Remove unused function arguments
Some of them, because there are hundreds if not thousands. Warnings at compilation time can be enabled using -Wunused-parameter.
UE: Fix if target cell during handover has SSB at a different offset as in source cell
These changes fixed these observed issues:
- If target cell has a different SSB position compared to source cell during
ho - sync was not successful.
- RAR does not get decoded if SSB position has changed on the target cell
compared to source cell.
Actual problem is that SYNC does not happen on the target cell as frame parameters is not updated
and ssb start carrier is not correct in the UE frame parameters
function nr_get_ssb_start_sc to determine ssb_start_subcarrier
Remove L1 dependence from NR band number
L1 band information relied on get_band function that couldn't provide an
unambiguous result. Also there is no SCF compliant parameter for L1 and
generally we don't really need that information in L1.
The MR also remove a RU section that used nr_band but was never really
accessed in NR.
When writing dummy data or reading to trash, we don't need to allocate data buffers for each antenna.
We can allocate just for one antenna and use this buffer for each antenna.
These logs are very helpful to identify cell configuration
changes in MAC/PHY, for monitoring purposes, and to rapidly
signal integrity failures during re-establishment.
Make sure to apply Doppler and TA not directly when receiving the target cell ntn_config,
but apply Doppler just before the initial sync, and the TA after the initial sync when
we have tha actuel cell frame and slot numbers.
We need the ntn_config when reconfiguring the PHY layer for a new initial sync,
e.g. for calculating the DL Doppler frequency.
As a dedicated scheduled_response dl_config PDU it reaches the PHY layer too late,
as part of the phy_config.config_req it reaches the PHY layer in time with the
other configuration values.
Add symbol timing functions for NR_DL_FRAME_PARMS + optimization for slot timing
counterparts
Add two new functions for calculation symbol timestamp and symbol duration for
NR_DL_FRAME_PARMS. Also includes an optimization focused on removing
inefficiencies related slot-related counterparts.
1. Removed function pointers for functions get_samples_per_slot(),
get_samples_slot_timestamp() and get_slot_from_timestamp() as it does
not offer any advantage. The functions are now called directly from
everywhere.
2. Optimized these functions by removing loops where ever possible.
Separate timing_advance (N_TA) from timing_advance_ntn (N_common_TA_adj + N_UE_TA_adj)
to keep N_TA when updating N_common_TA_adj + N_UE_TA_adj.
Fixes#981
Instead of trying to estimate N_UE_TA_adj with a second degree polynomial,
we introduce orbit propagation to calculate N_UE_TA_adj with higher accuracy.
When we receive the satellite ephemeris data consisting of the satellite position vector
and the satellite velocity vector, we calculate parameters for orbit propagation, assuming
a circular orbit in the plane created by the satellite position vector and the satellite
velocity vector. This is done in the function prepare_ue_sat_ta().
Every millisecond, we use these parameters together with the time since epoch to calculate
the satellite position on that orbit and from this the reound-trip-time between UE and the
satellite, what corresponds to N_UE_TA_adj. This is done in the function apply_ntn_timing_advance().
- Replaced ITTI message queues with notifiedFIFO for RRC to MAC communication in UE.
- Enables correct message delivery to multiple MAC instances running in parallel threads.
- Introduced `nr_mac_rrc_message_t` union for MAC-RRC messages.
- Updated all relevant message handling and initialization code to use notifiedFIFO.
- Use MAX_NUM_NR_UE_INST in NR UE MAC to control number of MAC instances.
- Modify the MAC interface slightly so that nr_l2_init_ue only initializes one instance
Use MAX_NUM_NR_UE_INST for number of NR UE RRC instances. Change the RRC
interface slightly so nr_rrc_init_ue initializes only one RRC instance pointed
to by the id given to the function
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.
The implementation is limited 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 90 seconds).
To fix this limitation, the hyper frame number HFN has to be introduced at the OAI UE!
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 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.
During reestablishment the UE goes back to not synchronized state.
While the synchronizatin is running, we trash frames using the function readFrame().
And when we successfully synchronize, we skip samples to align with the start of the frame using syncInFrame().
In rfsimulator mode, both of these functions send dummy data using the function dummyWrite().
Unfortunately, the writeTimestamp provided to that function was always assuming a duration from RX to TX of NR_UE_CAPABILITY_SLOT_RX_TO_TX.
But in NTN mode, this value is changed when receiving SIB19.
Therefore we have to consider this changed value instead of the static one.
francescomani