rayleigh.m

来自「PHS多天线基带调制与解调MATLAB程序」· M 代码 · 共 60 行

function r = rayleigh(doppler,rate,N,M)




      fs = 2 * doppler ;

      LCM = lcm(fs,rate) ;
      
      kInt = LCM / fs ;

      kDec = LCM / rate ;

      df = fs / N ; 


      f = -doppler + df : df : doppler - df ;


      S = sqrt(1.5 ./ (pi * doppler * sqrt(1 - (f / doppler).^2))) ;

      sNeg = 2*S(1)-S(2) ;
      S = [ sNeg S ] ;


       I = randn(1,N/2-1) + j * randn(1,N/2-1) ;

       Q = randn(1,N/2-1) + j * randn(1,N/2-1) ;

       I = [ randn conj(I(N/2-1:-1:1)) randn I ] ;

       Q = [ randn conj(Q(N/2-1:-1:1)) randn Q ] ;


      filt_I = S .* I ;
      filt_Q = S .* Q ;

      filt_I = [ filt_I(N/2+1:N) filt_I(1:N/2) ] ; 
      filt_Q = [ filt_Q(N/2+1:N) filt_Q(1:N/2) ] ; 


      x = ifft(filt_I) ;
      y = ifft(filt_Q) ;

      x = real(x) ;
      y = real(y) ;
      r = x + j * y ;
      nr = max(9,ceil(M*kDec/kInt)) ;
      r = r(1:nr) ;


      r = interp(r,kInt) ;


      r = decimate(r,kDec) ;
      r = r(1:M) ;


      r = r / sqrt(mean(r .* conj(r))) ;