CDMA 作业

fu.f..hmtmnsfngnhmk,i,yuhnhnhng t tnyntnt ht th th h fd d g sÆ°  Æ° r r th ttt f sv   Æ° %DS spread signal  DS=kron(data,ds);%length Ns*Nc  ( kron: Kronecker product, element matrices of  kron(A,B) are A(i,j)B )  ----------------------------------------------  %plot first 2 symbols of ds-modulated signal  if l==1 & k==1  plot([real(DS) imag(DS)]),title("2 symbols of DS  modulated signal"),  axis([0 2*Nc -1/sqrt(Nc) 1/sqrt(Nc)]),pause,  end  -------------------------------------------------  %CHANNELS  %This is the place to set SNR.  %Since symbol energy is 1 and noise variance is 1,  %SNR of symbol/noise sample is 0 dB.  %Thus, we have to multiply symbol or divide noise  to obtain desired SNR.