msk的调制解调MATLAB源代码

1、msk的调制解调MATLAB源代码 function out = delay(data,n,sample_number) %data:延迟的数据 %n:延迟码元个数 %sample_number:码元采样个数 out = zeros(1,length(data); out(n*sample_number+1:length(data) = data(1:length(data)-n*sample_number);function data_diff = difference(data) %差分编码 %* %data       

2、;    输入信号 %data_diff      差分编码后信号 %*  %- data_diff = zeros(1,length(data); data_diff(1) = 1 * data(1);   %1为差分编码的初始参考值 for i = 2:length(data)     data_diff(i) = data_diff(i-1) * data(i); end %*function signal_out,I_out,Q_out = mod

3、_msk(data,data_len,sample_number,Rb) %MSK基带调制 %* % data              调制信号 % data_len          码元个数 % sample_number     每个码元采样点数 % Rb      &#

4、160;         码元速率 % signal_out        基带调制输出 % I_out             I路输出 % Q_out             Q路输出 %*  %

5、 data_len = 10;                %码元个数 % sample_number = 8;            %采样点数 % Rb = 16000;             

6、0;     %码元速率 % data1 = randint(1,data_len); % data = 2*data1-1;             %传输的序列  Tb = 1/Rb;                    &

7、#160; %码元时间 fs = Rb*sample_number;          %采样速率  %- %差分编码 data_diff = difference(data); %*  %- %并串转换，延时 I(1) = 1;             %fai0 = 0,cos(fai0) = 1 for i = 1:2:data_len   

8、  Q(i) = data_diff(i);     Q(i+1) = data_diff(i); end for i = 2:2:data_len     I(i+1) = data_diff(i);     I(i) = data_diff(i); end  for i = 1:sample_number     I1(i:sample_number:data_len*sample_number) = I(1:data_len);  

9、0;  Q1(i:sample_number:data_len*sample_number) = Q(1:data_len); end %*  %- %乘加权函数 t=1/fs:1/fs:data_len*Tb; I_out = I1 .* cos(pi*t/2/Tb); Q_out = Q1 .* sin(pi*t/2/Tb); %*  %- %调制信号产生 signal_out = I_out + j*Q_out; %*  % %- % %画图 % subplot(221) % plot(data,'.-');title('M

10、SK传输的数据');xlabel('时间');ylabel('幅度') % subplot(222) % plot(data_diff,'.-');title('差分后的数据');xlabel('时间');ylabel('幅度') % subplot(223) % plot(I1,'.-');title('加权前I路');xlabel('时间');ylabel('幅度'); % subplot(224) % plot(Q1,&#

11、39;.-');title('加权前Q路');xlabel('时间');ylabel('幅度'); %  % figure(2) % subplot(221) % plot(cos(pi*t/2/Tb),'.-');title('加权函数cos(t/(2Tb)');xlabel('时间');ylabel('幅度') % subplot(222) % plot(sin(pi*t/2/Tb),'.-');title('加权函数sin(t/(2Tb

12、)');xlabel('时间');ylabel('幅度') % subplot(223) % plot(I_out,'.-');title('加权后I路');xlabel('时间');ylabel('幅度'); % subplot(224) % plot(Q_out,'.-');title('加权后Q路');xlabel('时间');ylabel('幅度'); % %* function signal_out,I_out,Q_o

13、ut,phase = mod_msk2(data,data_len,sample_number,Rb) %MSK基带调制 %* % data              调制信号 % data_len          码元个数 % sample_number     每个码元采样点数 % Rb    

14、;            码元速率 % signal_out        基带调制输出 % I_out             I路输出 % Q_out            

15、Q路输出 %*  % data_len = 10;                %码元个数 % sample_number = 8;            %采样点数 % Rb = 16000;           &

16、#160;       %码元速率 % data1 = randint(1,data_len); % data = 2*data1-1;             %传输的序列  Tb = 1/Rb;                 

17、0;    %码元时间 fs = Rb*sample_number;          %采样速率  %- %采样 for i = 1:sample_number     data_sample(i:sample_number:data_len*sample_number) = data; end %*  %- %计算相位 phase = zeros(1,data_len*sample_number); phase(1) =

18、data_sample(1) * pi/2/sample_number; for i = 2:data_len*sample_number     phase(i) = phase(i-1) + data_sample(i-1) * pi/2/sample_number; end %*  %- %I/Q I_out = cos(phase); Q_out = sin(phase); %*  %- %调制信号产生 signal_out = I_out + j*Q_out; %*%MSK调制，差分解调方法一 clear all close all

19、 %- %参数设置 data_len = 10000;           %码元个数 sample_number = 8;          %采样个数 Rb = 24000;                 %码元速率 fc = 960

20、00;                 %载波频率 %*  %- %随机产生传输信号 data=rand_binary(data_len); %*  %- %MSK基带调制 signal_out,I_out,Q_out = mod_msk(data,data_len,sample_number,Rb); %*  %- %中频搬移 multi = fc/Rb; I_temp=interp(I_out,mult

21、i); Q_temp=interp(Q_out,multi);  Fs=fc*sample_number; t=1/Fs:1/Fs:length(I_temp)*1/Fs; signal_i=I_temp.*cos(2*pi*fc*t); signal_q=Q_temp.*sin(2*pi*fc*t); signal_mod=I_temp.*cos(2*pi*fc*t)-Q_temp.*sin(2*pi*fc*t); %*  %- %加噪声 for SNR = 0:8 signal_mod1 = awgn(signal_mod,SNR);    

22、;  %-     %去载波     N=300;                                        

23、      % 滤波器的阶数为(N+1)       F=0,fc-1000,fc+1000,Fs/2*2/Fs;     A=1,1,0,0;     lpf=firls(N,F,A);     amp_lpf,w=freqz(lpf);          I_dem=signal_mod1.*cos(2*pi*fc*t)*2;

24、60;   I_dem=conv(I_dem,lpf);     I_dem=I_dem(N/2+1:N/2+length(I_temp);     Q_dem=signal_mod1.*sin(2*pi*fc*t)*2;     Q_dem=conv(Q_dem,lpf);     Q_dem=-Q_dem(N/2+1:N/2+length(I_temp);          I_de

25、m_out=zeros(1,length(I_dem)/multi);         % 抽取     Q_dem_out=zeros(1,length(Q_dem)/multi);     for i=1:length(I_dem_out)        I_dem_out(i)=I_dem(multi*(i-1)+1);       

26、; Q_dem_out(i)=Q_dem(multi*(i-1)+1);     end;     %*          %-     %差分解调     demod_data = zeros(1,data_len);     demod_data(1) = Q_dem_out(sample_number);     for i = 2:data

27、_len         demod_data(i) = Q_dem_out(i*sample_number)*I_dem_out(i-1)*sample_number) - I_dem_out(i*sample_number)*Q_dem_out(i-1)*sample_number);     end     %*          %-     %判决 

28、0;   demod_data = demod_data>0;     demod_data = 2*demod_data-1;     %*      %-     %计算误码率     num,ber(SNR+1)=symerr(demod_data,data);     %* end %*  %- %误码率曲线 semilogy(0:8,ber,'r*-&#

29、39;); %*  %- %误码率理论值 snr = 0:0.1:8; for i = 1:length(snr)     snr1(1,i) = 10(snr(1,i)/10);     ps(1,i) = 1/2 * erfc(sqrt(snr1(1,i);     pe(1,i) = 2 * ps(1,i); end hold on semilogy(0:.1:8,pe); %*%MSK调制，差分解调方法二 clear all close all  %- %参数设置 data_l

30、en = 10000;           %码元个数 sample_number = 8;          %采样个数 Rb = 24000;                 %码元速率 fc = 96000;   

31、              %载波频率 %*  %- %随机产生传输信号 data=rand_binary(data_len); %*  %- %MSK基带调制 signal_out,I_out,Q_out = mod_msk(data,data_len,sample_number,Rb); %*  %- %中频搬移 multi = fc/Rb; I_temp=interp(I_out,multi); Q_temp=interp(Q_o

32、ut,multi);  Fs=fc*sample_number; t=1/Fs:1/Fs:length(I_temp)*1/Fs; signal_i=I_temp.*cos(2*pi*fc*t); signal_q=Q_temp.*sin(2*pi*fc*t); signal_mod=I_temp.*cos(2*pi*fc*t)-Q_temp.*sin(2*pi*fc*t); %*  %- %加噪声 for SNR = 0:8 signal_mod1 = awgn(signal_mod,SNR);      %-  

33、0;  %去载波     N=300;                                           

34、60;  % 滤波器的阶数为(N+1)       F=0,fc-1000,fc+1000,Fs/2*2/Fs;     A=1,1,0,0;     lpf=firls(N,F,A);     amp_lpf,w=freqz(lpf);          I_dem=signal_mod1.*cos(2*pi*fc*t)*2;     I_dem

35、=conv(I_dem,lpf);     I_dem=I_dem(N/2+1:N/2+length(I_temp);     Q_dem=signal_mod1.*sin(2*pi*fc*t)*2;     Q_dem=conv(Q_dem,lpf);     Q_dem=-Q_dem(N/2+1:N/2+length(I_temp);          I_dem_out=zeros(1,length(

36、I_dem)/multi);         % 抽取     Q_dem_out=zeros(1,length(Q_dem)/multi);     for i=1:length(I_dem_out)        I_dem_out(i)=I_dem(multi*(i-1)+1);        Q_dem_out(i)=Q_dem(

37、multi*(i-1)+1);     end;     %*          %-     %差分解调     demod_data = zeros(1,data_len);     demod_data(1) = Q_dem_out(sample_number);     for i = 2:2:data_len   &#

38、160;     demod_data(i) = -I_dem_out(i*sample_number)*Q_dem_out(i-1)*sample_number);     end     for i = 3:2:data_len         demod_data(i) = Q_dem_out(i*sample_number)*I_dem_out(i-1)*sample_number);   

39、0; end     %*          %-     %判决     demod_data = demod_data>0;     demod_data = 2*demod_data-1;     %*      %-     %计算误码率     num,ber(S

40、NR+1)=symerr(demod_data,data);     %* end %*  %- %误码率曲线 semilogy(0:8,ber,'r*'); %*  %- %误码率理论值 snr = 0:0.1:8; for i = 1:length(snr)     snr1(1,i) = 10(snr(1,i)/10);     ps(1,i) = 1/2 * erfc(sqrt(snr1(1,i);     pe(1,i) = 2

41、* ps(1,i); end hold on semilogy(0:.1:8,pe); %*%MSK调制，解调 clear all close all  %- %参数设置 data_len = 30000;           %码元个数 sample_number = 8;          %采样个数 Rb = 24000;      

42、;           %码元速率 fc = 96000;                 %载波频率 %*  %- %随机产生传输信号 data = rand_binary(data_len); %*  %- %MSK基带调制 signal_out,I_out,Q_out = mod_msk(data,data_le

43、n,sample_number,Rb); %*  %- %中频搬移 multi = fc/Rb; I_temp=interp(I_out,multi); Q_temp=interp(Q_out,multi);  Fs=fc*sample_number; t=1/Fs:1/Fs:length(I_temp)*1/Fs; signal_i=I_temp.*cos(2*pi*fc*t); signal_q=Q_temp.*sin(2*pi*fc*t); signal_mod=I_temp.*cos(2*pi*fc*t)-Q_temp.*sin(2*pi*fc*t); % sign

44、al_mod1=real(I_temp+j*Q_temp).*exp(j*2*pi*fc*t); %*  %- %加噪声 for SNR = 0:8 signal_mod1 = 0.01 * awgn(signal_mod,SNR);      %-     %去载波     N=300;                

45、0;                             % 滤波器的阶数为(N+1)       F=0,fc-1000,fc+1000,Fs/2*2/Fs;     A=1,1,0,0;     lpf

46、=firls(N,F,A);     amp_lpf,w=freqz(lpf);          I_dem=signal_mod1.*cos(2*pi*fc*t)*2 .* cos(pi*t*Rb/2);     I_dem=conv(I_dem,lpf);     I_dem=I_dem(N/2+1:N/2+length(I_temp);     Q_dem=signal_mod1.*sin(2*pi

47、*fc*t)*2 .* sin(pi*t*Rb/2);     Q_dem=conv(Q_dem,lpf);     Q_dem=-Q_dem(N/2+1:N/2+length(I_temp);          I_dem_out=zeros(1,length(I_dem)/multi);         % 抽取     Q_dem_out=zeros(

48、1,length(Q_dem)/multi);     for i=1:length(I_dem_out)        I_dem_out(i)=I_dem(multi*(i-1)+1);        Q_dem_out(i)=Q_dem(multi*(i-1)+1);     end;         %*    

49、;  %-     %解调，判决     demod_data = zeros(1,data_len);     for i = 1:data_len         I_dem1(i) = I_dem_out(i*sample_number)>0;         Q_dem1(i) = Q_dem_out(i*sample_number)>0;     end     for i = 1:2:data_len         m1(i) = Q_dem1(i);   &#