As part of this project, algorithm capable of decoding 5G NR in order to obtain the RF power of the full frequency and time resource grid was developed and implemented on Mathemetica. The algorithm mainly decodes the primary synchronization signal (PSS), secondary synchronization signal (SSS) and the physical broadcast channel (PBCH) signals present in a Synchronization Symbol Block (SSB). These signals are present in every radio frame and are of interest as they are independent of the ongoing traffic and can therefore be used to assess the RF exposure from the base stations. METAS measurement method uses for example SSS for this purpose (see METAS report " Technical report: Measurement Method for 5G NR Base Stations up to 6 GHz " dated 18 February 2020).
The developed algorithm can
- detect PSS, SSS and PBCH
- decode transmission bits
- obtain important information from PBCH
- retrieve the power of all resource elements in the resource grid
For example, in the case of a sample 5G NR downlink signal where a single user is present, the carrier frequency is 3.5 GHz, the numerology is 1 (Case B with 8 SSBs), channel bandwidth is 20 MHz and Cell ID is 3.