5G Passive Positioning Based on Channel Decoding and Measurement

In the fifth-generation (5G) private network radio monitoring scenarios, it is essential to monitor and locate 5G terminals that serve as interference sources. The 5G mobile communication system offers excellent coverage and flexibility, making it highly promising for positioning applications. We propose a passive, non-cooperative positioning framework based on a deep understanding of the 5G protocol, capable of achieving two-dimensional positioning of target user equipment (UE) using at least two receivers. This paper proposes the Joint Channel Decoding and Measurement Positioning Method (JCDMP), which obtains observation values through multi-receiver channel measurements of Synchronization Signal Block (SSB) and Physical Random Access Channel (PRACH). Additionally, it mitigates spurious points by utilizing Timing Advance (TA) information obtained from Random Access Response (RAR) decoding. To mitigate positioning errors caused by the complex wireless channel environment, this paper introduces a two-step weighted least squares algorithm based on elliptic curves to enhance positioning accuracy. Simulation results demonstrate that, compared to existing passive positioning methods based on Time Difference of Arrival (TDOA), the proposed framework and algorithm deliver superior positioning performance.