%spectrum spread and modulation
Rb=100000;%100kb/s
Rc=Rb*15;%1.5Mb/s chip rate
Fc=Rc*2;%3M/s carrier frequence
W=Rc;%band width
Fs=Fc*10;
SpB=Fs/Rb;
%x=floor(rand(4,1)*2);
N=1000;
%x=[1;1;0;1];
x=floor(rand(1,N)*2);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
x_1=x*2-1;
%PN=floor(rand(1,15)*2);
PN=[1 0 0 1 1,0 1 1 1 0,1 0 0 0 1];
PN_1=PN*2-1;
[PN_2,x_2]=meshgrid(PN_1,x_1);
x_spread=x_2.*PN_2;
[h ,w]=size(x_spread);
x_t=reshape(x_spread',h*w,1);%chips
sample=1:Fs/Rc;
[sample1 x_tl]=meshgrid(sample,x_t);%對x_t進行采樣得到的采樣點
x_tls=reshape(x_tl',1,h*w*Fs/Rc);%采樣點的序列
t=1/Fs:1/Fs:1/Rb*N;
%modulate
tc=1/Fs:1/Fs:1/Rc;
ftc=cos(2*pi*Fc*tc);
[ftc_1 x_t4]=meshgrid(ftc,x_t);
xt_modu=ftc_1.*x_tl;
xt_modu_l=reshape(xt_modu',1,h*w*Fs/Rc);
[F_m f_m]=gen_spectrum(xt_modu_l,Fs);%調制后的頻譜
[F_l,f_l]=gen_spectrum(x_tls,Fs);%低通信號的頻譜
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%plot(f_m,F_m);