main.m

ofdm中互补序列降低par的ber程序

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%      主函数               %%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

b1=zeros(1,20);
b2=zeros(1,20);
b3=zeros(1,20);
for j=13:20
snr=j;                                          %信噪比
len=40000;                                          %编码的总长度，每四个为一组
information=source(len);                           %产生信源并调制
output=encode(information,len);                    %ifft输出
out_wotcode=modulation(information);               %没有经过编码的参考输出

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%         AWGN信道         %%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

ni=randn(1,len*2);
nic=randn(1,len);
nq=randn(1,len*2);
nqc=randn(1,len);	
ngauss=ni+nq*i;
ngaussc=nic+nqc*i;
P=1;				  	                      
snr=10^(snr/10);	 	                       
sgma=sqrt(P/snr);
ngauss=ngauss*sgma;
ngaussc=ngaussc*sgma;
out_wotcode=out_wotcode+ngaussc;                   %加噪声
rec=output/1.414+ngauss;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%      解调和译码        %%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

guzhi=demodulation(rec);
sd=softdec(rec);
outinf_wotcode=demodulation(out_wotcode);          %解调 
outinf=decode(guzhi);                              %解码
[num,ber]=symerr(information,outinf);              %各种方法的误符号率
[numc,berc]=symerr(information,outinf_wotcode);    
[nums,bers]=symerr(information,sd);
b1(j)=bers;
b2(j)=berc;
b3(j)=ber;
end

x=1:20;
semilogy(x,b1,x,b2,x,b3);
%xlable('SNR/dB');
%ylable('SER');
%title('不同信噪比下的误符号率对比');