Pinching-Antenna System (PASS)-enabled Multicast Communications

TL;DR

PASS addresses multicast delivery over a single dielectric waveguide by using multiple movable PAs to create short-range LoS links that improve the worst-case SNR, defined as $overline_gamma = min_k gamma_k$. It formulates a non-convex optimization to maximize this worst-case metric by optimally placing the PAs, solved with a PSO-based algorithm and a distance-penalty term in the fitness. Numerical results show PASS can significantly outperform conventional fixed-multi-antenna transmission, especially at low PA counts, by enabling near-field energy focusing along the waveguide. The work suggests PASS as a practical, scalable multicast solution for 6G and beyond with reduced path loss and flexible deployment.

Abstract

Pinching-antenna system (PASS) is a novel flexible-antenna technology, which employs long-spread waveguides to convey signals with negligible path loss and pinching antennas (PAs) with adjustable positions to radiate signals from the waveguide into the free space. Therefore, short-distance and strong line-of-sight transmission can be established. In this paper, a novel PASS-enabled multicast communication framework is proposed, where multiple PAs on a single waveguide radiate the broadcast signals to multiple users. The multicast performance maximization problem is formulated to optimize the positions of all PAs. To address this non-convex problem, a particle swarm optimization-based algorithm is developed. Numerical results show that PASS can significantly outperform the conventional multiple-antenna transmission.

Figures (3)

• Figure 1: Illustration of PASS-enabled multicast communications.
• Figure 2: Multicast rate versus the area size, $L$.
• Figure 3: Normalized channel gain achieved by PASS over the area, where $M=2$ and $L=5$.