msk的调制解调MATLAB源代码.docx

1、msk的调制解调MATLAB源代码msk的调制解调MATLA源代码fun cti on out = delay(data ,n, sample_ nu mber)%data:延迟的数据%n:延迟码元个数%sample_ nu mber码 元采样个数out = zeros(1,le ngth(data);out( n*sample_ nu mbe 叶1:le ngth(data)=data(1:le ngth(data)-n*sample_ nu mber);fun cti on data_diff = differe nce(data)%差分编码%*%data 输入信号%data_d iff

2、差分编码后信号%*data_diff = zeros(1,le ngth(data);data_diff(1) = 1 * data(1); %1为差分编码的初始参考值for i = 2:le ngth(data)data_diff(i) = data_diff(i-1) * data(i);end%*fun cti on sig nal_out,l_out,Q_out= mod_msk(data,data_le n,sample_ nu mber,Rb)%MS基带调制%*% data 调制信号% data_le n 码元个数% sample_ nu mber 每个码元采样点数% Rb码元速率

3、% sig nal_out基带调制输出% I_outI路输出% Q_outQ路输出%*% data_le n 二 10; %码元个数% sample_ nu mber = 8; %采样点数% Rb = 16000; %码元速率% datal = randin t(1,data_le n);% data = 2*data1-1; %传输的序列Tb = 1/Rb; %码元时间fs = Rb*sample_number; %采样速率% %差分编码data_diff = differe nce(data);%*%并串转换，延时1(1) = 1; %faiO = 0,cos(fai0) = 1for i

4、 = 1:2:data_le nQ(i) = data_diff(i);Q(i+1) = data_diff(i);endfor i = 2:2:data_le nI(i+1) = data_diff(i);I(i) = data_diff(i);endfor i = 1:sample_ nu mberI1(i:sample_ nu mber:data_le n*sample_ nu mber)=I(1:dataen);Q1(i:sample_ nu mber:data_le n*sample_ nu mber)=Q(1:data_le n);end%*%乘加权函数t=1/fs:1/fs:da

5、ta_le n*Tb;l_out = I1 .* cos(pi*t/2/Tb);Q_out = Q1 .* si n( pi*t/2/Tb);%*% %调制信号产生sig nal_out = I_out + j*Q_out;%*% % % %|图% subplot(221)时间% plot(data,.-);title(MSK 传输的数据);xlabel(*3nH)y_abe_(w)% subp_of(222)% p-oadafaldiff:-.辽 m 可3選箔)x_abe-( 兰凹)y_abe_(w)% subp_of(223)% p_2-(-1)s_e( MOtf -)x_abe_( 兰凹

6、)y_abe三w)% subp_of(224)% p_of(Q1:-)s_e( MOtf Q)x_abe_( 兰凹)y_abe三w)% figue(2)%subpof(22)% p_2.(cos(pi*t/2Hb)一abe三 鱼凹)y_abe_(w)% subp_of(222)% p_2.(sin(piG2Hb)一abe三 鱼凹)y_abe_( s )% subp_of(223)% p_of(_louu0;demod_data = 2*demod_data-1;%*% % 计算误码率nu m,ber(SNR+1)=symerr(demod_data,data);%*end%*% 頰码率曲线se

7、milogy(0:8,ber,r*-);%*% 頰码率理论值snr = 0:0.1:8;for i = 1:le ngth(s nr)sn r1(1,i) = 10A(s nr(1,i)/10);ps(1,i) = 1/2 * erfc(sqrt(s nr1(1,i);pe(1,i) = 2 * ps(1,i);endhold onsemilogy(0:.1:8,pe);%*%MS调制，差分解调方法二clear allclose all% %参数设置data_le n 二 10000;%码元个数sample_ nu mber = 8;%采样个数Rb = 24000;%码元速率fc = 9600

8、0;%载波频率%*% %随机产生传输信号data二ra nd_bin ary(data_le n);%*% %MS基带调制sig nal_out,l_out,Q_out=mod_msk(data,data_le n,sample_ nu mber,Rb);%*% 帅频搬移multi = fc/Rb;I_temp=in terp(I_out,multi);Q_temp=i nterp(Q_out,multi);Fs二fc*sample_ nu mber;t=1/Fs:1/Fs:le ngth(l_temp)*1/Fs;sig nal=l_temp.*cos(2*pi*fc*t);sig nal_

9、q二Q_temp.*si n(2*pi*fc*t);sig nal_mod=l_temp.*cos(2*pi*fc*t)-Q_temp.*si n(2*pi*fc*t);%*% %加噪声for SNR = 0:8sig nal_mod1 = awg n(sig nal_mod,SNR);% %去载波N=300; %滤波器的阶数为(N+1)F二0,fc-1000,fc+1000,Fs/2*2/Fs;A=1,1,0,0；lpf=firls(N,F,A);amp_lpf,w=freqz(lpf);l_dem二sig nal_mod1.*cos(2*pi*fc*t)*2;I_dem=c on v(l_

10、dem,lpf);l_dem=l_dem(N/2+1:N/2+le ngth(l_temp);Q_dem=sig nal_mod1.*si n(2*pi*fc*t)*2;Q_dem=c on v(Q_dem,lpf);Q_dem=-Q_dem(N/2+1:N/2+le ngth(l_temp);l_dem_out=zeros(1,le ngth(l_dem)/multi); % 抽取Q_dem_out=zeros(1,le ngth(Q_dem)/multi);for i=1:le ngth(l_dem_out)l_dem_out(i)=l_dem(multi*(i-1)+1);Q_dem_o

11、ut(i)=Q_dem(multi*(i-1)+1);end;%*% %差分解调demod_data = zeros(1,data_le n);demod_data(1) = Q_dem_out(sample_ nu mber);for i = 2:2:data_le ndemod_data(i)=-l_dem_out(i*sample_ nu mber)*Q_dem_out(i-1)*sample_ nu mber); endfor i = 3:2:data_le ndemod_data(i)=Q_dem_out(i*sample_ nu mber)*l_dem_out(i-1)*sampl

12、e_ nu mber); end%*% %判决demod_data = demod_data0;demod_data = 2*demod_data-1;%*% % 计算误码率nu m,ber(SNR+1)=symerr(demod_data,data);%*end%*% 頰码率曲线semilogy(0:8,ber,r*);%*% 頰码率理论值snr = 0:0.1:8;for i = 1:le ngth(s nr)sn r1(1,i) = 10A(s nr(1,i)/10);ps(1,i) = 1/2 * erfc(sqrt(s nr1(1,i);pe(1,i) = 2 * ps(1,i);endhold on semilogy(0:.1:8,pe);0/严*%MS制，解调clear allclose all% %参数设置data_len = 30000; %码元个数sample_ nu mber = 8; %采样个数Rb = 24000; %码元速率fc = 96000; %载波频率%*% %随机产生传输信号data = rand_bin ary(data_le n);%*% %MS基带调制sig nal_out,l_out,Q_out=mod_msk(data,data_le n,sample_ nu mber,Rb);%*