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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 输入信号 %data_diff 差分编码后信号 %* %- data_diff
2、= 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_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 码元速率 % signal_out 基带
3、调制输出 % I_out I路输出 % Q_out Q路输出 %* % data_len = 10; %码元个数 % sample_number = 8; %采样点数 % Rb = 16000; %码元速率 % data1 = randint(1,data_len); % 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 = difference(data); %* %- %并串转换，延时 I(1) = 1; %fai0 = 0,cos(fai0) = 1 for
4、i = 1:2:data_len 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); Q1(i:sample_number:data_len*sample_number) = Q(1:data_len); end %* %- %乘加权函数 t=1/f
5、s: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(MSK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
6、(I1,.-);title(加权前I路);xlabel(时间);ylabel(幅度); % subplot(224) % plot(Q1,.-);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);xlabel(时间);ylabel(幅度) % subpl
7、ot(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_out,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 码元速率 % signal_o
8、ut 基带调制输出 % I_out I路输出 % Q_out Q路输出 %* % data_len = 10; %码元个数 % sample_number = 8; %采样点数 % Rb = 16000; %码元速率 % data1 = randint(1,data_len); % data = 2*data1-1; %传输的序列 Tb = 1/Rb; %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) = 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 %* %-
