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// $Id: bursts.cc,v 1.1.1.1 2007-06-01 04:26:57 jl Exp $
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include "burst_types.h"
void display_burst_type(burst_t t) {
switch(t) {
case burst_n_0:
case burst_n_1:
case burst_n_2:
case burst_n_3:
case burst_n_4:
case burst_n_5:
case burst_n_6:
case burst_n_7:
printf("normal burst %d", t);
break;
case burst_fc:
printf("frequency correction burst");
break;
case burst_fc_c:
printf("frequency correction burst (COMPACT)");
break;
case burst_s:
printf("synchronization burst");
break;
case burst_s_cts:
printf("synchronization burst (CTS)");
break;
case burst_s_c:
printf("synchronization burst (COMPACT)");
break;
case burst_d:
printf("dummy burst");
break;
case burst_a:
printf("access burst");
break;
case burst_a_ts1:
printf("access burst (TS1)");
break;
case burst_a_ts2:
printf("access burst (TS2)");
break;
default:
printf("unknown burst type");
break;
}
}
static int burst_diff(const unsigned char *b1, const unsigned char *b2,
unsigned int l) {
int d = 0;
unsigned int i;
for(i = 0; i < l; i++)
d += (b1[i] ^ b2[i]);
return d;
}
int search_fc(unsigned char *buf) {
return !(burst_diff(buf + TB_OS1, tail_bits, TB_LEN) +
burst_diff(buf + TB_OS2, tail_bits, TB_LEN) +
burst_diff(buf + FC_OS, fc_fb, FC_CODE_LEN));
}
int is_dummy_burst(const unsigned char *buf) {
int i;
for(i = 0; i < D_CODE_LEN; i++)
if(buf[i + D_MB_OS] != d_mb[i])
return 0;
return 1;
}
burst_t search_burst(unsigned char *buf, int max_burst_errors, int *rmin_o) {
int i, d_burst[N_BURST_TYPES], t_d, d_min, rmin;
burst_t bt_min;
for(i = 0; i < N_BURST_TYPES; i++)
d_burst[i] = max_burst_errors + 1;
// access burst (uplink only)
t_d = burst_diff(buf + AB_ETB_OS, ab_etb, AB_ETB_CODE_LEN);
d_burst[(int)burst_a] =
t_d + burst_diff(buf + AB_SSB_OS, ab_ssb, AB_SSB_CODE_LEN);
d_burst[(int)burst_a_ts1] =
t_d + burst_diff(buf + AB_SSB_OS, ab_ts1_ssb, AB_SSB_CODE_LEN);
d_burst[(int)burst_a_ts2] =
t_d + burst_diff(buf + AB_SSB_OS, ab_ts2_ssb, AB_SSB_CODE_LEN);
// check tail bits
t_d =
burst_diff(buf + TB_OS1, tail_bits, TB_LEN) +
burst_diff(buf + TB_OS2, tail_bits, TB_LEN);
// normal bursts
for(i = 0; i < N_TSC_NUM; i++)
d_burst[(int)burst_n_0 + i] =
t_d + burst_diff(buf + N_TSC_OS, n_tsc[i], N_TSC_CODE_LEN);
// frequency correction
d_burst[(int)burst_fc] =
t_d + burst_diff(buf + FC_OS, fc_fb, FC_CODE_LEN);
d_burst[(int)burst_fc_c] =
t_d + burst_diff(buf + FC_OS, fc_compact_fb, FC_CODE_LEN);
// synchronization burst
d_burst[(int)burst_s] =
t_d + burst_diff(buf + SB_ETS_OS, sb_etsc, SB_CODE_LEN);
d_burst[(int)burst_s_cts] =
t_d + burst_diff(buf + SB_ETS_OS, sb_cts_etsc, SB_CODE_LEN);
d_burst[(int)burst_s_c] =
t_d + burst_diff(buf + SB_ETS_OS, sb_compact_etsc, SB_CODE_LEN);
// dummy
d_burst[(int)burst_d] =
t_d + burst_diff(buf + D_MB_OS, d_mb, D_CODE_LEN);
d_burst[(int)burst_not_a_burst] = max_burst_errors;
rmin = BURST_LENGTH;
d_min = max_burst_errors + 1;
bt_min = burst_not_a_burst;
for(i = 0; i < N_BURST_TYPES; i++) {
if(d_burst[i] < d_min) {
bt_min = (burst_t)i;
d_min = d_burst[i];
}
if((d_burst[i] < rmin) && ((burst_t)i != burst_not_a_burst))
rmin = d_burst[i];
}
if(rmin_o)
*rmin_o = rmin;
return bt_min;
}
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