基于STBC空时分组码的MIMO-OFDM-QPSK通信链路误码率matlab仿真,包含仿真操作录像,代码中文注释

clc; clear; close all; warning off; addpath(genpath(pwd)); rng('default') %fft长度 Len_ifft = 512; %子载波数 N_subcarrier = 100; %符号数/载波 sym_carrier = 66; %循环前缀长度 Len_cp = 10; Len_all = Len_ifft+Len_cp; mods = 4; %位数/符号 bit_sym = log2(mods); Mod_map = [1 -2 -3;2+j 1+j 0;3+j 0 1+j;0 -3+j 2+j]; Len_map = size(Mod_map,1); %发射天线数目 N_Tant = size(Mod_map,2); %接收天线数目 N_Rant = 2; %发射 X_max = 1; for ij1=1:Len_map for ij2=1:N_Tant X_max = max(X_max,abs(real(Mod_map(ij1,ij2)))); end end X0 = zeros(X_max,1); for ij1=1:Len_map for ij2=1:N_Tant if abs(real(Mod_map(ij1,ij2)))~=0 d1(ij1,abs(real(Mod_map(ij1,ij2)))) = sign(real(Mod_map(ij1,ij2))); d2(ij1,abs(real(Mod_map(ij1,ij2)))) = ij2; X0(abs(real(Mod_map(ij1,ij2))),1) = X0(abs(real(Mod_map(ij1,ij2))),1)+1; d3(abs(real(Mod_map(ij1,ij2))),X0(abs(real(Mod_map(ij1,ij2))),1)) = ij1; d4(ij1,abs(real(Mod_map(ij1,ij2)))) = imag(Mod_map(ij1,ij2)); end end end d3 = d3.'; d3 = sort(d3); d3 = d3.'; carriers = (1: N_subcarrier) + (floor(Len_ifft/4) - floor(N_subcarrier/2)); Len_conj = Len_ifft-carriers+2; Pn_symbols = PN_gen(N_Tant,N_subcarrier); Len_bd = N_subcarrier * sym_carrier; SNRs = [0:1:20]; ybits=zeros(length(SNRs),2,N_Rant); ysymb=zeros(length(SNRs),2,N_Rant); for ij=1:length(SNRs) ij Err_sym = zeros(1,N_Rant); Err_bit = zeros(1,N_Rant); Perr_sym = zeros(1,N_Rant); Perr_bit = zeros(1,N_Rant); tmps_sym = zeros(N_subcarrier,sym_carrier,N_Rant); tmps_bit = zeros(Len_bd,bit_sym,N_Rant); %生成随机数用于仿真 msg = round(rand(Len_bd,bit_sym)); %二进制向十进制转换 msg_bit = bi2de(msg); %QPSK msg_qpsk = pskmod(msg_bit,mods,0); msg_matrix = reshape(msg_qpsk,N_subcarrier,sym_carrier); %STBC for ijt=1:N_Tant:sym_carrier data=[]; for ijt4=1:N_Tant tx_tmps = msg_matrix(:,ijt+ijt4-1); data = [data;tx_tmps]; end X1 = zeros(Len_map*N_subcarrier,N_Tant); %STBC for ijt1=1:Len_map for ijt2=1:N_Tant if abs(real(Mod_map(ijt1,ijt2)))~=0 if imag(Mod_map(ijt1,ijt2))==0 X1((ijt1-1)*N_subcarrier+1:ijt1*N_subcarrier,ijt2)=data((abs(real(Mod_map(ijt1,ijt2)))-1)*N_subcarrier+1:abs(real(Mod_map(ijt1,ijt2)))*N_subcarrier,1)*sign(real(Mod_map(ijt1,ijt2))); else X1((ijt1-1)*N_subcarrier+1:ijt1*N_subcarrier,ijt2)=conj(data((abs(real(Mod_map(ijt1,ijt2)))-1)*N_subcarrier+1:abs(real(Mod_map(ijt1,ijt2)))*N_subcarrier,1))*sign(real(Mod_map(ijt1,ijt2))); end end end end %加PN X1 = [Pn_symbols;X1]; Rx_tmps = zeros(1,Len_all*(Len_map+1),N_Rant); for ijt3=1:N_Rant for ijt4=1:N_Tant data_tx = reshape(X1(:,ijt4),N_subcarrier,Len_map+1); data_ifft = zeros(Len_ifft,Len_map+1); data_ifft(carriers,:) = data_tx(1:N_subcarrier,:); data_ifft(Len_conj,:) = conj(data_tx(1:N_subcarrier,:)); data_time = ifft(data_ifft); data_time = [data_time((Len_ifft-Len_cp+1):Len_ifft,:);data_time]; tx = data_time(:)'; %信道模拟 txch = awgn(tx,SNRs(ij),'measured'); Rx_tmps(1,:,ijt3) = Rx_tmps(1,:,ijt3)+txch; end %接收机 Rx_matrix = reshape(Rx_tmps(1,:,ijt3),Len_all,Len_map+1); Rx_matrix = Rx_matrix(Len_cp+1:Len_all,:); data_fft = zeros(Len_ifft,Len_map+1); data_fft = fft(Rx_matrix); data_fft2 = data_fft(carriers,:); data_fft2_tmps = (data_fft2(:,2:Len_map+1)); data_fft2_tmps = conj(data_fft2_tmps'); data_fft2_tmps2= data_fft2(:,1); Wk = exp((-2*pi/N_subcarrier)*sqrt(-1)); L = 10; p = zeros(L*N_Tant,1); for ijt6=1:N_Tant for ijt7=0:L-1 for ijt8=0:N_subcarrier-1 p(ijt7+(ijt6-1)*L+1,1)=p(ijt7+(ijt6-1)*L+1,1)+data_fft2_tmps2(ijt8+1,1)*conj(Pn_symbols(ijt8+1,ijt6))*Wk^(-(ijt8*ijt7)); end end end h=p/N_subcarrier; H_buf=zeros(N_subcarrier,N_Tant); for ijt4=1:N_Tant for ijt8=0:N_subcarrier-1 for ijt7=0:L-1 H_buf(ijt8+1,ijt4)=H_buf(ijt8+1,ijt4)+h(ijt7+(ijt4-1)*L+1,1)*Wk^(ijt8*ijt7); end end end H_buf = conj(H_buf'); RRR=[]; for ijt8=1:N_subcarrier Y=data_fft2_tmps(:,ijt8); H=H_buf(:,ijt8); for ijt9=1:X_max for ijt10=1:size(d3,2) if d3(ijt9,ijt10)~=0 if d4(d3(ijt9,ijt10),ijt9)==0 r_til(d3(ijt9,ijt10),:,ijt9)=Y(d3(ijt9,ijt10),:); a_til(d3(ijt9,ijt10),:,ijt9)=conj(H(d2(d3(ijt9,ijt10),ijt9),:)); else r_til(d3(ijt9,ijt10),:,ijt9)=conj(Y(d3(ijt9,ijt10),:)); a_til(d3(ijt9,ijt10),:,ijt9)=H(d2(d3(ijt9,ijt10),ijt9),:); end end end end RR=zeros(X_max,1); %接收数据的判决统计 for iii=1:X_max for ttt=1:size(d3,2) if d3(iii,ttt)~=0 RR(iii,1)=RR(iii,1)+r_til(d3(iii,ttt),1,iii)*a_til(d3(iii,ttt),1,iii)*d1(d3(iii,ttt),iii); end end end RRR=[RRR;conj(RR')]; end r_sym = pskdemod(RRR,mods,0); tmps_sym(:,ijt:ijt+N_Tant-1,ijt3)= r_sym; end end re_met_sym=zeros(Len_bd,1,N_Rant); for ijt3=1:N_Rant re_met_sym_buf_buf=tmps_sym(:,:,ijt3); re_met_sym(:,1,ijt3)= re_met_sym_buf_buf(:); tmps_bit(:,:,ijt3)=de2bi(re_met_sym(:,1,ijt3)); for con_dec_ro=1:Len_bd if re_met_sym(con_dec_ro,1,ijt3)~=msg_bit(con_dec_ro,1) Err_sym(1,ijt3)=Err_sym(1,ijt3)+1; for con_dec_co=1:bit_sym if tmps_bit(con_dec_ro,con_dec_co,ijt3)~=msg(con_dec_ro,con_dec_co) Err_bit(1,ijt3)=Err_bit(1,ijt3)+1; end end end end %+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ %++++++++++++++++++++++++++误码率计算+++++++++++++++++++++++++++++ Perr_sym(1,ijt3)=Err_sym(1,ijt3)/(Len_bd);