Indoor Positioning System Based on Single LED Using Symmetrical Optical Receiver

We propose a novel visible light positioning (VLP) system based on a single light emitting diode (LED) using the symmetrical receiver. In the proposed receiver, a horizontal photodetector (PD) is located at the center and four tilted PDs are located symmetrically around the center. Based on the received signal strength (RSS), the high accuracy two-dimensional (2-D) positioning can be easily achieved and the average error is 2.32 cm when the PDs' polar angles are 20 degrees. Moreover, the 3-D location can also be estimated if a reference point is provided and the average error of the 3-D positioning is 3.42 cm. The proposed VLP system avoids the inter-cell interference (ICI) caused by multiple transmitters and achieves the positioning regardless of LED's and PDs' characteristics, which can be easily applied in scenarios with limited LEDs.