Matlab实现MSK调制解调与信号处理详解

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 = 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 i = 1:2:data_len