A Comprehensive Accuracy Analysis of Visible Light Positioning under Shot Noise

Visible light positioning (VLP) has received increasing attentions recently due to its high accuracy, low cost, long lifetime and so on. From the theoretical perspective, many works leverage the Cramer-Rao lower bounds (CRLBs) to investigate the limit of positioning accuracy in VLP system. However, most of them only consider the thermal noise in the signal model while ignore the shot noise, which is signal-dependent and is the dominant noise in some practical scenarios. In this paper, we derive the CRLB of the VLP system under the consideration of both the thermal noise and the shot noise. We reveal that shot noise will significantly affect positioning accuracy as received signal strength (RSS) grows. Numerical results further illustrate that the shot noise will significantly worsen the positioning accuracy of the VLP system, especially in the low signal-noise- ratio (SNR) and high RSS regime.