正交频分复用传输LDPC仿真（含误码率）Matlab实现.zip

close all; clear; clc; % echo on M=input('Please input modulation order M:_(like 4 or 16), or press Enter directly to exit\n'); if(isempty(M)==1) disp('You have exited'); return; end SNRindB=input('Please input SNR(dB) range:_(like 0:1:2), or press Enter directly to exit\n'); if(isempty(SNRindB)==1) disp('You have exited'); return; end frame=input('Please input frame number:_(like 1e1), or press Enter directly to exit\n'); if(isempty(frame)==1) disp('You have exited'); return; end iteration=input('Please input max number of iterations:_(like 10), or press Enter directly to exit\n'); if(isempty(iteration)==1) disp('You have exited'); return; end N=288; R=1/2; Eav=1; num_of_subcarriers_used=144; segment=(N/R)/(num_of_subcarriers_used*log2(M)); num_of_subcarriers=256; L=32; AWGN_numofbiterror=zeros(1,length(SNRindB)); AWGN_numofframeerror=zeros(1,length(SNRindB)); AWGN_iteration_in_SNR=zeros(length(SNRindB),iteration);%统计译码迭代次数 Rayleigh_numofbiterror=zeros(1,length(SNRindB)); Rayleigh_numofframeerror=zeros(1,length(SNRindB)); Rayleigh_iteration_in_SNR=zeros(length(SNRindB),iteration); MFB_numofbiterror=zeros(1,length(SNRindB)); MFB_numofframeerror=zeros(1,length(SNRindB)); MFB_iteration_in_SNR=zeros(length(SNRindB),iteration);%统计译码迭代次数 for f=1:frame % AWGN_frameerror=zeros(1,length(SNRindB)); % Rayleigh_frameerror=zeros(1,length(SNRindB)); % MFB_frameerror=zeros(1,length(SNRindB)); bit0=randi([0 1],N,1); AWGN_decision=zeros(N,1); Rayleigh_decision=zeros(N,1); MFB_decision=zeros(N,1); %编码 bit=LDPC_Encode_half(bit0); % new_bit=LDPC_Encode_two_thirds(bit); %调制 new_bit=reshape(bit,segment*log2(M),num_of_subcarriers_used);%串并转换 %reshape 函数是逐列开始转换，即按矩阵的每一列开始读取，并按列转换为新矩阵 S=qammod(new_bit,M,'InputType','bit','UnitAveragePower',true); new_S=zeros(num_of_subcarriers,segment); new_S([2:num_of_subcarriers_used/2+1,... num_of_subcarriers-num_of_subcarriers_used/2+1:num_of_subcarriers],:)=S.'; s=sqrt(num_of_subcarriers).*ifft(new_S,num_of_subcarriers);%IDFT x=[s(num_of_subcarriers-L+1:num_of_subcarriers,:);s];%加循环前缀 x=reshape(x,1,(num_of_subcarriers+L)*segment);%并串转换 %Rayleigh信道 hq=sqrt(1/(2*L)).*randn(L,1); hr=sqrt(1/(2*L)).*randn(L,1); h=complex(hq,hr);%h SUM=h'*h; newh=zeros(num_of_subcarriers,1); newh(1:L,1)=h; H=fft(newh);%信道在各载波的频响 H_used=H([2:num_of_subcarriers_used/2+1,... num_of_subcarriers-num_of_subcarriers_used/2+1:num_of_subcarriers],1); modul_H=abs(H_used); for l=1:length(SNRindB) noise_power=Eav*10^(-SNRindB(l)/10); %接收信号及解调软信息 %AWGN AWGN_y=awgn(x,SNRindB(l)); AWGN_y=reshape(AWGN_y,num_of_subcarriers+L,segment);%串并转换 AWGN_r=AWGN_y(L+1:L+num_of_subcarriers,:);%去除循环前缀 AWGN_R=sqrt(1/num_of_subcarriers).*fft(AWGN_r,num_of_subcarriers); awgn_R=AWGN_R([2:num_of_subcarriers_used/2+1,... num_of_subcarriers-num_of_subcarriers_used/2+1:num_of_subcarriers],:); LLR_AWGN=qamdemod(awgn_R.',M,'OutputType','approxllr',... 'UnitAveragePower',true,'NoiseVariance', noise_power); LLR_AWGN=reshape(LLR_AWGN,1,N/R); %MFB MFB_y=awgn(sqrt(SUM).*x,SNRindB(l)); MFB_y=reshape(MFB_y,num_of_subcarriers+L,segment);%串并转换 MFB_r=MFB_y(L+1:L+num_of_subcarriers,:);%去除循环前缀 new_MFB_r=MFB_r./sqrt(SUM);%均衡 MFB_R=sqrt(1/num_of_subcarriers).*fft(new_MFB_r,num_of_subcarriers); mfb_R=MFB_R([2:num_of_subcarriers_used/2+1,... num_of_subcarriers-num_of_subcarriers_used/2+1:num_of_subcarriers],:); LLR_MFB=qamdemod(mfb_R.',M,'OutputType','approxllr',... 'UnitAveragePower',true,'NoiseVariance', noise_power/SUM); LLR_MFB=reshape(LLR_MFB,1,N/R); %Rayleigh R_y=conv(x,h); Rayleigh_y=awgn(R_y(1,1:(num_of_subcarriers+L)*segment),SNRindB(l)); Rayleigh_y=reshape(Rayleigh_y,num_of_subcarriers+L,segment);%串并转换 Rayleigh_r=Rayleigh_y(L+1:L+num_of_subcarriers,:);%去除循环前缀 Rayleigh_R=sqrt(1/num_of_subcarriers).*fft(Rayleigh_r,num_of_subcarriers); rayleigh_R=Rayleigh_R([2:num_of_subcarriers_used/2+1,... num_of_subcarriers-num_of_subcarriers_used/2+1:num_of_subcarriers],:); new_rayleigh_R=diag(1./H_used,0)*rayleigh_R;%均衡 LLR_Rayleigh=qamdemod(new_rayleigh_R.',M,'OutputType','approxllr',... 'UnitAveragePower',true,'NoiseVariance', noise_power*modul_H.^-2); LLR_Rayleigh=reshape(LLR_Rayleigh,1,N/R); %译码 %AWGN [AWGN_decision,AWGN_num_of_iteration]=LDPC_Decode_half(LLR_AWGN,iteration); AWGN_iteration_in_SNR(l,AWGN_num_of_iteration)=... AWGN_iteration_in_SNR(l,AWGN_num_of_iteration)+1;%迭代次数对应位置加1 %MFB [MFB_decision,MFB_num_of_iteration]=LDPC_Decode_half(LLR_MFB,iteration); MFB_iteration_in_SNR(l,MFB_num_of_iteration)=... MFB_iteration_in_SNR(l,MFB_num_of_iteration)+1;%迭代次数对应位置加1 %Rayleigh [Rayleigh_decision,Rayleigh_num_of_iteration]=... LDPC_Decode_half(LLR_Rayleigh,iteration); Rayleigh_iteration_in_SNR(l,Rayleigh_num_of_iteration)=... Rayleigh_iteration_in_SNR(l,Rayleigh_num_of_iteration)+1; %统计 %AWGN % for i=1:num % if(AWGN_decision(i)~=bit0(i)) % AWGN_numofbiterror(l)=AWGN_numofbiterror(l)+1; % AWGN_frameerror(l)=1; % end % end AWGN_error=sum(xor(AWGN_decision,bit0)); AWGN_numofbiterror(l)=AWGN_numofbiterror(l)+AWGN_error; if (AWGN_error~=0) AWGN_numofframeerror(l)=AWGN_numofframeerror(l)+1; end %MFB % for i=1:num % if(MFB_decision(i)~=bit0(i)) % MFB_numofbiterror(l)=MFB_numofbiterror(l)+1; % MFB_frameerror(l)=1; % end % end MFB_error=sum(xor(MFB_decision,bit0)); MFB_numofbiterror(l)=MFB_numofbiterror(l)+MFB_error; if (MFB_error~=0) MFB_numofframeerror(l)=MFB_numofframeerror(l)+1; end %Rayleigh % for i=1:N % if(Rayleigh_decision(i)~=bit0(i)) % Rayleigh_numofbiterror(l)=Rayleigh_numofbiterror(l)+1; % Rayleigh_frameerror(l)=1; % end % end Rayleigh_error=sum(xor(Rayleigh_decision,bit0)); Rayleigh_numofbiterror(l)=Rayleigh_numofbiterror(l)+Rayleigh_error; if (+Rayleigh_error~=0) Rayleigh_numofframeerror(l)=Rayleigh_numofframeerror(l)+1; end end % echo off; end AWGN_pf=AWGN_numofframeerror/frame; AWGN_pb=AWGN_numofbiterror/(frame*N); Rayleigh_pf=Rayleigh_numofframeerror/frame; Rayleigh_pb=Rayleigh_numofbiterror/(frame*N); MFB_pf=MFB_numofframeerror/frame; MFB_pb=MFB_numofbiterror/(frame*N); figure(1); %bxy=spcrv([SNRindB;smld_bit_err_prb],3); semilogy(SNRindB,AWGN_pb,'r*-'); hold on semilogy(SNRindB,Rayleigh_pb,'ks--'); hold on semilogy(SNRindB,MFB_pb,'bp-.'); grid on legend('AWGN','Rayleigh慢衰落','Rayleigh慢衰落下的MFB','location','southwest'); %title('OFDM系统误比特率') xlabel('SNR/dB') ylabel('BER') figure(2); %fxy=spcrv([SNRindB;smld_frame_err_prb],3); semilogy(SNRindB,AWGN_pf,'r*-'); hold on semilogy(SNRindB,Rayleigh_pf,'ks--'); hold on semilogy(SNRindB,MFB_pf,'bp-.'); grid on legend('AWGN','Rayleigh慢衰落','Rayleigh慢衰落下的MFB','location','southwest'); %title('OFDM系统误帧率') xlabel('SNR/dB') ylabel('FER')