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1、%%dpsk格雷码矩形%%等效基带调制clc;clearall;closeall;%%关闭所有窗口，比如之前画的图nsymbol=1e6;%%每种信噪比下符号数的发送符号数，10^6个数errornumber=zeros(1,10);errorratio=zeros(1,10);dataa=randi([0,1],1,2*nsymbol);%%产生1行，2*nsymbol列均匀分布的随机数datab=zeros(1,2*nsymbol);data_mod1=zeros(1,nsymbol);%%各参量初始化data_mod2=zeros(1,nsymbol);data_demo
2、d1=zeros(1,nsymbol);data_demod2=zeros(1,nsymbol);s_receive1=zeros(1,nsymbol);s_receive2=zeros(1,nsymbol);datab_receive=zeros(1,2*nsymbol);dataa_receive=zeros(1,2*nsymbol);datab(1)=xor(0,dataa(1));%%给定初始相位forl=2:(2*nsymbol)%%逻辑运算datab(l)=xor(dataa(l),datab(l-1));endfori=1:nsymbol%%格雷码调制到星座图的映
3、射ifdatab(2*i-1)==0&&datab(2*i)==0data_mod1(i)=1;data_mod2(i)=1;elseifdatab(2*i-1)==0&&datab(2*i)==1data_mod1(i)=-1;data_mod2(i)=1;elseifdatab(2*i-1)==1&&datab(2*i)==1data_mod1(i)=-1;data_mod2(i)=-1;elseifdatab(2*i-1)==1&&datab(2*i)==0data_mod1(i)=1;data_mod2(i)=-1;endendSNR_dB=1:10;%%%信噪比dB形
4、式SNR=10.^(SNR_dB/10);%%信噪比转化为线性值forloop=1:10sigma=sqrt(1/SNR(loop));%%%根据符号功率求噪声功率s_receive1=data_mod1+sigma*randn(1,length(data_mod1));s_receive2=data_mod2+sigma*randn(1,length(data_mod2));%%添加复高斯白噪声fork=1:nsymbol%%反映射ifs_receive1(k)>0&&s_receive2(k)>0data_demod1(k)=0;data_demod2(k)=0;elsei
5、fs_receive1(k)<0&&s_receive2(k)>0data_demod1(k)=0;data_demod2(k)=1;elseifs_receive1(k)<0&&s_receive2(k)<0data_demod1(k)=1;data_demod2(k)=1;elseifs_receive1(k)>0&&s_receive2(k)<0data_demod1(k)=1;data_demod2(k)=0;enddatab_receive(2*k-1)=data_demod1(k);datab_receive(2*k)=data_demod2(k);enddataa
6、_receive(1)=xor(0,datab_receive(1));forn=2:(2*nsymbol)dataa_receive(n)=xor(datab_receive(n),datab_receive(n-1));endform=1:nsymbolif(dataa_receive(2*m-1)~=dataa(2*m-1))
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8、(dataa_receive(2*m)~=dataa_receive(2*m))%%统计误码个数errornumber(loop)=errornumber(loop)+1;endenderrorratio(loop)=errornumber(lo
9、op)/nsymbol;%%计算误码率endser_theory=1-(1-qfunc(sqrt(SNR))).^2;%理论误码率，注意Q函数和误差函数的对应关系semilogy(SNR_dB,errorratio,'-k*',SNR_dB,ser_theory,'-ro');title('DPSK信号在AWGN信道下的性能（格雷码）');xlabel('信噪比/dB');ylabel('误码率');legend('误码率','理论误码率');gridon;%%坐标线
