utility.c

This model is just testing an idea of MIMO, which IEEE802.11n will have. But I havo not seen the s

/*****************************************************************************/
/*   FIle Name : utility.c                                                   */
/*   Description : utilities                                                 */
/*                 int_random                                                */
/*   author : miffie                                                         */
/*   Date   : aug/09/05                                                      */
/*   Copyright (c) 2005 miffie   All rights reserved.                        */
/*****************************************************************************/

int int_random (int max) {
double aa , bb ;
int cc ;

  aa = rand() ;
  bb = RAND_MAX  ;
  aa = aa / bb ;
  aa = aa * max ;
  cc = floor( aa ) ;
  return ( cc );
} //int_random

int gamma_random (int max) {
double aa ;
int cc ;
double GAMMA = 2 ;

  aa = ((double) rand())/RAND_MAX ;
  //0<= aa <=1
  aa = max * pow(aa , GAMMA) ;
  cc = floor( aa ) ;
  return ( cc );
} //gamma_random

int pow_random (int max, double gamma) {
double aa ;
int cc ;

  aa = ((double) rand())/RAND_MAX ;
  //0<= aa <=1
  aa = max * pow(aa , gamma) ;
  cc = floor( aa ) ;
  return ( cc );
} //pow_random

double iir_lpf(double input, double reg, double coeff) {
  double output , newreg ;

  output = reg+ (input-reg)*coeff ; 
  printf("lpf input = %8.5f output=%8.5f\n", input, output ) ;
  return (output) ;
}