A Low-Complexity Placement Design of Pinching-Antenna Systems

Pinching-antenna systems have recently been proposed as a promising solution to improve the wireless environment, not only inheriting the reconfiguration capability but also offering a unique feature: establishing line-of-sight links to mitigate large-scale path loss. However, sophisticated optimization of the placement of pinching antennas has very high complexity, which is challenging for practical implementation. This paper proposes a low-complexity placement design and provides a closed-form expression for the placement of pinching antennas, to maximize the sum rate of multiple downlink users. Orthogonal multiple access (OMA) and non-orthogonal multiple access (NOMA) are both investigated when each user is served by a single pinching antenna and only the OMA case is studied when each user is served by multiple pinching antennas. Simulation results indicate that pinching-antenna systems outperform conventional fixed-antenna systems and are better for large service areas.