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Diffstat (limited to 'gsm-receiver/src/lib/gsm_constants.h')
| -rw-r--r-- | gsm-receiver/src/lib/gsm_constants.h | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/gsm-receiver/src/lib/gsm_constants.h b/gsm-receiver/src/lib/gsm_constants.h new file mode 100644 index 0000000..939099d --- /dev/null +++ b/gsm-receiver/src/lib/gsm_constants.h @@ -0,0 +1,150 @@ +#ifndef INCLUDED_GSM_CONSTANTS_H +#define INCLUDED_GSM_CONSTANTS_H + +#define GSM_SYMBOL_RATE (1625000.0/6.0) //symbols per second +#define GSM_SYMBOL_PERIOD (1.0/GSM_SYMBOL_RATE) //seconds per symbol + +//Burst timing +#define TAIL_BITS 3 +#define GUARD_BITS 8 +#define GUARD_FRACTIONAL 0.25 //fractional part of guard period +#define GUARD_PERIOD GUARD_BITS + GUARD_FRACTIONAL +#define DATA_BITS 57 //size of 1 data block in normal burst +#define STEALING_BIT 1 +#define N_TRAIN_BITS 26 +#define N_SYNC_BITS 64 +#define USEFUL_BITS 142 //(2*(DATA_BITS+STEALING_BIT) + N_TRAIN_BITS ) +#define FCCH_BITS USEFUL_BITS +#define BURST_SIZE (USEFUL_BITS+2*TAIL_BITS) + +#define SCH_DATA_LEN 39 +#define TS_BITS (TAIL_BITS+USEFUL_BITS+TAIL_BITS+GUARD_BITS) //a full TS (156 bits) +#define TS_PER_FRAME 8 +#define FRAME_BITS (TS_PER_FRAME * TS_BITS + 2) // 156.25 * 8 +#define FCCH_POS TAIL_BITS +#define SYNC_POS 39 +#define TRAIN_POS ( TAIL_BITS + (DATA_BITS+STEALING_BIT) + 5) //first 5 bits of a training sequence + //aren't used for channel impulse response estimation +#define TRAIN_BEGINNING 5 +#define SAFETY_MARGIN 6 // + +#define FCCH_HITS_NEEDED (USEFUL_BITS - 4) +#define FCCH_MAX_MISSES 1 +#define FCCH_MAX_FREQ_OFFSET 100 + +#define CHAN_IMP_RESP_LENGTH 5 + +#define MAX_SCH_ERRORS 5 //maximum number of subsequent sch errors after which gsm receiver goes to find_next_fcch state + +typedef enum {empty, fcch_burst, sch_burst, normal_burst, rach_burst, dummy, dummy_or_normal} burst_type; +typedef enum {unknown, multiframe_26, multiframe_51} multiframe_type; + +static const unsigned char SYNC_BITS[] = { + 1, 0, 1, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 1, 0, + 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, + 0, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, + 0, 1, 1, 1, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 1, 1 +}; + +const unsigned FCCH_FRAMES[] = {0, 10, 20, 30, 40}; +const unsigned SCH_FRAMES[] = {1, 11, 21, 31, 41}; + +const unsigned BCCH_FRAMES[] = {2, 3, 4, 5}; //!!the receiver shouldn't care about logical + //!!channels so this will be removed from this header +const unsigned TEST_CCH_FRAMES[] = {2, 3, 4, 5, 6, 7, 8, 9, 12, 13, 14, 15, 16, 17, 18, 19, 22, 23, 24, 25, 26, 27, 28, 29, 32, 33, 34, 35, 36, 37, 38, 39, 42, 43, 44, 45, 46, 47, 48, 49}; +const unsigned TRAFFIC_CHANNEL_F[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24}; +const unsigned TEST51[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50}; + + +#define TSC0 0 +#define TSC1 1 +#define TSC2 2 +#define TSC3 3 +#define TSC4 4 +#define TSC5 5 +#define TSC6 6 +#define TSC7 7 +#define TS_DUMMY 8 + +#define TRAIN_SEQ_NUM 9 + +#define TIMESLOT0 0 +#define TIMESLOT1 1 +#define TIMESLOT2 2 +#define TIMESLOT3 3 +#define TIMESLOT4 4 +#define TIMESLOT5 5 +#define TIMESLOT6 6 +#define TIMESLOT7 7 + + +static const unsigned char train_seq[TRAIN_SEQ_NUM][N_TRAIN_BITS] = { + {0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1}, + {0, 0, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1}, + {0, 1, 0, 0, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 1, 1, 0}, + {0, 1, 0, 0, 0, 1, 1, 1, 1, 0, 1, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 1, 1, 0}, + {0, 0, 0, 1, 1, 0, 1, 0, 1, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 1, 0, 1, 0, 1, 1}, + {0, 1, 0, 0, 1, 1, 1, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 1, 0, 1, 0}, + {1, 0, 1, 0, 0, 1, 1, 1, 1, 1, 0, 1, 1, 0, 0, 0, 1, 0, 1, 0, 0, 1, 1, 1, 1, 1}, + {1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0}, + {0, 1, 1, 1, 0, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 1, 0, 1} // DUMMY +}; + + +//Dummy burst 0xFB 76 0A 4E 09 10 1F 1C 5C 5C 57 4A 33 39 E9 F1 2F A8 +static const unsigned char dummy_burst[] = { + 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, + 1, 1, 0, 1, 1, 0, 0, 0, 0, 0, + 1, 0, 1, 0, 0, 1, 0, 0, 1, 1, + 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, + 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, + 0, 1, 1, 1, 1, 1, 0, 0, + + 0, 1, 1, 1, 0, 0, 0, 1, 0, 1, + 1, 1, 0, 0, 0, 1, 0, 1, 1, 1, + 0, 0, 0, 1, 0, 1, + + 0, 1, 1, 1, 0, 1, 0, 0, 1, 0, + 1, 0, 0, 0, 1, 1, 0, 0, 1, 1, + 0, 0, 1, 1, 1, 0, 0, 1, 1, 1, + 1, 0, 1, 0, 0, 1, 1, 1, 1, 1, + 0, 0, 0, 1, 0, 0, 1, 0, 1, 1, + 1, 1, 1, 0, 1, 0, 1, 0 +}; + + +/* + * The frequency correction burst is used for frequency synchronization + * of the mobile. This is broadcast in TS0 together with the SCH and + * BCCH. + * + * Modulating the bits below causes a spike at 62.5kHz above (below for + * COMPACT) the center frequency. One can use this spike with a narrow + * band filter to accurately determine the center of the channel. + */ +static const unsigned char fc_fb[] = { //I don't use this tables, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //I copied this here from burst_types.h because + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, //the description is very informative - p.krysik + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 +}; + +static const unsigned char fc_compact_fb[] = { + 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, + 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, + 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, + 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, + 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, + 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, + 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, + 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, + 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0 +}; + + +#endif /* INCLUDED_GSM_CONSTANTS_H */ |