Mobile User Connectivity in Relay-Assisted Visible Light Communications

Abstract

In this paper, we investigate relay-assisted visible light communications (VLC) where a mobile user acts as a relay and forwards data from a transmitter to the end mobile user. We analyse the utilization of the amplify-and-forward (AF) and decode-and-forward (DF) relaying schemes. The focus of the paper is on analysis of the behavior of the mobile user acting as a relay while considering a realistic locations of the receivers and transmitters on a standard mobile phone, more specifically with two photodetectors on both sides of a mobile phone and a transmitting LED array located upright. We also investigate dependency of the bit error rate (BER) performance on the azimuth and elevation angles of the mobile relay device within a typical office environment. We provide a new analytical description of BER for AF and DF-based relays in VLC. In addition we compare AF and DF-based systems and show that DF offers a marginal improvement in the coverage area with a BER < 10–3 and a data rate of 100 Mb/s. Numerical results also illustrate that relay-based systems offer a significant improvement in terms of the coverage compared to direct non-line of sight VLC links.

Combination of visible light and radio frequency bands for device-to-device communication

“…We assume N MTs randomly distributed within a square room with a dimension d (see Fig 1). As VLC is highly susceptible even to small changes in the angles between a transmitting MT (M T T ) and a receiving MT (M T R ) [18], we assume varying azimuthal orientation of both MTs. Note that the varying angles are more critical in terms of VLC channel quality than the MTs' mobility, since the mobility leads to a continuous and slow changes of the angles between the M T T and the M T R .…”

Noise Resilient Outdoor Traffic Light Visible Light Communications System Based on Logarithmic Transimpedance Circuit: Experimental Demonstration of a 50 m Reliable Link in Direct Sun Exposure

“…Visible Light Communications (VLC) represent a new wireless communication technology which transforms a basic LED lighting device into an intelligent dual purpose tool used for lighting and communications simultaneously [1][2][3][4]. VLC is based on the solid-state lighting devices' fast switching ability, which enables them to be used in communication purposes as well.…”

Channel and Bit Adaptive Power Control Strategy for Uplink NOMA VLC Systems

“…With the rapid development of solid-state lighting technology, visible light communication based on light emitting diodes (LEDs) has attracted a lot of interest in research [1][2][3][4][5][6] due to its unique merits such as low cost, large bandwidth, high security, freedom from spectral licensing issue, easy implementation into existing infrastructure, etc. However, multiuser communication support for VLC systems has become a challenging topic due to the limited modulation bandwidth of the LEDs and thus, multiple access technologies have become an hot spot for research.…”