A Unified Approach for Pinching-Antenna-Assisted Non-Orthogonal Multiple Access With Integrated Sensing and Communication
Abstract
The novel flexible-antenna technology, referred to as pinching-antennas, has recently attracted significant academic interest. By embedding separate dielectric materials, these antennas can be activated at arbitrary points along waveguides, facilitating the flexible configuration of large-scale path loss. This paper conducts a performance analysis for a pinching-antenna-assisted uplink non-orthogonal multiple access (NOMA) system combined with integrated sensing and communication (ISAC). In particular, we focus on the case with a pinching-antenna and the sensing target in the same room, whereas the communication user is in another room. The sensing target and the communication user transmit simultaneously to a common pinching-antenna via line-of-sight (LoS) and non-LoS (NLoS) links, respectively, using uplink NOMA. Using a unified mean square error (MSE) framework, this work derives closed-form expressions for both sensing and communication outage probabilities, offering deeper insights into the joint reliability of uplink pinching-antenna-assisted NOMA-ISAC systems. This approach effectively bridges the gap between the information-theoretic and sensing-centric metrics, providing a comprehensive performance evaluation. The asymptotic expressions of the communication outage probability and sensing outage probability are also derived to gain useful insights, such as the diversity order. Monte Carlo simulations are performed to verify the analytical results. Numerical results reveal the superior performance of pinching-antenna-assisted NOMA-ISAC as compared to that of the pinching-antenna-assisted orthogonal multiple access (OMA) ISAC system. Furthermore, compared with a conventional antenna-assisted NOMA–ISAC benchmark, the proposed framework achieves significant sensing performance gain, while exhibiting a controllable sensing–communication trade-off. Finally, the impact of varying the pinching-antenna height, the room dimensions, imperfect successive interference cancellation (ipSIC), pathloss exponent, radar cross-section area and the MSE threshold on overall system performance is also examined.