VLC-based indoor positioning algorithm combined with OFDM and particle filter

Visible light communications (VLC) have recently attracted a growing interest and can be a potential solution to realize indoor positioning, however, the performance of existing indoor positioning system is limited by multipath distortion inside a room. In order to combat the effect of multipath distortion, this paper proposes an LED-based indoor positioning algorithm combined with hybrid OFDM (HOFDM), in which asymmetrically clipped optical OFDM (ACO- OFDM) is transmitted on the odd subcarriers while using pulse amplitude modulated discrete multitone (PAM-DMT) to modulate the imaginary part of each even subcarrier. In this scheme, we take a combined approach where a received-signal-strength (RSS) technique is employed to determine the location of the receiver and realize the 3-D positioning by Trust-region-based positioning. Moreover, a particle filter is used to further improve the positioning accuracy. Results confirm that this proposed positioning algorithm can achieve high accuracy even with multipath distortion, and the algorithm has better performance when combined with particle filter.