dgbqreading-BER.rar_干扰误码率_扩频与解扩_误码率干扰_通讯/手机编程

% 2采样理想情况，无干扰，即信号＋白噪声,普通DSSS系统 %与经过镜像滤波器处理相比较 %这个程序建立了信号从扩频、加干扰信号到解扩、求误码率的仿真模型系统。 echo off clear tic Lc=64; N=1000; %数据长度 po=1; M=2; %一个chip中的采样点数 fd=1; %数据速率 f_pn=Lc*fd; % chip 速率 fs=M*f_pn; % 采样频率 Ts=1/fs; %抽样间隔 %SJR_in_dB=10; snr_in_dB=-4:2:8; level=3; T=2.^level; for m=1:length(snr_in_dB); Num_err1=0; Num_err2=0; snr=10^(snr_in_dB(m)/10); sgma=1; %噪声的标准方差设置为固定值 Eb=2*sgma^2*snr; %达到设定信噪比所需的信号幅度平方 E_chip=Eb/(Lc*M); %每码片的能量 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%产生M序列64 pn1=M_pn1([1 1 0 0 1 1]); pn=2*pn1-1; for i=1:Lc pn_seq((i-1)*M+1:i*M)=pn(i)*ones(1,M); end; %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %产生数据流 for qq=1:N temp1=rand(1,po); for i=1:po if (temp1(i)<0.5), data(i)=-1; else data(i)=1; end; end; trans_sig=sqrt(E_chip)*kron(data,pn_seq); %已扩信号 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%经过重构滤波器处理 sig=[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ]; temp=rand; %%选择走哪组滤波器组 %%选择第一组滤波器组，低通-低通-低通，解扩时，走对称滤波器组低通-低通-低通 if (temp<1/T) %temp< 0.125 channel=1; sig(channel)=data; sig_spread=spread_num(sig,channel); end; %%选择第二组滤波器组，高通-低通-低通，解扩时，走对称滤波器组：高通-低通-低通 if((temp>1/T)&(temp<2/T)) % 0.125<temp<0.25 channel=2; sig(channel)=data; sig_spread=spread_num(sig,channel); end; %%选择第三组滤波器组，低通-高通-低通，解扩时，走对称滤波器组：低通-高通-低通 if((temp>2/T)&(temp<3/T)) % 0.25<temp<0.375 channel=3; sig(channel)=data; sig_spread=spread_num(sig,channel); end; %%第四组:高通-高通-低通,解扩时:低通-高通-高通 if((temp>3/T)&(temp<4/T)) %0.375<temp<0.5 channel=4; sig(channel)=data; sig_spread=spread_num(sig,channel); end; %%第五组:低通-低通-高通,解扩时:高通-低通-低通 if((temp>4/T)&(temp<5/T)) %0.5<temp<0.625 channel=5; sig(channel)=data; sig_spread=spread_num(sig,channel); end; %%第六组:高通-低通-高通,解扩时:高通-低通-高通 if((temp>5/T)&(temp<6/T)) %0.625<temp<0.75 channel=6; sig(channel)=data; sig_spread=spread_num(sig,channel); end; %%第七组:低通-高通-高通,解扩时:高通-高通-低通 if((temp>6/T)&(temp<7/T)) %0.75<temp<0.875 channel=7; sig(channel)=data; sig_spread=spread_num(sig,channel); end; %%第八组:高通-高通-高通,解扩时:高通-高通-高通 if((temp>7/T)&(temp<8/T)) %0.875<temp<1 channel=8; sig(channel)=data; sig_spread=spread_num(sig,channel); end; %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %产生高斯白噪声 noise=randn(1,Lc*fd*M); white_noise=sgma*noise; %产生干扰 A=20; interference=A*[zeros(1,100),1,zeros(1,Lc*M-101)]; %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %产生接收信号 sig_rec1=trans_sig+white_noise+interference; sig_rec2= sqrt(Eb)*sig_spread'+white_noise+interference; %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %接受信号经过分解滤波器还原 if ( channel==1) DEF=[0 0 0]; end_sig=de_num(DEF,sig_rec2'); end; if ( channel==2) DEF=[0 0 1]; end_sig=de_num(DEF,sig_rec2'); end; if ( channel==3) DEF=[0 1 0]; end_sig=de_num(DEF,sig_rec2'); end; if ( channel==4) DEF=[0 1 1]; end_sig=de_num(DEF,sig_rec2'); end; if ( channel==5) DEF=[1 0 0]; end_sig=de_num(DEF,sig_rec2'); end; if ( channel==6) DEF=[1 0 1]; end_sig=de_num(DEF,sig_rec2'); end; if ( channel==7) DEF=[1 1 0]; end_sig=de_num(DEF,sig_rec2'); end; if ( channel==8) DEF=[1 1 1]; end_sig=de_num(DEF,sig_rec2'); end; sig_rec3=end_sig'; %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% for i=1:po; sig_des1=sig_rec1((i-1)*Lc*M+1:i*Lc*M).*pn_seq; %判决 temp11=sum(sig_des1); if temp11>=0; de_data(i)=1; else de_data(i)=-1; end; if de_data(i)~=data(i); Num_err1=Num_err1+1; end; temp12= sig_rec3(channel); if temp12>=0; de_data(i)=1; else de_data(i)=-1; end; if de_data(i)~=data(i); Num_err2=Num_err2+1; end; end; end; p1(m)=Num_err1/N; p2(m)=Num_err2/N; end; semilogy(snr_in_dB,p1,'-r*',snr_in_dB,p2,'-b*');grid; axis([-4,8,0.00001,1]); legend('DSSS','经过小波镜像滤波器处理'); title('2采样,DSSSVs.经过小波镜像滤波器处理的误码率'); xlabel('Eb/N0'); ylabel('误码率Pe'); toc