5G NR UL SRS TDoA Positioning by OpenAirInterface

Utilizing cellular signals for User Equipment (UE) positioning becomes appealing where accurate positioning through global navigation satellite systems (GNSS), such as indoors, is impractical. The 5G New Radio (NR) standard, developed by 3GPP, has introduced advanced functionalities to facilitate the precise positioning of user terminals. In this work, we present a proof of concept for a 5G NR positioning system architecture based on OpenAirInterface (OAI) as well as a position estimation algorithm based on Particle Swarm Optimization (PSO) using UpLink Time Difference of Arrival (UL TDoA) of Sounding Reference Signal (SRS). TDoA is a widely used parameter for horizontal positioning that does not require synchronization between base stations and mobile stations. The simulation in this work is carried out on OAI RFsimulator. OAI is open-source software that includes UE and gNB implementations of 3GPP Release 16. The results from OAI RFsimulator validate the PSO position estimation accuracy of 1m

with the minimum required number of Line of Sight (LOS) gNBs where there is no GNSS link or prior information available.