任意发送天线,任意接收天线的STBC

%STBC-MIMO-OFDM.m clear all; i=sqrt(-1); IFFT_bin_length=512; % 傅立叶变换 抽样点数目 carrier_count=100; %子载波数目 symbols_per_carrier=66; %符号数 /载 波 cp_length=10; %循环前缀长度 addprefix_length=IFFT_bin_length+cp_length; M_psk=4; bits_per_symbol=log2(M_psk); %位数 /符号 %O=1 2;-2+j 1+j; %Alamouti Scheme x1 x2;-x2* x1* 二天线发送矩阵 O=1 -2 -3;2+j 1+j 0;3+j 0 1+j;0 -3+j 2+j; %for x1 -x2 -x3;x2* x1* 0;x3* 0 x1*;0 -x3* x2*三天线发送矩阵co_time=size(O,1); Nt=size(O,2); %发射天线数目 Nr=2; %接收天线数目 num_X=1; 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 %计算 delta,epsilon,eta and conj matrices for con_co=1:Nt %用于确定矩阵 “ O”中元素的位置，符号以及共轭情况 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.; eta=sort(eta); eta=eta.; carriers = (1: carrier_count) + (floor(IFFT_bin_length/4) - floor(carrier_count/2); % 坐标： (1 to 100) + 14=(15:114) conjugate_carriers=IFFT_bin_length-carriers+2; %坐 标 ：256 - (15:114) + 1= 257 - (15:114) = (242:143) tx_training_symbols=training_symbol(Nt,carrier_count); baseband_out_length = carrier_count * symbols_per_carrier; snr_min=3; %最小信噪比 snr_max=15; %最大信噪比 graph_inf_bit=zeros(snr_max-snr_min+1,2,Nr); %绘图信息存储矩阵 graph_inf_sym=zeros(snr_max-snr_min+1,2,Nr); for SNR=snr_min:snr_max %开始仿真 clc disp(Wait until SNR=);disp(snr_max); SNR n_err_sym=zeros(1,Nr); n_err_bit=zeros(1,Nr); Perr_sym=zeros(1,Nr); Perr_bit=zeros(1,Nr); re_met_sym_buf=zeros(carrier_count,symbols_per_carrier,Nr); re_met_bit=zeros(baseband_out_length,bits_per_symbol,Nr); baseband_out=round(rand(baseband_out_length,bits_per_symbol); 生%成随机数用于 仿真 de_data=bi2de(baseband_out); %二进制向十进制转换 data_buf=pskmod(de_data,M_psk,0); %PSK调制 carrier_matrix=reshape(data_buf,carrier_count,symbols_per_carrier); for tt=1:Nt:symbols_per_carrier %取数为空时编码做准备，此处每次取每个子载波上 连续的两个数 data=; for ii=1:Nt tx_buf_buf=carrier_matrix(:,tt+ii-1); data=data;tx_buf_buf; end XX=zeros(co_time*carrier_count,Nt); for con_r=1:co_time %进行空时编码 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- 1)*carrier_count+1:con_r*carrier_count,con_c)=data(abs(real(O(con_r,con_c)- 1)*carrier_count+1:abs(real(O(con_r,con_c).*carrier_count,1)*sign(real(O(con_r,con_c); else XX(con_r- 1)*carrier_count+1:con_r*carrier_count,con_c)=conj(data(abs(real(O(con_r,con_c)- 1)*carrier_count+1:abs(real(O(con_r,con_c).*carrier_count,1)*sign(real(O(con_r,con_c); end end end end %空时编码结束 XX=tx_training_symbols;XX; % 添加训练序列 rx_buf=zeros(1,addprefix_length*(co_time+1),Nr); for rev=1:Nr for ii=1:Nt tx_buf=reshape(XX(:,ii),carrier_count,co_time+1);IFFT_tx_buf=zeros(IFFT_bin_length,co_time+1); IFFT_tx_buf(carriers,:)=tx_buf(1:carrier_count,:);IFFT_tx_buf(conjugate_carriers,:)=conj(tx_buf(1:carrier_count,:); time_matrix=ifft(IFFT_tx_buf); time_matrix=time_matrix(IFFT_bin_length- cp_length+1):IFFT_bin_length,:);time_matrix; tx=time_matrix(:); % %d=randint(1,4,1,7);%4 多经信道模拟 %a=randint(1,4,2,7)/10; tx_tmp=tx; d=4,5,6,2;4,5,6,2;4,5,6,2;4,5,6,2; a=0.2,0.3,0.4,0.5;0.2,0.3,0.4,0.5;0.2,0.3,0.4,0.5;0.2,0.3,0.4,0.5; for jj=1:size(d,2) copy=zeros(size(tx) ; for kk = 1 + d(ii,jj): length(tx) copy(kk) = a(ii,jj)*tx(kk - d(ii,jj) ; end tx_tmp=tx_tmp+copy; end % txch=awgn(tx_tmp,SNR,measured); %添加高斯白噪声 rx_buf(1,:,rev)=rx_buf(1,:,rev)+txch; end rx_spectrum=reshape(rx_buf(1,:,rev),addprefix_length,co_time+1); rx_spectrum=rx_spectrum(cp_length+1:addprefix_length,:);FFT_tx_buf=zeros(IFFT_bin_length,co_time+1); FFT_tx_buf=fft(rx_spectrum); spectrum_matrix=FFT_tx_buf(carriers,:); Y_buf=(spectrum_matrix(:,2:co_time+1);Y_buf=conj(Y_buf); spectrum_matrix1=spectrum_matrix(:,1); Wk=exp(- 2*pi/carrier_count)*i); L=10; p=zeros(L*Nt,1); for jj=1:Nt for l=0:L-1 for kk=0:carrier_count-1 p(l+(jj-1)*L+1,1)=p(l+(jj- 1)*L+1,1)+spectrum_matrix1(kk+1,1)*conj(tx_training_symbols(kk+1,jj)*Wk(- (kk*l); end end end %q=zeros(L*Nt,L*Nt); %for ii=1:Nt % for jj=1:Nt % for l1=0:L- 1 % for l2=0:L-1 % for kk=0:carrier_count-1 % q(l2+(ii-1)*L+1,l1+(jj-1)*L+1)= q(l2+(ii-1)*L+1,l1+(jj- 1)*L+1)+tx_training_symbols(kk+1,ii)*conj(tx_training_symbols(kk+1,jj)*Wk(- (kk*(-l1+l2); % end % end % end % end %end %h=inv(q)*p; h=p/carrier_count;H_buf=zeros(carrier_count,Nt); for ii=1:Nt for kk=0:carrier_count-1 for l=0:L-1 H_buf(kk+1,ii)=H_buf(kk+1,ii)+h(l+(ii-1)*L+1,1)*Wk(kk*l); end end end H_buf=conj(H_buf); RRR=; for kk=1:carrier_count Y=Y_buf(:,kk); H=H_buf(:,kk); 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 iii=1:num_X %Generate decision statistics for the transmitted signal xi for ttt=1:size(eta,2) if eta(iii,ttt)=0 RR(iii,1)=RR(iii,1)+r_til(eta(iii,ttt),1,iii)*a_til(eta(iii,ttt),1,iii)*delta(eta(iii,ttt),iii); end end end RRR=RRR;conj(RR); end r_sym=pskdemod(RRR,M_psk,0); re_met_sym_buf(:,tt:tt+Nt-1,rev)=r_sym; end end re_met_sym=zeros(baseband_out_length,1,Nr); for rev=1:Nr re_met_sym_buf_buf=re_met_sym_buf(:,:,rev); re_met_sym(:,1,rev)= re_met_sym_buf_buf(:); re_met_bit(:,:,rev)=de2bi(re_met_sym(:,1,rev); for con_dec_ro=1:baseband_out_length if re_met_sym(con_dec_ro,1,rev)=de_data(con_dec_ro,1) n_err_sym(1,rev)=n_err_sym(1,rev)+1; for con_dec_co=1:bits_per_symbol if re_met_bit(con_dec_ro,con_dec_co,rev)=baseband_out(con_dec_ro,con_dec_co) n_err_bit(1,rev)=n_err_bit(1,rev)+1; end end end end graph_inf_sym(SNR- snr_min+1,1,rev)=SNR; graph_inf_bit(SNR-snr_min+1,1,rev)=SNR; Perr_sym(1,rev)=n_err_sym(1,rev)/(baseband_out_length); %Count number of error bits and symbols graph_inf_sym(SNR-snr_min+1,2,rev)=Perr_sym(1,rev); Perr_bit(1,rev)=n_err_bit(1,rev)/(baseband_out_length*bits_per_symbol); graph_inf_bit(SNR-snr_min+1,2,rev)=Perr_bit(1,rev); end end for rev=1:rev x_sym=graph_inf_sym(:,1,rev); %Generate plot y_sym=graph_inf_sym(:,2,rev); subplot(Nr,1,rev); semilogy(x_sym,y_sym,k-v); axis(2 16 0.0001 1); xlabel(SNR, dB); ylabel(Symbol Error Probability); grid on %hold on end %hold off %for rev=1:rev %x_bit=graph_inf_bit(:,1,rev); %y_bit=graph_inf_bit(:,2,rev); %subplot(2,1, 2); %semilogy(x_bit,y_bit,k-v); %axis(2 16 0.0001 1); %xlabel(SNR, dB); %ylabel(Bit Error Probability); %grid on %hold on %end %hold off %training_symbol.M function tx_training_symbols=training_symbol(Nt,carrier_count) j=sqrt(-1); Wk=exp(- 2*pi/carrier_count)*i); training_symbols= 1 j j 1 -1 -j -j -1 1 j j 1 -1 -j -j -1 1 j j 1 -1 -j -j -1 1 j j 1 -1 -j -j -1 1 j j 1 -1 . -j -j -1 1 j j 1 -1 -j -j -1 1 j j 1 -1 -j -j -1 1 j j 1 -1 -j -j -11 j j 1 -1 -j -j -1 1 . j j 1 -1 -j -j -1 1 j j 1 -1 -j -j -1 1 j j 1 -1 -j -j -1 1 j j 1 ; tx_training_symbols=; for ii=1:carrier_count training_symbols_buf=; for jj=1:Nt training_symbols_buf=training_symbols_buf,Wk(-floor(carrier_count/Nt)*(jj-1)*ii) *training_symbols(ii,1); end tx_training_symbols=tx_training_symbols;training_symbols_buf; end