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

Thomas Schlichterrequested to merge
ntn_leo_freq_comp into develop
  • 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

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