一个完整的3G码分多址matlab仿真~采用的是正弦波叠加法模拟瑞利衰落

clc data_length=1000; snr1=-20; Pem_group=zeros(1,21); Pegold_group=zeros(1,21); for b=1:21 expand_length=127; %data=zeros(1,data_length); data=suiji(data_length); %plot(data); [m4,c2]=msq(); transmitdata_m=dm(data,m4); plot(transmitdata_m); transmit_m=mods(transmitdata_m); check=mods(data); %plot(transmit_m); %plot(check); transmitdata_gold=dm(data,c2); transmit_gold=mods(transmitdata_gold); %plot(transmit_gold); transcheck=awgn_etu300(check,check,0); %plot(transcheck); transmit_channel=awgn_sum(transmit_m,transmit_gold,snr1); %plot(transmit_channel); receive_mod=zeros(1,length(transmit_channel)); for s=1:length(transmit_channel) receive_mod(s)=transmit_channel(s).*cos(0.001*pi*s); end %plot(receive_mod); %receive_m=dm(receive_mod,m4); %plot(receive_mod); g=length(receive_mod); receivedata_sum=zeros(1,data_length*expand_length); receivedata=zeros(1,data_length); %按每个比特进行检查 resultdatam=zeros(1,data_length+1); resultdatagold=zeros(1,data_length+1); for u=1:g/2000 if((receive_mod(u*2000-1000)>-0.5)&&(receive_mod(u*2000-1000)<0.5)) receivedata_sum(u)=0; end if((receive_mod(u*2000-1000)<-0.5)&&(receive_mod(u*2000-1000)>-1.5)) receivedata_sum(u)=-1; end if((receive_mod(u*2000-1000)>0.5)&&(receive_mod(u*2000-1000)<1.5)) receivedata_sum(u)=1; end if(receive_mod(u*2000-1000)>1.5) receivedata_sum(u)=2; end if(receive_mod(u*2000-1000)<-1.5) receivedata_sum(u)=-2; end end plot(receivedata_sum); %total_length=g/2000; counter=1; adder=0; for k=1:length(receivedata_sum) adder=adder+receivedata_sum(k).*c2(counter); counter=counter+1; if(counter==expand_length+1) counter=1; j=floor(k/127)+1; resultdatagold(j)=adder/expand_length; adder=0; end end for k=1:length(receivedata_sum) adder=adder+receivedata_sum(k).*m4(counter); counter=counter+1; if(counter==expand_length+1) counter=1; j=floor(k/127)+1; resultdatam(j)=adder/expand_length; adder=0; end end plot(resultdatam); for k=2:data_length+1 resultdatam(k-1)=resultdatam(k); resultdatagold(k-1)=resultdatagold(k); end for t=1:data_length d=resultdatam(t); v=resultdatagold(t); if(d>0.5) resultdatam(t)=1; end if(d<-0.5) resultdatam(t)=-1; end if(v>0.5) resultdatagold(t)=1; end if(v<-0.5) resultdatagold(t)=-1; end end errorm=0; errorgold=0; for e=1:data_length if(resultdatam(e)~=data(e)) errorm=errorm+1; end if(resultdatagold(e)~=data(e)) errorgold=errorgold+1; end end Pem_group(b)=errorm/data_length; Pegold_group(b)=errorgold/data_length; snr1=snr1+1; end subplot(1,2,1); plot(Pem_group); subplot(1,2,2); plot(Pegold_group);