A test bench for a VLP system using CDMA as Multiple Access Technology

In this paper, we present a test bench for a Visible Light Positioning (VLP) system using Code Division Multiple Access (CDMA). A VLP system should be easy and low cost to install in existing infrastructures meaning there is no backbone network between the LEDs. CDMA can therefore be used as multiple access technology, with the challenging observation that the LEDs are transmitting data in a non-synchronized way to the receiver. Because the VLP system uses the received optical power for the positioning algorithm, Multiple Access Interference (MAI) can introduce errors. For the evaluation of the influence of MAI a test bench was developed where different CDMA codes are used in a VLP system. From practical measurements it is demonstrated that our approach leads to position errors smaller than 20 cm, making the system suitable for indoor Location Based Services (LBS).

[1]  Masao Nakagawa,et al.  Adaptive equalization system for visible light wireless communication utilizing multiple white LED lighting equipment , 2009, IEEE Transactions on Wireless Communications.

[2]  Zabih Ghassemlooy,et al.  Experimental demonstration of an indoor visible light communication positioning system using dual-tone multi-frequency technique , 2014, 2014 3rd International Workshop in Optical Wireless Communications (IWOW).

[3]  Guobin Shen,et al.  Epsilon: A Visible Light Based Positioning System , 2014, NSDI.

[4]  Jing Liu,et al.  Survey of Wireless Indoor Positioning Techniques and Systems , 2007, IEEE Transactions on Systems, Man, and Cybernetics, Part C (Applications and Reviews).

[5]  Hend Suliman Al-Khalifa,et al.  Comparative Survey of Indoor Positioning Technologies, Techniques, and Algorithms , 2014, 2014 International Conference on Cyberworlds.

[6]  Bart Nauwelaers,et al.  Optical CDMA codes for an indoor localization system using VLC , 2014, 2014 3rd International Workshop in Optical Wireless Communications (IWOW).

[7]  Sang-Kook Han,et al.  An Indoor Visible Light Communication Positioning System Using a RF Carrier Allocation Technique , 2013, Journal of Lightwave Technology.