fft_demodulation.h

it is a program about ofdm,and it is programed on dsk6455

void FFT_Modulation(short *receive,int *buffer_QAM1,int *y)
{
  int i,j;
  int A;
  int N_symbol;
  A=QAM_buffer_len%data_per_symbol;
  if(A==0)  N_symbol=floor((float)buffer_QAM_len/(float)data_per_symbol);
  else      N_symbol=floor((float)buffer_QAM_len/(float)data_per_symbol)+1;
  for(i=0;i<61440;i++)
    {
	  receive[i]=signal[i+3764];
	}
  for(j=0;j<N_symbol;j++)
   {
     for(i=0;i<2*FFT_Size;i++)
      {
        /*
        y[2*i]=receive[(FFT_Size+CP_len)*j+i+CP_len];
		y[2*i+1]=0;
		*/
		y[i]=receive[2*(FFT_Size+CP_len)*j+i+2*CP_len];
       }
	 DSP_fft16x32(w,FFT_Size,y,x);
     for(i=0;i<2*data_per_symbol;i++)
      {
        buffer_QAM1[j*2*data_per_symbol+i]=x[i+2*Carrier_Start];
       }
   }
  return;
}