Optimal signal design for visible light positioning under power and illumination constraints

Abstract

The optimal design of transmit signals for light-emitting diodes (LEDs) in a visible light positioning (VLP) system is analyzed with the objectives of im-provements in localization accuracy and power efficiency. Specifically, the lo-calization performance maximization problem is addressed for asynchronous and synchronous VLP systems where certain system limitations including power con-sumption, illumination, and effective bandwidth are considered, and the localiza-tion performance is quantified using the Cram´er-Rao lower bound (CRLB). The formulated signal design problems are demonstrated to be convex optimization problems and some properties of the optimal signal design parameters are found. On the other hand, the signal design problem is also formulated for achieving the lowest possible power consumption while guaranteeing a certain localization ac-curacy. Then, the optimal signal design parameters resulted from the solution of these optimization problems are used to construct the optimal transmit signals in the LEDs. The advantages of the optimal signal design approach is demonstrated through the numerical experiments while also presenting a comparison with the state-of-the-art optimal power allocation method in the literature.