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Merge remote-tracking branch 'origin/srs_phy_simulator' into integration_2026_w03 (!3718)

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Introduce SRS physical simulator and improvements

This MR consists of two parts:

- Introduces SRS physical simulator to test different configurations of
  SRS
- Improvements in the SRS channel estimation (Addressing the comments
  from old, unfinished MR !2875)
  - rewrite nr_srs_channel_estimation() to loop over rx antennas and
    antenna ports to be able to parallelize
  - Improvements in timing_advance_offset and timing_advance_offset_nsec
    computation
  - Introduce SRS multi-symbol channel estimation
    - The channel impulse response is estimated from the averaged
      channel frequency response over multiple symbols
    - The channel frequency estimates are left as they are to be able to
      estimate doppler in the future
  - Simplify SRS channel estimation to handle memory alignment in the
    case of different SRS configurations (eg: comboffset)

To use multiple symbols when running gNB, the following parameters needs
to be edited in the function get_srs_resource()

- srs_res->resourceMapping.startPosition with a range from {0,1,..,5}
  corresponds to the start symbol {13, 12, .. 8} with in a slot
- srs_res->resourceMapping.nrofSymbols indicates the number of symbols
  {n1, n2, and n4}

Make sure the that start symbol + number of symbols is < 14

The timing results for SRS in develop and srs_phy_simulator are as follows:

Command used: sudo ./nr_ulsim -n1000 -s50 -S50 -R273 -W2 -y2 -z2 -E 1 -P

develop

|__ RX SRS time                            124.94 us (1000 trials)		(124.94 total [ms])
    |__ Generate SRS sequence time           0.05 us (1000 trials)		(  0.05 total [ms])
    |__ Get SRS signal time                 19.41 us (1000 trials)		( 19.41 total [ms])
    |__ SRS channel estimation time         89.11 us (1000 trials)		( 89.11 total [ms])
    |__ SRS timing advance estimation time  13.10 us (1000 trials)		( 13.10 total [ms])
    |__ SRS report TLV build time            2.80 us (1000 trials)		(  2.80 total [ms])
        |__ SRS beam report build time       0.00 us (  0 trials)
        |__ SRS IQ matrix build time         2.73 us (1000 trials)

srs_phy_simulator

|__ RX SRS time                            211.93 us (1000 trials)		(211.93 total [ms])
    |__ Generate SRS sequence time           0.04 us (1000 trials)		(  0.04 total [ms])
    |__ Get SRS signal time                 19.55 us (1000 trials)		( 19.55 total [ms])
    |__ SRS channel estimation time        152.05 us (1000 trials)		(152.05 total [ms])
    |__ SRS timing advance estimation time  36.67 us (1000 trials)		( 36.67 total [ms])
    |__ SRS report TLV build time            2.96 us (1000 trials)		(  2.96 total [ms])
        |__ SRS beam report build time       0.00 us (  0 trials)
        |__ SRS IQ matrix build time         2.88 us (1000 trials)

Note that in srs_phy_simulator, to compute timing offset ns, an
oversampling factor of 2 is performed. Also, for peak detection, we
average the channel estimates for every port.
This commit is contained in:
Robert Schmidt
2026-01-13 13:39:32 +01:00
parent 0fdc095da5 5d545a6cc5
commit 93b3a5aedb
36 changed files with 1493 additions and 535 deletions
Download Patch File Download Diff File Expand all files Collapse all files
openair1/PHY/INIT/nr_init.c
+23 -20
View File
@@ -295,8 +295,8 @@ void nr_phy_config_request_sim(PHY_VARS_gNB *gNB,
{
NR_DL_FRAME_PARMS *fp = &gNB->frame_parms;
nfapi_nr_config_request_scf_t *gNB_config = &gNB->gNB_config;
//overwrite for new NR parameters
// overwrite with new NR parameters
uint64_t rev_burst=0;
for (int i=0; i<64; i++)
rev_burst |= (((position_in_burst>>(63-i))&0x01)<<i);
@@ -314,27 +314,30 @@ void nr_phy_config_request_sim(PHY_VARS_gNB *gNB,
gNB_config->carrier_config.num_tx_ant.value = fp->nb_antennas_tx;
gNB_config->carrier_config.num_rx_ant.value = fp->nb_antennas_rx;
gNB_config->tdd_table.tdd_period.value = 0;
//gNB_config->subframe_config.dl_cyclic_prefix_type.value = (fp->Ncp == NORMAL) ? NFAPI_CP_NORMAL : NFAPI_CP_EXTENDED;
if (mu==0) {
fp->dl_CarrierFreq = 2600000000;//from_nrarfcn(gNB_config->nfapi_config.rf_bands.rf_band[0],gNB_config->nfapi_config.nrarfcn.value);
fp->ul_CarrierFreq = 2600000000;//fp->dl_CarrierFreq - (get_uldl_offset(gNB_config->nfapi_config.rf_bands.rf_band[0])*100000);
fp->nr_band = 38;
// fp->threequarter_fs= 0;
} else if (mu==1) {
fp->dl_CarrierFreq = 3600000000;//from_nrarfcn(gNB_config->nfapi_config.rf_bands.rf_band[0],gNB_config->nfapi_config.nrarfcn.value);
fp->ul_CarrierFreq = 3600000000;//fp->dl_CarrierFreq - (get_uldl_offset(gNB_config->nfapi_config.rf_bands.rf_band[0])*100000);
fp->nr_band = 78;
// fp->threequarter_fs= 0;
} else if (mu==3) {
fp->dl_CarrierFreq = 27524520000;//from_nrarfcn(gNB_config->nfapi_config.rf_bands.rf_band[0],gNB_config->nfapi_config.nrarfcn.value);
fp->ul_CarrierFreq = 27524520000;//fp->dl_CarrierFreq - (get_uldl_offset(gNB_config->nfapi_config.rf_bands.rf_band[0])*100000);
fp->nr_band = 261;
// fp->threequarter_fs= 0;
switch (mu) {
case 0:
gNB->gNB_config.tdd_table.tdd_period.value = 7;
fp->dl_CarrierFreq = 2600000000;
fp->ul_CarrierFreq = 2600000000;
fp->nr_band = 38;
break;
case 1:
gNB->gNB_config.tdd_table.tdd_period.value = 6;
fp->dl_CarrierFreq = 3600000000;
fp->ul_CarrierFreq = 3600000000;
fp->nr_band = 78;
break;
case 3:
gNB->gNB_config.tdd_table.tdd_period.value = 3;
fp->dl_CarrierFreq = 27524520000;
fp->ul_CarrierFreq = 27524520000;
fp->nr_band = 261;
break;
default:
printf("unsupported numerology %d\n", mu);
exit(-1);
}
fp->threequarter_fs = 0;
frequency_range_t frequency_range = get_freq_range_from_band(fp->nr_band);
int bw_index = get_supported_band_index(mu, frequency_range, N_RB_DL);
gNB_config->carrier_config.dl_bandwidth.value = get_supported_bw_mhz(frequency_range, bw_index);