test5.m

伪随机码

%%%%%%%%%%%%%%%扩频通信--加载波发射为随机码%%%%%%%%%%%%%%%%%%


close all;
clear all;
clc;


fs1=3e3;%带宽
fs3=15e3;%采样频率
fs2=4.5e3;%载波频率
m=10;%伪码m
tb1=1/fs1;
tb2=1/fs2;
tb3=1/fs3;

f02=pcode1(m);%产生m阶为随机序列
% f02 = -1*f02;
% f03 = f02;
% for i =1:1:10
%     f03 = [f03 , f02];
% end
% figure
% plot(xcorr(f03,f02));
% break;

figure
plot(f02);

shuzi1=[49:1:52];%传输的信息

[code1]=product1(shuzi1);%把信息转化成2进制
%%%%%%%%%%%%%%%添加同步头和同步尾%%%%%%%%
head1=[1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0];
end1=[0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1];
code2 = [head1 code1];
code2=[code2,end1];
clear head1;
clear code1;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
figure
plot(code2)

[mod2]=modtion2(f02,code2);%通信信息用为随机码来调制

figure
plot(mod2)

[mod3,num2]=dpsk1(mod2);%2DPSK调制

[mod4]=modtion3(mod3,tb1,tb3,fs1,fs3);%内插5个点

figure
plot(mod4)
clear mod3;
 
[tz1,sin5k]=modtion1(mod4,tb1,tb2,tb3,fs2,fs3);%正弦调制

figure
plot(tz1)
%%%%%%%%%%%%%%%%%%%%%读取音乐文件并归一化%%%%%%
num6=length(tz1);
wavfile = 'D:\我的研究\扩频通信之顾\语音扩频通信\发射的数据文件\last_181.wav';
[y,fs3 , nbits] = wavread(wavfile);
y=y.';
y = y(1,:);
y=y(1:num6);
y_max=max(abs(y));
y=y./y_max;
y_number=length(y);

x=abs(fft((tz1(1,1:1.6e4))));
x=10*log10(x);
figure 
plot(x); 
tz2 = tz1(1:y_number) + y(1:y_number);%1.*%信号和音乐相加
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%%%写入文件%%%%%%%%%%%%%%%%%%

% filename = 'send_1.wav';
% wavwrite(tz2,fs3,filename);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

 wavplay(tz2,fs3);%播放文件