The Design of LED Array for Single Anchor-Based Visible Light Positioning

Visible light positioning (VLP) has garnered significant attention due to its high accuracy, low cost, and eco-friendliness. Among the various VLP methods, single-anchor-based localization using a light-emitting diode (LED) array shows great promise in challenging scenarios such as small rooms, corridors, and tunnels, yet it remains relatively underexplored. Consequently, this article primarily addresses the issues faced by the LED-array-based method and proposes the corresponding solutions. First, some work related to LED array design is discussed, such as the LED number determination, frequency assignment, array size, and layout design. From the array layouts examined, we evaluated six common configurations and selected the one that exhibits the optimal performance as the base array. Second, to cooperate with the LED array, a localization method joint the received signal strength (RSS) and the phase difference is proposed. Compared to traditional calibration-model-based methods, it significantly reduces the amount of calibration work. In addition, it fully utilizes the inter-LED relationship within the array to construct redundant observations. Subsequently, the genetic algorithm is used to further optimize the base array to improve its performance, where the optimization objective function is constructed by using the positioning performance index and constraints based on the relationship between the base array and its position. Finally, a series of analyses and simulations is conducted considering the time synchronization error and the receiver noise. The results indicate the feasibility and effectiveness of the proposed LED array and localization method, showcasing its suitability for numerous typical positioning scenarios.