Zhiguo Ding

Power Minimization for Pinching-Antenna Systems: Flexible Hybrid NOMA Perspective

Pinching-antenna systems have emerged as a novel promising technology for sixth-generation networks, capable of enhancing spectral efficiency by dynamically creating radiation points and line-of-sight links along a dielectric waveguide. However, the power consumption of such reconfigurable systems remains a critical challenge. This paper investigates a novel flexible hybrid non-orthogonal multiple access (NOMA) strategy for a downlink pinching-antenna system, where the simple two-user scenario is considered for the preliminary analysis of the hybrid NOMA scheme. With the primary objective of minimizing the total transmit power consumption, we formulate the optimization problem that jointly evaluates users’ power allocations and the time-variant locations of the single pinching antenna. To address the coupling between the spatial and power domains, we first derive closed-form power allocation expressions for various channel gain conditions and rigorously establish the feasibility criteria for the hybrid NOMA transmission. Building on this theoretical analysis, a closed-form-assisted reduced-complexity searching algorithm is proposed to determine the optimal antenna locations during different time slots. Numerical results validate the accuracy of the derived closed-form expressions and demonstrate the feasibility of the proposed hybrid NOMA scheme, as well as its ability to achieve superior power-consumption performance compared with conventional benchmarks. Moreover, the results provide valuable analytical insights into the time-varying pinching-antenna positioning, and establish potential applications and a foundational benchmark for hybrid NOMA assisted pinching-antenna systems.

Robust IRS and SWIPT Assisted Full-Duplex NOMA for 6G Networks

Outage-Constrained Environment Division Multiple Access (EDMA) for Pinching-Antenna Systems

A multi-user PA-enabled EDMA framework that accounts for probabilistic line-of-sight blockages, random non-LoS (NLoS) scattering, and practical inwaveguide attenuation is investigated, which yields significant performance gains over both PA-enabled and conventional time division multiple access designs.

Rate Maximization and Outage Analysis for BackCom-Assisted Uplink Pinching-Antenna Systems in IoT

In this paper, we consider a backscatter communication (BackCom)-assisted uplink pinching-antenna system in Internet of Things (IoT), where a non-energy-constrained IoT device provides radio frequency signals to support multiple energy-constrained IoT devices, with multiple pinching antennas deployed on a waveguide. We formulate a joint optimization problem to select a energy-constrained device and simultaneously design its power reflection coefficient and pinching antenna locations. The objective is to maximize the achievable rate of the selected device, subject to the quality of service requirements of the non-energy-constrained device, minimum energy harvesting at energy-constrained devices, and collision-free constraints imposed on the pinching antennas. The problem is non-convex and analytically intricate, due to the strong interdependence among device selection, power reflection coefficients, and antenna positions. To overcome these challenges, we propose a block coordinate descent-based successive convex approximation algorithm that iteratively transforms the original non-convex problem into a series of convex subproblems that can be solved efficiently. Additionally, we analyze a special case with a single pinching antenna, deriving the optimal antenna location along with an approximate outage probability expression and the corresponding diversity order. Simulation results demonstrate that the proposed system achieves higher achievable rates, lower outage probability, and improved diversity gain compared to conventional uplink fixed-antenna systems.