Multi-user visible light communication and positioning system based on dual-domain multiplexing scheme

Abstract

Visible light communication and positioning (VLCP) is a promising candidate for constructing a multi-functional wireless network with large-scale connectivity and centimeter-level positioning. However, there is still a lack of effective methods to offer simultaneous visible light communication (VLC) and visible light positioning (VLP) functions for multiple users. Thus, we propose a multi-user VLCP system based on a dual-domain multiplexing (DDM) scheme, where both the time and code resources are multiplexed to transmit VLCP signals for multiple users simultaneously. In the proposed system, the data of different users are distinguished by using code division multiplexing technology, while the VLCP signals transmitted from different LEDs are separated by adopting time division multiplexing technology. The performances, including bit-error rate and positioning error, are evaluated through both simulation and experimentation to verify the feasibility of the proposed multi-user VLCP system. In the experiment, a VLCP system with four LED transmitters was able to simultaneously support low-speed VLC with free error and accurate VLP with a 2 cm precision for eight users. This offers an effective solution to support a large number of users with simultaneous VLC and VLP functions in the future multi-functional wireless network.