eee_scenario_x/descrambler.c

/*
 * Academic License - for use in teaching, academic research, and meeting
 * course requirements at degree granting institutions only.  Not for
 * government, commercial, or other organizational use.
 *
 * descrambler.c
 *
 * Code generation for function 'descrambler'
 *
 */

/* Include files */
#include <math.h>
#include <string.h>
#include "descrambler.h"

/* Function Definitions */
void descramble(double *value, double t, const double B1[9], const double A1[9],
                 const double B2[19], const double A2[19], double Z1[8], double
                 Z2[18])
{
  double b[9];
  double a[9];
  double a1;
  int k;
  double zf[8];
  double b_b[19];
  double b_a[19];
  double b_zf[18];

  /*  Filter to remove 8kHz tone */
  memcpy(&b[0], &B1[0], 9U * sizeof(double));
  memcpy(&a[0], &A1[0], 9U * sizeof(double));
  a1 = A1[0];
  if ((!(A1[0] == 0.0)) && (A1[0] != 1.0)) {
    for (k = 0; k < 9; k++) {
      b[k] /= a1;
    }
    for (k = 0; k < 8; k++) {
      a[k + 1] /= a1;
    }
    a[0] = 1.0;
  }

  memset(&zf[0], 0, sizeof(double) << 3);
  a1 = Z1[0] + *value * b[0];
  for (k = 0; k < 7; k++) {
    zf[k] = Z1[k + 1];
  }

  for (k = 0; k < 8; k++) {
    Z1[k] = (zf[k] + *value * b[k + 1]) + -a1 * a[k + 1];
  }

  /*  Shifting by 7kHz */
  *value = a1 * 2.0 * sin(6.2831853071795862 * t * 7000.0);

  /*  Low pass filter */
  memcpy(&b_b[0], &B2[0], 19U * sizeof(double));
  memcpy(&b_a[0], &A2[0], 19U * sizeof(double));
  a1 = A2[0];
  if ((!(A2[0] == 0.0)) && (A2[0] != 1.0)) {
    for (k = 0; k < 19; k++) {
      b_b[k] /= a1;
    }
    for (k = 0; k < 18; k++) {
      b_a[k + 1] /= a1;
    }
    b_a[0] = 1.0;
  }

  memset(&b_zf[0], 0, 18U * sizeof(double));
  a1 = Z2[0] + *value * b_b[0];
  memcpy(&b_zf[0], &Z2[1], 17U * sizeof(double));
  for (k = 0; k < 18; k++) {
    Z2[k] = (b_zf[k] + *value * b_b[k + 1]) + -a1 * b_a[k + 1];
  }
  *value = a1;
}

/* End of code generation (descrambler.c) */