Merge remote-tracking branch 'origin/rssi-thres' into integration_2025_w02 (!3182)

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.

doc/MAC/mac-usage.md

@@ -197,6 +197,11 @@ In the `MACRLCs` section of the gNB/DU configuration file:
   beams, depending on hardware switching performance
 * `beams_per_period` (default 1): set of beams that can be simultaneously allocated in a
   period (`beam_duration`)
+* `pusch_RSSI_Threshold`: Value between -1280 and 0 which maps to range
+   from -128.0 dBm/dBFS to 0.0 dBm/dBFS. This limits PUSCH TPC commands in
+   case RSSI reaches the threshold and prevents ADC railing. Unit depends on
+   RSSI reporting config.
+* `pucch_RSSI_Threshold`: Same as above but for PUCCH
 
 In the `gNBs` section of the gNB/DU configuration file: some of the parameters
 affect RRC configuration (CellGroupConfig) of a UE, and are therefore listed