Mobile Communications in Intelligent Rail Transit: From LCX to PASS

TL;DR

This paper introduces PASS, a flexible waveguide-based antenna system for rail communications, addressing limitations of LCX by enhancing capacity, reliability, and deployment adaptability in harsh transit environments.

Contribution

The paper presents PASS as a novel reconfigurable antenna architecture tailored for rail transit, with performance evaluation and a DL-based channel estimation framework.

Findings

PASS outperforms LCX in simulations for capacity and reliability.

PASS offers low deployment overhead and high flexibility for straight tracks.

Deep learning improves channel estimation under mobility conditions.

Abstract

Wireless communications in intelligent rail transit face harsh propagation conditions, including severe penetration loss, frequent blockages, and amplified large-scale fading. Existing leaky coaxial cables (LCX) provide wired-to-wireless conversion and stable coverage, but can be energy- and spectrum-inefficient, particularly at high carrier frequencies. Motivated by the growing demand for high-capacity and high-reliability rail services, this article introduces pinching-antenna systems (PASS), which are flexible waveguide-based architectures that enable reconfigurable radiation points with low deployment overhead and a natural fit to predominantly straight track geometries. We discuss the key benefits and deployment flexibility of PASS, evaluate their performance relative to LCX via representative simulations, and present a deep learning (DL)-enabled channel-estimation framework to cope with mobility-induced channel dynamics. Finally, we summarize the major open challenges for practical deployment and outline promising research directions.