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NXDN - Rolling CAC CRC fix (reset demodulator state); Scrambler SEED Fix Each PF;

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lwvmobile
2024-02-14 18:03:07 -05:00
parent 4324afc593
commit c401035209
2 changed files with 92 additions and 7 deletions
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89
src/nxdn_deperm.c
View File

@@ -280,6 +280,8 @@ void nxdn_deperm_sacch(dsd_opts * opts, dsd_state * state, uint8_t bits[60])
}
fprintf (stderr, "PF 1/1");
if (state->nxdn_cipher_type == 1 && state->R != 0) state->payload_miN = state->R; //reset scrambler seed
else if (state->M == 1 && state->R != 0) state->payload_miN = state->R; //force reset scrambler seed
if (crc == check) NXDN_Elements_Content_decode(opts, state, 1, nsf_sacch);
// else if (opts->aggressive_framesync == 0) NXDN_Elements_Content_decode(opts, state, 0, nsf_sacch);
@@ -331,6 +333,11 @@ void nxdn_deperm_sacch(dsd_opts * opts, dsd_state * state, uint8_t bits[60])
fprintf (stderr, "%s", KNRM);
fprintf (stderr, "PF %d/4", part_of_frame+1);
if (part_of_frame == 0)
{
if (state->nxdn_cipher_type == 1 && state->R != 0) state->payload_miN = state->R; //reset scrambler seed
else if (state->M == 1 && state->R != 0) state->payload_miN = state->R; //force reset scrambler seed
}
// if (crc != check)
// {
@@ -340,7 +347,33 @@ void nxdn_deperm_sacch(dsd_opts * opts, dsd_state * state, uint8_t bits[60])
// }
//reset scrambler seed to key value on new superframe
if (part_of_frame == 0 && state->nxdn_cipher_type == 0x1) state->payload_miN = 0;
// if (part_of_frame == 0 && state->nxdn_cipher_type == 0x1) state->payload_miN = 0;
//reset scrambler seed to key value on new superframe
if (part_of_frame == 0 && state->nxdn_cipher_type == 0x1)
{
if (state->nxdn_cipher_type == 1 && state->R != 0) state->payload_miN = state->R; //reset scrambler seed
else if (state->M == 1 && state->R != 0) state->payload_miN = state->R; //force reset scrambler seed
}
//this seems to work much better now
else if (part_of_frame != 0 && state->nxdn_cipher_type == 0x1)
{
if (state->nxdn_cipher_type == 1 && state->R != 0) state->payload_miN = state->R; //reset scrambler seed
else if (state->M == 1 && state->R != 0) state->payload_miN = state->R; //force reset scrambler seed
//advance seed by required number of turns depending on the current pf value
int start = 0; int end = part_of_frame;
char ambe_temp[49] = {0};
char ambe_d[49] = {0};
for (start = 0; start < end; start++)
{
//run 4 times
LFSRN(ambe_temp, ambe_d, state);
LFSRN(ambe_temp, ambe_d, state);
LFSRN(ambe_temp, ambe_d, state);
LFSRN(ambe_temp, ambe_d, state);
}
}
if (crc == check)
{
@@ -568,7 +601,7 @@ void nxdn_deperm_facch2_udch(dsd_opts * opts, dsd_state * state, uint8_t bits[34
}
}
static int cac_fail = 0;
void nxdn_deperm_cac(dsd_opts * opts, dsd_state * state, uint8_t bits[300])
{
uint8_t deperm[300]; //300
@@ -684,6 +717,49 @@ void nxdn_deperm_cac(dsd_opts * opts, dsd_state * state, uint8_t bits[300])
fprintf (stderr, "%s", KNRM);
}
//check for accumulative cac failures and reset if multiple errors pile up
//(LZ issue and also issue very occasssionally noticed on remote)
if (crc != 0) cac_fail++;
else cac_fail = 0;
//reset some parameters if CAC continues to fail
if (cac_fail >= 5)
{
//simple reset
state->synctype = 0;
state->lastsynctype = -1;
state->carrier = 0;
state->last_cc_sync_time = time(NULL)+2; //probably not necesary
cac_fail = 0; //reset
//more advanced modulator reset
state->center = 0;
state->jitter = -1;
state->synctype = -1;
state->min = -15000;
state->max = 15000;
state->lmid = 0;
state->umid = 0;
state->minref = -12000;
state->maxref = 12000;
state->lastsample = 0;
for (int i = 0; i < 128; i++) state->sbuf[i] = 0;
state->sidx = 0;
for (int i = 0; i < 1024; i++) state->maxbuf[i] = 15000;
for (int i = 0; i < 1024; i++) state->minbuf[i] = -15000;
state->midx = 0;
state->symbolcnt = 0;
//reset the dibit buffer
state->dibit_buf_p = state->dibit_buf + 200;
memset (state->dibit_buf, 0, sizeof (int) * 200);
state->offset = 0;
//debug notification
// fprintf (stderr, " RESET CARRIER; ");
}
if (crc == 0) NXDN_Elements_Content_decode(opts, state, 1, cac_message_buffer);
// else if (opts->aggressive_framesync == 0) NXDN_Elements_Content_decode(opts, state, 0, cac_message_buffer);
@@ -816,7 +892,14 @@ void nxdn_deperm_scch(dsd_opts * opts, dsd_state * state, uint8_t bits[60], uint
else part_of_frame = 0;
//reset scrambler seed to key value on new superframe
if (part_of_frame == 0 && state->nxdn_cipher_type == 0x1) state->payload_miN = 0;
// if (part_of_frame == 0 && state->nxdn_cipher_type == 0x1) state->payload_miN = 0;
//reset scrambler seed to key value on new superframe
if (part_of_frame == 0 && state->nxdn_cipher_type == 0x1)
{
if (state->nxdn_cipher_type == 1 && state->R != 0) state->payload_miN = state->R; //reset scrambler seed
else if (state->M == 1 && state->R != 0) state->payload_miN = state->R; //force reset scrambler seed
}
/*
4.3.2. Mapping to Functional Channel

10
src/nxdn_element.c
View File

@@ -150,9 +150,9 @@ void NXDN_Elements_Content_decode(dsd_opts * opts, dsd_state * state,
NXDN_decode_VCALL(opts, state, ElementsContent);
memset (state->nxdn_alias_block_segment, 0, sizeof(state->nxdn_alias_block_segment));
#ifdef LIMAZULUTWEAKS
; //do nothing -- testing errors on CAC messages when returning quickly from RTCH
#else
// #ifdef LIMAZULUTWEAKS
// ; //do nothing -- testing errors on CAC messages when returning quickly from RTCH
// #else
//tune back to CC here - save about 1-2 seconds
if (opts->p25_trunk == 1 && state->p25_cc_freq != 0 && opts->p25_is_tuned == 1)
@@ -197,7 +197,7 @@ void NXDN_Elements_Content_decode(dsd_opts * opts, dsd_state * state,
state->last_cc_sync_time = time(NULL); //allow tuners a second to catch up, particularly rtl input
}
#endif
// #endif
break;
//Idle
@@ -654,6 +654,7 @@ void NXDN_decode_VCALL_ASSGN(dsd_opts * opts, dsd_state * state, uint8_t * Messa
state->R = state->rkey_array[DestinationID];
fprintf (stderr, " %s", KYEL);
fprintf (stderr, " Key Loaded: %lld", state->rkey_array[DestinationID]);
state->payload_miN = state->R; //should be okay to load here, will test
}
if (state->M == 1) state->nxdn_cipher_type = 0x1;
}
@@ -687,6 +688,7 @@ void NXDN_decode_VCALL_ASSGN(dsd_opts * opts, dsd_state * state, uint8_t * Messa
state->R = state->rkey_array[DestinationID];
fprintf (stderr, " %s", KYEL);
fprintf (stderr, " Key Loaded: %lld", state->rkey_array[DestinationID]);
state->payload_miN = state->R; //should be okay to load here, will test
}
if (state->M == 1) state->nxdn_cipher_type = 0x1;
#endif