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Merge remote-tracking branch 'origin/ntn_continuous_sib19_updates' into integration_2025_w27 (!3398)

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continuously update SIB19 information for rfsim NTN LEO scenarios

Contains mainly these changes:

- gNB: add function nr_update_sib19() allowing to update SIB19
  information
- rfsimulator: update SIB19 contents every frame for LEO channel
  simulations
- NR UE: improve initial timing advance calculation from SIB19

Before, we only considered ta_Common_r17 and the SAT position from SIB19
to compute the initial timing advance value. This is good enough if the
satellite does not move too fast (e.g. GEO satellite).

Now we also consider ta_CommonDrift_r17, ta_CommonDriftVariant_r17 and
the SAT velocity together with the epoch time from SIB19. This improves
the accuracy of the initial TA computation, esp. for LEO satellite
scenarios.
This commit is contained in:
Robert Schmidt
2025-07-04 09:42:19 +02:00
parent 105d4f6dfb 7b991c4dbf
commit 06a5166f17
17 changed files with 350 additions and 81 deletions
Download Patch File Download Diff File Expand all files Collapse all files
executables/nr-ue.c
+36 -17
View File
@@ -908,7 +908,8 @@ static inline int get_readBlockSize(uint16_t slot, NR_DL_FRAME_PARMS *fp) {
static inline void apply_ntn_config(PHY_VARS_NR_UE *UE,
NR_DL_FRAME_PARMS *fp,
int slot_nr,
int frame_rx,
int slot_rx,
int *duration_rx_to_tx,
int *timing_advance,
int *ntn_koffset)
@@ -916,22 +917,43 @@ static inline void apply_ntn_config(PHY_VARS_NR_UE *UE,
if (UE->ntn_config_message->update) {
UE->ntn_config_message->update = false;
double total_ta_ms = UE->ntn_config_message->ntn_config_params.ntn_total_time_advance_ms;
UE->timing_advance = fp->samples_per_subframe * total_ta_ms;
const int mu = fp->numerology_index;
const int koffset = UE->ntn_config_message->ntn_config_params.cell_specific_k_offset;
int mu = fp->numerology_index;
int koffset = UE->ntn_config_message->ntn_config_params.cell_specific_k_offset;
if (*ntn_koffset != koffset) {
*duration_rx_to_tx = NR_UE_CAPABILITY_SLOT_RX_TO_TX + (koffset << mu);
*timing_advance += fp->get_samples_slot_timestamp(slot_nr, fp, (koffset - *ntn_koffset) << mu);
*ntn_koffset = koffset;
}
*duration_rx_to_tx = NR_UE_CAPABILITY_SLOT_RX_TO_TX + (koffset << mu);
if (koffset > *ntn_koffset)
*timing_advance += fp->get_samples_slot_timestamp(slot_rx, fp, (koffset - *ntn_koffset) << mu);
else if (koffset < *ntn_koffset)
*timing_advance -= fp->get_samples_slot_timestamp(slot_rx, fp, (*ntn_koffset - koffset) << mu);
*ntn_koffset = koffset;
const int abs_subframe_tx = 10 * frame_rx + ((slot_rx + *duration_rx_to_tx) >> mu);
const int abs_subframe_epoch =
10 * UE->ntn_config_message->ntn_config_params.epoch_sfn + UE->ntn_config_message->ntn_config_params.epoch_subframe;
int ms_since_epoch = abs_subframe_tx - abs_subframe_epoch;
// cope with sfn wrap-around
// this currently limits us to epoch times that are not more than 5.12 seconds in the future (allowed are up to 10.24 seconds)
// and ntn-UlSyncValidityDuration < 5.12 seconds (allowed are up to 900 seconds)
// TODO: fix this limitation by introducing the hyper frame number HFN
if (ms_since_epoch < -5120)
ms_since_epoch += 10240;
else if (ms_since_epoch > 5120)
ms_since_epoch -= 10240;
const double total_ta_ms = UE->ntn_config_message->ntn_config_params.ntn_total_time_advance_ms;
const double total_ta_drift = UE->ntn_config_message->ntn_config_params.ntn_total_time_advance_drift; // µs/s
const double total_ta_drift_variant = UE->ntn_config_message->ntn_config_params.ntn_total_time_advance_drift_variant; // µs/s²
UE->timing_advance = fp->samples_per_subframe * (total_ta_ms + (total_ta_drift / 1000.0) * (ms_since_epoch / 1000.0) + (total_ta_drift_variant / 1000.0) * (ms_since_epoch / 1000.0) * (ms_since_epoch / 1000.0));
LOG_I(PHY,
"k_offset = %d ms (%d slots), ntn_total_time_advance_ms = %f ms (%d samples)\n",
"k_offset = %d ms (%d slots), total_ta_ms = %f ms, total_ta_drift = %f µs/s, total_ta_drift_variant = %f µs/s², ms_since_epoch = %d ms, computed "
"timing_advance = %d samples\n",
*ntn_koffset,
*ntn_koffset << mu,
total_ta_ms,
total_ta_drift,
total_ta_drift_variant,
ms_since_epoch,
UE->timing_advance);
}
}
@@ -1088,9 +1110,6 @@ void *UE_thread(void *arg)
UE->max_pos_acc = 0;
shiftForNextFrame = -(UE->init_sync_frame + trashed_frames + 2) * UE->max_pos_acc * get_nrUE_params()->time_sync_I; // compensate for the time drift that happened during initial sync
LOG_D(PHY, "max_pos_acc = %d, shiftForNextFrame = %d\n", UE->max_pos_acc, shiftForNextFrame);
// TODO: remove this autonomous TA and use up-to-date values of ta-Common, ta-CommonDrift and ta-CommonDriftVariant from received SIB19 instead
if (get_nrUE_params()->autonomous_ta)
UE->timing_advance -= 2 * shiftForNextFrame;
// read in first symbol
AssertFatal(fp->ofdm_symbol_size + fp->nb_prefix_samples0
== UE->rfdevice.trx_read_func(&UE->rfdevice,
@@ -1215,8 +1234,8 @@ void *UE_thread(void *arg)
UE->N_TA_offset = new_N_TA_offset;
}
if (curMsg.proc.nr_slot_tx == 0)
nr_ue_rrc_timer_trigger(UE->Mod_id, curMsg.proc.frame_tx, curMsg.proc.gNB_id);
if (curMsg.proc.nr_slot_rx == 0)
nr_ue_rrc_timer_trigger(UE->Mod_id, curMsg.proc.frame_rx, curMsg.proc.gNB_id);
// RX slot processing. We launch and forget.
notifiedFIFO_elt_t *newRx = newNotifiedFIFO_elt(sizeof(nr_rxtx_thread_data_t), curMsg.proc.nr_slot_tx, NULL, UE_dl_processing);
@@ -1232,7 +1251,7 @@ void *UE_thread(void *arg)
}
// apply new NTN timing information
apply_ntn_config(UE, fp, slot_nr, &duration_rx_to_tx, &timing_advance, &ntn_koffset);
apply_ntn_config(UE, fp, curMsg.proc.frame_rx, curMsg.proc.nr_slot_rx, &duration_rx_to_tx, &timing_advance, &ntn_koffset);
// Start TX slot processing here. It runs in parallel with RX slot processing
// in current code, DURATION_RX_TO_TX constant is the limit to get UL data to encode from a RX slot
executables/position_interface.h
+6 -6
View File
@@ -41,16 +41,16 @@
/*----------------------------------------------------------------------------------------------------------------------------------------------------*/
// clang-format off
#define POSITION_CONFIG_PARAMS_DEF { \
{CONFIG_STRING_POSITION_X, HELP_STRING_POSITION, 0, .dblptr=&(position->positionX), .defuintval=0, TYPE_DOUBLE, 0}, \
{CONFIG_STRING_POSITION_Y, HELP_STRING_POSITION, 0, .dblptr=&(position->positionY), .defuintval=0, TYPE_DOUBLE, 0}, \
{CONFIG_STRING_POSITION_Z, HELP_STRING_POSITION, 0, .dblptr=&(position->positionZ), .defuintval=0, TYPE_DOUBLE, 0} \
{CONFIG_STRING_POSITION_X, HELP_STRING_POSITION, 0, .dblptr=&(position->X), .defuintval=0, TYPE_DOUBLE, 0}, \
{CONFIG_STRING_POSITION_Y, HELP_STRING_POSITION, 0, .dblptr=&(position->Y), .defuintval=0, TYPE_DOUBLE, 0}, \
{CONFIG_STRING_POSITION_Z, HELP_STRING_POSITION, 0, .dblptr=&(position->Z), .defuintval=0, TYPE_DOUBLE, 0} \
}
// clang-format on
typedef struct position {
double positionX;
double positionY;
double positionZ;
double X;
double Y;
double Z;
} position_t;
void get_position_coordinates(int Mod_id, position_t *position);