Theoretical accuracy analysis of indoor visible light communication positioning system based on time-of-arrival

In this paper, an improved channel model and estimation for positioning in indoor environments using the visible light is presented. For positioning, the specific propagation and indoor channel model for visible light is used and a time-of-arrival (TOA) based distance estimations are proposed for two cases of known and unknown transmitter and receiver vertical distance. Based on this model and also assuming perfect synchronization between transmitter and receiver, the Cramer-Rao lower bound (CRLB) is computed as the theoretical limits on the performance and accuracy of any unbiased estimator. Unlike the radio frequency (RF) channel, the visible light communication (VLC) channel depends on the distance between the transmitter and receiver. Calculations show that proposed channel model and positioning result to more accurate distance estimate compared to their counterparts and the corresponding CRLB is almost 100 times lower than what was previously supposed.