Indoor visible light location algorithm based on virtual fingerprint database

A localization algorithm based on virtual fingerprint database is proposed in the indoor visible positioning system to solve the problem that the fingerprint positioning algorithm has low localization accuracy under the condition of low distribution density of reference nodes. In the fingerprint database establishment stage, the positioning area is divided into multiple small areas according to the distribution of the reference nodes, and several virtual reference nodes are inserted into each small area to set up a virtual fingerprint database by bilinear interpolation. In the positioning period, firstly find the area where target belongs to, then, the RSSI value is matched with the virtual fingerprint database of this small area, and the position coordinates are estimated by weighting algorithm. The simulation experiment results show that the average positioning error is reduced from 0.52m to 0.38m in the 7m × 7m positioning area compared with the unimproved fingerprint location method with the same distribution density of the reference nodes. The localization speed is affected by limited; it does not reduce the real-time performance of the algorithm.

I. Introduction

The demand for indoor location is increasing day by day in modern society. In large indoor spaces, including museums, commercial centers, airports; underground parking and so all require accurate location information. Since GPS signals are blocked by buildings and are not suitable for indoor environment, many indoor positioning schemes based on wireless communication technologies, such as Wi-Fi, radio frequency identification and UWB, have been proposed. As a new kind of wireless communication technology, visible light communication can transmit the user's location information through lighting facilities. The biggest advantage of indoor positioning system based on this technology is that it does not need to invest a large amount of positioning infrastructure, thus saving the cost of positioning system, which makes it popular in the field of indoor location.