  In this paper, a received signal strength assisted Perspective-three-Point
positioning algorithm (R-P3P) is proposed for visible light positioning (VLP)
systems. The basic idea of R-P3P is to joint visual and strength information to
estimate the receiver position using 3 LEDs regardless of the LEDs'
orientations. R-P3P first utilizes visual information captured by the camera to
estimate the incidence angles of visible lights. Then, R-P3P calculates the
candidate distances between the LEDs and the receiver based on the law of
cosines and the Wu-Ritt's zero decomposition method. Based on the incidence
angles, the candidate distances and the physical characteristics of the LEDs,
R-P3P can select the exact distances from all the candidate distances. Finally,
the linear least square (LLS) method is employed to estimate the position of
the receiver. Due to the combination of visual and strength information of
visible light signals, R-P3P can achieve high accuracy using 3 LEDs regardless
of the LEDs' orientations. Simulation results show that R-P3P can achieve
positioning accuracy within 10 cm over 70% indoor area with low complexity
regardless of LEDs orientations.
