[Question] Does srsRAN use a method similar to OAI for PRACH channel noise calculation?

[Richard-yq]

Hi, I am working on PRACH noise calculation in different 5G implementations. In OpenAirInterface5G, PRACH channel noise is estimated using an Exponential Weighted Moving Average (EWMA) approach to smooth variations.
OAI approach:

      gNB->measurements.prach_I0 = ((gNB->measurements.prach_I0*900)>>10) + ((max_preamble_energy[0]*124)>>10); 
/*
  /// PRACH background noise level
  int prach_I0;
*/

I would like to know:

Does srsRAN implement a similar method for PRACH channel noise estimation?

If not, what algorithm does srsRAN use for this calculation?

If relevant, please point me to the corresponding source code files or functions where the calculation is performed.

Thanks for your help!

[dvdgrgrtt]

Hi @Richard-yq,
no, the srsRAN PRACH detector works on a preamble-by-preamble basis, without history. It's implemented here https://github.com/srsran/srsRAN_Project/blob/main/lib/phy/upper/channel_processors/prach_detector_generic_impl.cpp