Joint Lambertian Model Calibration and Positioning of Photodiode Devices towards Integrated Optical Wireless Communication and Sensing

Visible light-based positioning (VLP) is indispensable for integrated sensing and communication in optical wireless networks. Conventional VLP methods require an accurate Lambertian emission model (LEM) with fixed parameters. However, this is hard to be met in practice due to inevitable measurement errors, and thus a small LEM error will lead to serious VLP performance loss. To solve this issue, a joint LEM calibration and positioning (JCAP) scheme is proposed. As the JCAP problem is non-convex in nature, a majorization minimization-based joint optimization method is developed to exploit hidden-convex substructures of the system model, thus yielding a tractable JCAP scheme. Moreover, the impact of system parameters (e.g., carrier frequency, initial LEM error and noise) on the VLP performance is revealed, which is useful for efficient VLP network development. It is verified by simulations that the proposed JCAP method outperforms the state-of-the-art VLP baselines due to our problem-specific joint LEM calibration mechanism design.