Refactor DLSCH scheduler
Refactor the DLSCH post processor similarly to what has been done in
!3521 with the goal of saving an additional iteration through all UEs,
hopefully making the DLSCH scheduler faster.
It further includes changes to make working with and debugging multi-UE
operation easier:
- add some measurements in L1 (for total TX/RX time)
- a new option MACRLCs.[0].stats_max_ue to limit the number of UEs in
the periodic output (default: 8, 0=disable)
- avoid stack overflow in the MAC
- fix the writing of stats to nrMAC_stats.log and nrL1_stats.log when
the written output reduces by truncating the files
- avoid to schedule retransmission with 0 RBs.
The gNB will stop the periodical logging of UEs in MAC Info level after
a configurable number of UEs have been printed, by default 8.
Set it to 17 in some CI tests to ensure we still get all UEs for the
time being, as the CI might depend on this.
Fixes and updates for UL scheduling, notably DSUUU
Fix a number of problems that stem from !3521, notably regarding Msg3
scheduling, retransmissions in "UL-heavy" TDD scenarios, and BSR
handling. Modify a CI test to run a UL-heavy TDD scenario, and add
documentation for UL-heavy TDD scenarios.
Improve MAC docs for MCS and docker for BuildKit usage
See commits for details. The first one is for fixing an omission in
!3281, the second to clarify docker build usage.
Closes: #973
Previous commits removed min_grant_mcs and instead introduced
dl/ul_min_mcs as a more generic replacement.
Fixes: 96b0cae63e ("Drop 'min_grant_mcs' configuration parameter ")
Fixes: 699afafc6f ("Add support for 'dl_min_mcs' and 'ul_min_mcs'
configuration parameters")
The aggregation level search order for PDCCH candidates is modified:
- the search starts from desired_agg_level_index, which is a value from 0 to 4
proportial to pdcch_cl_adjust.
- pdcch_cl_adjust is a value between 0 and 1 that indicates PDCCH channel quality
by averaging HARQ DTX rate. A value of 0 means perfect channel, a value o 1 means
impaired channel.
RSSI threshold for PUSCH & PUCCH power control
To prevent ADC railing or "clipping" when the received power is too
large, introduce RSSI threshold parameters for PUSCH and PUCCH, which
are now configured in units of 0.1 dB. Here is how you can configure and
use these thresholds:
1. Configuration:
- Set the pusch_RSSI_Threshold and pucch_RSSI_Threshold parameters in
your configuration file (e.g., gnb.conf) (MACRLC section).
- These parameters define the maximum acceptable RSSI values for
PUSCH and PUCCH, respectively. The unit is either dBm or dBFS,
depending on the RSSI reporting configuration.
2. Usage:
- The nr_limit_tpc function will automatically adjust the Transmit
Power Control (TPC) commands based on the configured RSSI
thresholds.
- If the RSSI exceeds the threshold, the TPC command will be limited
to prevent further increase in power, thereby avoiding ADC
clipping.
- Introduced new configuration parameters `pusch_RSSI_Threshold` and `pucch_RSSI_Threshold`
(MACRLC section)
- Added `nr_limit_tpc` function in `gNB_scheduler_primitives.c` to limit TPC based on RSSI
threshold.
- Integrated `nr_limit_tpc` in PUCCH and PUSCH power control
Example Configuration
puxch_RSSI_Threshold takes value between -1280 and 0 and is mapped to range -128.0 dBm/dBFS
to 0.0 dBm/dBFS in 0.1 dB increments. Unit depends on RSSI reporting config.
pucch_RSSI_Threshold = -500; # Set the PUSCH RSSI threshold to -50.0dBm/-50dBFS
pucch_RSSI_Threshold = -600; # Set the PUCCH RSSI threshold to -60.0dBm/-60dBFS
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