A PSO-Based Power Allocation Strategy for D2D and MS-NOMA Signals in Positioning-Timing-Communication Integration System

The Global Navigation Satellite System (GNSS) plays a crucial role in providing Positioning, Navigation, and Timing (PNT) services, but its signal is easily blocked indoors, which cannot meet the demand for high-precision positioning and timing in indoor scenarios. To address this issue, we proposed the Multi-Scale Non-Orthogonal Multiple Access (MS-NOMA) integrated signal, which can achieve sub-meter positioning accuracy and nan-meter level time synchronization accuracy while ensuring the Quality of Service (QoS) requirement and power budget of communication system. But the existing study did not consider the mutual interference between Device-to-Device (D2D) and MS-NOMA signals. Our major contributions are: Firstly, we derive the communication performance of cellular communication users (C-Users), the communication performance of D2D users (D-Users) and the ranging performance of positioning users (P-Users) based on the D2D signals multiplexing MS-NOMA signals uplink scenario. Secondly, we model a power allocation problem that considers QoS requirement and power constraints. Then, we propose a Particle Swarm Optimization-Based (PSO-Based) Power Allocation (PSOBPA) strategy which allocates the signal power of the C-Users in the MS-NOMA signal system and the signal power of D-Users. The numerical results show that our proposed PSOBPA strategy can improve the total system throughput by approximately 15% and the average ranging accuracy by around 4% compared to the average power allocation algorithm with the same bandwidth.