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Merge remote-tracking branch 'origin/ntn_leo_freq_comp' into integration_2025_w15 (!3355)

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NR UE: add support for continuous frequency offset compensation (in particular NTN LEO Doppler)

- move function add_noise() to file
  openair1/SIMULATION/TOOLS/phase_noise.c
- refactor (co)sinus calculation out of phase_noise() into get_sin_cos()
  in nr_common.c
- NR UE: continuously estimate the frequency offset using PBCH DMRS
- NR UE: add command line parameter --initial-fo to specify known
  initial frequency offset
- NR UE: add support for continuous DL frequency offset compensation
  --cont-fo-comp
- NR UE: add support for continuous UL frequency offset
  pre-compensation. Depending on the main source of frequency offset,
  pre-compensate the UL frequency offset (FO) accordingly. Therefore
  modify the flag --cont-fo-comp to accept an integer value, where
  * 1 specifies, that the main FO contribution comes from the accuracy of the local oscillator (LO)
  * 2 specifies, that the main FO contribution comes from Doppler shift
- NR UE: add PI controller to continuous frequency offset compensation
- rfsimulator: enable and correct NTN LEO doppler simulation
- use SIMD to speed up nr_fo_compensation()
- Extend NTN LEO example in RUNMODEM.md to include continuous Doppler
  compensation
- NR UE: in nr_adjust_synch_ue() extend the peak search to +/- cyclic
  prefix size, esp. for LEO NTN scenarios the timing drifts during
  initial sync, which is mostly compensated with
  --ntn-initial-time-drift. But there might be a residual time offset,
  and by extending the peak search window we make this more tolerant.
- NR UE: remove unused nr_slot_tx_offset, it is unused since commit
  f3e60a14
- NR UE: remove now unnecessary local variable
  update_ntn_system_information, directly use
  UE->ntn_config_message->update instead
This commit is contained in:
Robert Schmidt
2025-04-14 16:59:27 +02:00
parent cb175569eb 75b237fb90
commit 07f8158378
27 changed files with 678 additions and 168 deletions
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executables/nr-ue.c
+24 -20
View File
@@ -41,6 +41,7 @@
#include "instrumentation.h"
#include "common/utils/threadPool/notified_fifo.h"
#include "position_interface.h"
#include "nr_phy_common.h"
/*
* NR SLOT PROCESSING SEQUENCE
@@ -438,9 +439,13 @@ static void UE_synch(void *arg) {
((ret.rx_offset << 1) / fp->samples_per_subframe * fp->slots_per_subframe)
+ round((float)((ret.rx_offset << 1) % fp->samples_per_subframe) / fp->samples_per_slot0);
// rerun with new cell parameters and frequency-offset
// todo: the freq_offset computed on DL shall be scaled before being applied to UL
nr_rf_card_config_freq(cfg0, ul_carrier, dl_carrier, freq_offset);
if (get_nrUE_params()->cont_fo_comp) {
UE->freq_offset = freq_offset;
} else {
// rerun with new cell parameters and frequency-offset
nr_rf_card_config_freq(cfg0, ul_carrier, dl_carrier, freq_offset);
UE->rfdevice.trx_set_freq_func(&UE->rfdevice, cfg0);
}
if (get_nrUE_params()->agc) {
nr_ue_adjust_rx_gain(UE, cfg0, UE->adjust_rxgain);
@@ -454,7 +459,6 @@ static void UE_synch(void *arg) {
cfg0->rx_freq[0],
cfg0->tx_freq[0]);
UE->rfdevice.trx_set_freq_func(&UE->rfdevice, cfg0);
UE->is_synchronized = 1;
} else {
int gain_change = 0;
@@ -553,6 +557,15 @@ static void RU_write(nr_rxtx_thread_data_t *rxtxD, bool sl_tx_action)
writeBlockSize -= dummyBlockSize;
}
// pre-compensate UL frequency offset
if (flags != TX_BURST_INVALID && get_nrUE_params()->cont_fo_comp) {
double ul_freq_offset = -UE->freq_offset * ((double)fp->ul_CarrierFreq / (double)fp->dl_CarrierFreq);
if (get_nrUE_params()->cont_fo_comp == 2) // different from LO frequency error compensation, Doppler UL pre-compensation has to be negative
ul_freq_offset = -ul_freq_offset;
for (int i = 0; i < fp->nb_antennas_tx; i++)
nr_fo_compensation(ul_freq_offset, fp->samples_per_subframe, writeTimestamp, txp[i], writeBlockSize);
}
int tmp = openair0_write_reorder(&UE->rfdevice, writeTimestamp, txp, writeBlockSize, fp->nb_antennas_tx, flags);
AssertFatal(tmp == writeBlockSize, "");
}
@@ -868,13 +881,12 @@ 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,
bool *update_ntn_system_information,
int *duration_rx_to_tx,
int *timing_advance,
int *ntn_koffset)
{
if (*update_ntn_system_information) {
*update_ntn_system_information = false;
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;
@@ -920,6 +932,8 @@ void *UE_thread(void *arg)
if (usrp_tx_thread == 1)
UE->rfdevice.trx_write_init(&UE->rfdevice);
InitSinLUT();
notifiedFIFO_t nf;
initNotifiedFIFO(&nf);
@@ -954,13 +968,9 @@ void *UE_thread(void *arg)
double ntn_init_time_drift = get_nrUE_params()->ntn_init_time_drift;
int ntn_koffset = 0;
int duration_rx_to_tx = NR_UE_CAPABILITY_SLOT_RX_TO_TX;
int nr_slot_tx_offset = 0;
bool update_ntn_system_information = false;
while (!oai_exit) {
nr_slot_tx_offset = 0;
if (syncRunning) {
notifiedFIFO_elt_t *res = pollNotifiedFIFO(&nf);
@@ -1085,12 +1095,6 @@ void *UE_thread(void *arg)
absolute_slot++;
TracyCFrameMark;
if (UE->ntn_config_message->update) {
UE->ntn_config_message->update = false;
update_ntn_system_information = true;
nr_slot_tx_offset = UE->ntn_config_message->ntn_config_params.cell_specific_k_offset << fp->numerology_index;
}
int slot_nr = absolute_slot % nb_slot_frame;
nr_rxtx_thread_data_t curMsg = {0};
curMsg.UE=UE;
@@ -1180,8 +1184,8 @@ void *UE_thread(void *arg)
shiftForNextFrame = ret;
pushNotifiedFIFO(&UE->dl_actors[curMsg.proc.nr_slot_rx % NUM_DL_ACTORS].fifo, newRx);
// apply new duration next run to avoid thread dead lock
apply_ntn_config(UE, fp, slot_nr, &update_ntn_system_information, &duration_rx_to_tx, &timing_advance, &ntn_koffset);
// apply new NTN timing information
apply_ntn_config(UE, fp, slot_nr, &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
@@ -1192,7 +1196,7 @@ void *UE_thread(void *arg)
curMsgTx->writeBlockSize = writeBlockSize;
curMsgTx->proc.timestamp_tx = writeTimestamp;
curMsgTx->UE = UE;
curMsgTx->proc.nr_slot_tx_offset = nr_slot_tx_offset;
int slot = curMsgTx->proc.nr_slot_tx;
int slot_and_frame = slot + curMsgTx->proc.frame_tx * UE->frame_parms.slots_per_frame;
int next_tx_slot_and_frame = absolute_slot + duration_rx_to_tx + 1;