tt),:,co_ii)=conj(Y(eta(co_ii,co_tt),:)); a_til(eta(co_ii,co_tt),:,co_ii)=H(epsilon(eta(co_ii,co_tt),co_ii),:); end end end end RR=zeros(num_X,1); for ii=1:num_X %Generate decision statistics for the transmitted signal "xi" for tt=1:size(eta,2) for jj=1:Nr if eta(ii,tt)~=0 RR(ii,1)=RR(ii,1)+r_til(eta(ii,tt),jj,ii)*a_til(eta(ii,tt),jj,ii)*delta(eta(ii,tt),ii); end end end end re_met_sym=pskdemod(RR,M_psk,0,'gray'); % = ML decision for M-PSK re_met_bit=de2bi(re_met_sym); re_met_bit(1,num_bit_per_sym+1)=0; %For correct demension of "re_met_bit" for con_dec_ro=1:num_X if re_met_sym(con_dec_ro,1)~=de_data(con_dec_ro,1) n_err_sym=n_err_sym+1; for con_dec_co=1:num_bit_per_sym if re_met_bit(con_dec_ro,con_dec_co)~=bi_data(con_dec_ro,con_dec_co) n_err_bit=n_err_bit+1; end end end end end Perr_sym=n_err_sym/(num_X*Nit); %Count number of error bits and symbols graph_inf_sym(SNR-snr_min+1,2)=Perr_sym; Perr_bit=n_err_bit/(num_X*Nit*num_bit_per_sym); graph_inf_bit(SNR-snr_min+1,2)=Perr_bit; end x_sym=graph_inf_sym(:,1); %Generate plot y_sym=graph_inf_sym(:,2); subplot(2,1,1); semilogy(x_sym,y_sym,'k-v'); xlabel('SNR, [dB]'); ylabel('Symbol Error Probability'); grid on x_bit=graph_inf_bit(:,1); y_bit=graph_inf_bit(:,2); subplot(2,1,2); semilogy(x_bit,y_bit,'k-v'); xlabel('SNR, [dB]'); ylabel('Bit Error Probability'); grid on