Field Verification of Wireless Cellular Communication-Based Subway Train Localization

Subways have become a preferred mode of transportation in metropolitan cities due to their punctuality, safety, and speed. The traditional methods of train localization, such as track circuit-based schemes, while effective, face challenges in precisely determining a train's location. In contrast, communication-based train control (CBTC) systems offer more precise localization but come with installation and maintenance costs. They also restrict access to train location data due to safety concerns. To address these challenges, We investigate wireless communication-based subway localization schemes, offering accurate localization without additional infrastructure. Most subway lines already have wireless communication networks, reducing costs. However, there have been limited studies on real-time subway train localization using these networks, especially in tunnels or underground where global navigation satellite systems (GNSS) is unavailable. We propose two innovative subway train localization algorithms based on wireless cellular communication systems, including a moving window-based scheme and a Kalman filter-based scheme. These algorithms were validated through a field test using long-term evolution technology, utilizing precise reference position data from the CBTC system. The results demonstrate the feasibility of wireless cellular communication-based subway train localization, particularly in environments where GNSS is unavailable, addressing the need for accuracy, cost-effectiveness, and accessibility in subway localization.