void adc(double *r_re[2],
         double *r_im[2],
         unsigned int input_offset,
         unsigned int output_offset,
         unsigned int **output,
         unsigned int nb_rx_antennas,
         unsigned int length,
         unsigned char B)
{

  int i;
  int aa;
  double gain = (double)(1<<(B-1));
  //double gain = 1.0;

  for (i=0; i<length; i++) {
    for (aa=0; aa<nb_rx_antennas; aa++) {
      ((short *)output[aa])[((i+output_offset)<<1)]   = (short)(r_re[aa][i+input_offset]*gain);
      ((short *)output[aa])[1+((i+output_offset)<<1)] = (short)(r_im[aa][i+input_offset]*gain);

      if ((r_re[aa][i+input_offset]*gain) > 30000) {
        //("Adc outputs %d %e  %d \n",i,((short *)output[0])[((i+output_offset)<<1)], ((i+output_offset)<<1) );
      }
    }

    //printf("Adc outputs %d %e  %d \n",i,((short *)output[0])[((i+output_offset)<<1)], ((i+output_offset)<<1) );
  }
}