Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

Multicasting Pinching Antenna Systems With LoS Blockage

Muhammad Fainan Hanif, Yuanwei Liu

TL;DR

The paper addresses blockage-aware downlink multicasting with pinching antennas (PASS) by formulating a nonconvex max-min SNR problem over PA positions along a waveguide under LoS blockage modeled by a Bernoulli-like factor. It develops a robust MM framework with a convex surrogate $L_u(\mathbf{x})$ and derives two practical coordinate-ascent solvers: Candidate Search Method (CSM) and Bisection Search Method (BSM). The MM iterations converge to a KKT point, with complexity analysis showing BSM typically dominates CSM in scalability. Numerical results demonstrate that PASS-based multicasting outperforms conventional antennas in non-LoS environments, and that BSM provides favorable computational efficiency for larger numbers of users and PAs. Overall, the work presents a blockage-aware, scalable approach for optimizing multicast performance in high-frequency PASS deployments.

Abstract

Pinching-antenna systems (PASS) represent a promising customizable wireless access mechanism in high-frequency bands, enabled by dielectric waveguides and movable dielectric particles, called pinching antennas (PAs). In this work, we study optimal position allocation of PAs in PASS for multicasting in the downlink when a line-of-sight (LoS) link does not necessarily exist between all users and the PAs. The multicasting problem is solved by leveraging minorization-maximization (MM) principle to yield a provably convergent algorithm. In each run of the MM based procedure, we solve a convex surrogate problem using two methods called the candidate search method (CSM) and the bisection search method (BSM). With both BSM and CSM, we not only report superior performance of the multicasting PASS in non-LoS environments compared to conventional antenna systems (CAS), but also determine that BSM yields better overall computational complexity when the number of users and PAs increases. For example, we report that when we have 8 PAs and 25 users, the execution time with the CSM is approximately 2.5 times that with the BSM.

Multicasting Pinching Antenna Systems With LoS Blockage

TL;DR

The paper addresses blockage-aware downlink multicasting with pinching antennas (PASS) by formulating a nonconvex max-min SNR problem over PA positions along a waveguide under LoS blockage modeled by a Bernoulli-like factor. It develops a robust MM framework with a convex surrogate and derives two practical coordinate-ascent solvers: Candidate Search Method (CSM) and Bisection Search Method (BSM). The MM iterations converge to a KKT point, with complexity analysis showing BSM typically dominates CSM in scalability. Numerical results demonstrate that PASS-based multicasting outperforms conventional antennas in non-LoS environments, and that BSM provides favorable computational efficiency for larger numbers of users and PAs. Overall, the work presents a blockage-aware, scalable approach for optimizing multicast performance in high-frequency PASS deployments.

Abstract

Pinching-antenna systems (PASS) represent a promising customizable wireless access mechanism in high-frequency bands, enabled by dielectric waveguides and movable dielectric particles, called pinching antennas (PAs). In this work, we study optimal position allocation of PAs in PASS for multicasting in the downlink when a line-of-sight (LoS) link does not necessarily exist between all users and the PAs. The multicasting problem is solved by leveraging minorization-maximization (MM) principle to yield a provably convergent algorithm. In each run of the MM based procedure, we solve a convex surrogate problem using two methods called the candidate search method (CSM) and the bisection search method (BSM). With both BSM and CSM, we not only report superior performance of the multicasting PASS in non-LoS environments compared to conventional antenna systems (CAS), but also determine that BSM yields better overall computational complexity when the number of users and PAs increases. For example, we report that when we have 8 PAs and 25 users, the execution time with the CSM is approximately 2.5 times that with the BSM.
Paper Structure (8 sections, 1 theorem, 20 equations, 4 figures, 3 algorithms)

This paper contains 8 sections, 1 theorem, 20 equations, 4 figures, 3 algorithms.

Table of Contents

  1. Introduction
  2. System Model and Problem Formulation
  3. Proposed Solution
  4. Candidate Search Method (CSM) for Maximization of Lower Envelope of Inverted Parabolas
  5. Bisection Search Method (BSM) for Coordinate Ascent
  6. MM Framework and Complexity Comparison
  7. Numerical Results
  8. Conclusion

Key Result

Theorem 1

The function $f_u(t)$ satisfies where $z_0$ is the given point and

Figures (4)

  • Figure 1: Pinching antenna multicast transmission in the presence of blocking objects.
  • Figure 2: Variation of the objective min. SNR with transmit power for different $\alpha$. We fix $U=5$ and $P=5$.
  • Figure 3: Convergence behaviour of Algorithm \ref{['alg:multicast_PA_blck']} for different $P_{\text{TX}}$. The parameters $\alpha=0.01,P=5$ and $U=5$ are fixed.
  • Figure 4: Variation of execution time of Algorithm \ref{['alg:multicast_PA_blck']} for different $U$. The parameters $U=5,P_{\text{TX}}=40$ dBm and $\alpha=0.01$ are fixed.

Theorems & Definitions (2)

  • Theorem 1
  • Remark 1