Abstract
Visible Light Communication (VLC) systems are designed to provide illumination and data services simultaneously. To achieve this goal, LED lamps are usually deployed on the ceiling of the rooms, in order to maximize the chances of having Line-of-Sight (LoS) connectivity between the VLC transmitter and the random locations that the VLC receiver can take. In an early stage of adoption, where the cost of LED lighting fixtures incorporating VLC technology will be high to enable ultra-dense deployments, it is expected that only one VLC transmitter is placed per room. In this situation, the use of direct illumination may have serious problems to satisfy the illumination constraints and provide a homogeneous data rate coverage. Moreover, the use of a single powerful LED lamp per room may create discomfort glare effect to users and over-exposure problems in areas of the room at which the light beam is directed. In order to address these problems, this paper studies the data rate that VLC technology can achieve with indirect illumination. That is, when the LED lamp is pointing upwards, and the VLC user receives the optical signal that is reflected back from the ceiling. Obtained simulation results show that indirect illumination provides a more homogeneous data rate coverage when compared to the direct case, while simultaneously verifying the illumination constraints in most of the places that the VLC receiver may take in the room.
Highlights
Ubiquitous use of Light-Emitting Diodes (LEDs), originally deployed to provide illumination, paves the way for the adoption of the new communication paradigm that is known as Visible Light Communication (VLC)
The receiver lies on a desk of height hdesk = 0.85 [m] that takes random locations on the room, and collects the optical signal that is irradiated by the PC-LED lamp placed on the center of the room at variable height hlamp, pointing either downwards or upwards
Each PC-LED lamp has a total radiant power Pled = 56 [W], an aggregate Spectral Power Distribution (SPD) that is approximated by summing the SPD in (2)-(3) with the parameters listed in Table I, and a viewing angle θmax = 60 [deg]
Summary
Ubiquitous use of Light-Emitting Diodes (LEDs), originally deployed to provide illumination, paves the way for the adoption of the new communication paradigm that is known as Visible Light Communication (VLC). One of the main drawbacks of VLC systems is related to the Line-of-Sight (LoS) blockage that may happen when a moving obstacle is placed between the transmitter and receiver To address this problem, the authors of [6]–[8] proposed to use multiple transmission points to provide diversity in terms of LoS links, assuming that few LED lamps can be placed on the room ceiling to provide direct illumination towards the PDs that are placed beneath. Some experimental results over NLoS links were presented in [14] when using optical mirrors deployed in the room, or when covering the room floor with a special material that improves its mean spectral reflectance coefficient [15] Motivated by these facts, this paper studies the achievable data rate of a VLC system with indirect illumination, where the LED lamp is pointing upwards and the VLC user receives.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
