matlab-(含教程)OFDM+STBC通信系统的误码率matlab仿真

clc; clear all; close all; warning off; addpath 'func\' %OFDM长度 Nfft = 512; %子载波数目 NCarrier = 100; %符号数/载波 Nsymbols = 660; %循环前缀长度 Ncp = 10; Nadder = Nfft+Ncp; Modes = 4; %位数/符号 Nbits = log2(Modes); %发送天线矩阵 Tr_matrix =[1 2;-2+j 1+j]; NTr_matrix= size(Tr_matrix,1); Nt = size(Tr_matrix',2); %发射天线数目 Nr = 2; %接收天线数目 %发射 [Nxx,data_eta,data_delta,data_eps,data_cojm] = func_trans_x(Nt,Tr_matrix,NTr_matrix); %子载波 Carriers = (1: NCarrier) + (floor(Nfft/4) - floor(NCarrier/2)); Len_carriers = Nfft-Carriers+2; Tx_training = func_training_symbol(Nt,NCarrier); Nbase = NCarrier * Nsymbols; SNRs = [0:2:20]; %绘图信息存储矩阵 Bers=zeros(length(SNRs)); idx = 0; for j_snr = SNRs j_snr idx = idx + 1; Nerror = zeros(1,Nr); data_buffer1 = zeros(NCarrier,Nsymbols,Nr); data_bits = zeros(Nbase,Nbits,Nr); %生成随机数用于仿真 Tsignal = round(rand(Nbase,Nbits)); Tsignal2 = bi2de(Tsignal); %PSK调制 Tsignal_mod = pskmod(Tsignal2,Modes,0); Tcar_mat = reshape(Tsignal_mod,NCarrier,Nsymbols); for st1=1:Nt:Nsymbols data = []; for st2=1:Nt data=[data;Tcar_mat(:,st1+st2-1)]; end %STBC data_stbc = func_stbc(data,Tr_matrix,NTr_matrix,NCarrier,Nt); %添加训练序列 data_stbc = [Tx_training;data_stbc]; data_rec = zeros(1,Nadder*(NTr_matrix+1),Nr); for st11=1:Nr for st2=1:Nt data_tra = reshape(data_stbc(:,st2),NCarrier,NTr_matrix+1); data_tra_ifft = zeros(Nfft,NTr_matrix+1); data_tra_ifft(Carriers,:) = data_tra(1:NCarrier,:); data_tra_ifft(Len_carriers,:) = conj(data_tra(1:NCarrier,:)); %IFFT time_matrix = ifft(data_tra_ifft); time_matrix =[time_matrix((Nfft-Ncp+1):Nfft,:);time_matrix]; tx = time_matrix(:)'; %信道 txn = func_channel(tx,st2,j_snr); data_rec(1,:,st11) = data_rec(1,:,st11)+txn; end %接收机 Rx_spec = reshape(data_rec(1,:,st11),Nadder,NTr_matrix+1); [p,L,Wk,Y_buf] = func_rec_fft(Rx_spec,Ncp,Nt,Nadder,Nfft,NTr_matrix,Carriers,NCarrier,Tx_training); h = p/NCarrier; H_buf = func_H(h,NCarrier,Nt,L,Wk); %获得接收数据 data_recf = func_rec_data(data_eta,data_cojm,data_eps,data_delta,Nxx,Y_buf,H_buf,NCarrier); %解调 r_sym = pskdemod(data_recf,Modes,0); data_buffer1(:,st1:st1+Nt-1,st11) = r_sym; end end data_bufferf = zeros(Nbase,Nr); for st11=1:Nr tmps1 = data_buffer1(:,:,st11); data_bufferf(:,st11) = tmps1(:); data_bits(:,:,st11) = de2bi(data_bufferf(:,st11)); for st22=1:Nbase for st33=1:Nbits if data_bits(st22,st33,st11)~=Tsignal(st22,st33) Nerror(st11) = Nerror(st11) + 1; end end end end Bers(idx)=mean(Nerror/(Nbase)); end figure; semilogy(SNRs,Bers,'b-s'); xlabel('信噪比/dB'); ylabel('误码率'); grid on