ray_function.m

这是个扩频系统中的PN码仿真程序

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%此程序为正确程序
% Richard Wyrwas, 2 February 1995.
% plot labels added by Bill Cowley  4/97
function R=RAY(ns,fm,fs)
%fs为取样频率(Hz)
%fm为多谱勒频移(Hz)
%ns为总的取样值(ge)
%disp('ray2: Jakes method: calculating weighted quadrature sinusoids  ....');
%disp('with Fs =1kHz ');

% ns=3000;fm=0.5;fs=1000;
j=sqrt(-1);
R=zeros(ns,1);
Mag=zeros(ns,1);
for x=1:ns
      tm=x/fs;
      I=0.0;
      I=1.848*cos(0.983*2*pi*fm*tm);
      I=I+1.414*cos(0.932*2*pi*fm*tm);
      I=I+0.765*cos(0.850*2*pi*fm*tm);
      I=I+0.0*cos(0.739*2*pi*fm*tm);
      I=I-0.765*cos(0.603*2*pi*fm*tm);
      I=I-1.414*cos(0.446*2*pi*fm*tm);
      I=I-1.848*cos(0.247*2*pi*fm*tm);
      I=I-2.000*cos(0.092*2*pi*fm*tm);
      I=I+1.000*cos(1.000*2*pi*fm*tm);

      Q=0.0;
      Q=Q+0.765*cos(0.983*2*pi*fm*tm);
      Q=Q+1.414*cos(0.932*2*pi*fm*tm);
      Q=Q+1.848*cos(0.850*2*pi*fm*tm);
      Q=Q+2.000*cos(0.739*2*pi*fm*tm);
      Q=Q+1.848*cos(0.603*2*pi*fm*tm);
      Q=Q+1.414*cos(0.446*2*pi*fm*tm);
      Q=Q+0.765*cos(0.247*2*pi*fm*tm);
      Q=Q+0.000*cos(0.092*2*pi*fm*tm);
      Q=Q+1.000*cos(1.000*2*pi*fm*tm);
     
      
      R(x) = 0.227*I+j*Q*0.227;
      Mag(x)=abs(R(x));

end;
% plot(Mag);