Design Of Visible Light Communication System Research Articles

Impact of Optical-to-Electrical Conversion on the Design of an End-to-End Learning RGB-LED-Based Visible Light Communication System

Visible Light Communication (VLC) is emerging as a promising technology to meet the demands of fifth-generation (5G) networks and the Internet of Things (IoT). This study introduces a novel RGB-LED-based VLC system design that leverages autoencoders, addressing the often overlooked impact of optical-to-electrical (O/E) conversion efficiency. Unlike traditional methods, our autoencoder-based system not only improves communication performance but also mitigates the negative effects of O/E conversion. Through comprehensive simulations, we show that the proposed autoencoder structure enhances system robustness, achieving superior performance compared to traditional VLC systems. By quantitatively assessing the impact of O/E conversion—a critical aspect previously overlooked in the literature—our work bridges a crucial gap in VLC research. This contribution not only advances the understanding of VLC systems but also provides a strong foundation for future enhancements in 5G and IoT connectivity.

ARM CORTEX-M3 MİKRODENETLEYİCİ KULLANIMI İLE ÇOK TAŞIYICILI GÖRÜNÜR IŞIK HABERLEŞME SİSTEMİ GELİŞTİRİLMESİ

With the development of technology, the constraints and the needs in the field of communication have increased. Especially, limited and licensed radio frequencies that can cause electromagnetic interference and health problems in the use of wireless communication make the visible light communication (VLC) technologies very important. In this study, an ARM based VLC system design has been realized to implement a unique product with the use of low-cost and commercial off-the-shelf electronic components. In this context, receiver and transmitter circuits are designed, printed circuit boards and appropriate enclosures have been produced, as a result, a system prototype has been created to use in interior applications with standard ceiling height. The design is also one of the few implementations in which orthogonal frequency division multiplexing (OFDM) modulation and digital signal processing applications are performed by using ARM based microcontroller. Consequently, the system communication is achieved at a data rate of 3.5 kbps from a distance 1.8 m to 3 m. Also the system communication is successfully performed from the center of the light source up to 85 cm distance on the direct side and up to an angle of 50° on the azimuth.

Intelligent Reflecting Surface-Aided Indoor Visible Light Communication Systems

This letter explores the use of intelligent reflecting surfaces (IRSs) to address the line-of-sight (LoS) blockage issue in an indoor visible light communication (VLC) system. This is done while considering practical user behaviors such as random receiver orientation and the presence of obstructions in the direct link between the transmitter and the receiver. Specifically, a system model for an IRS-aided VLC system is proposed and a rate maximization problem is considered to determine the optimal orientation of the IRS mirror array to establish robust non-LoS links. A low-complexity iterative solution based on the sine-cosine algorithm is proposed for this non-convex optimization problem. Simulation results are used to verify the effectiveness of the proposed IRS-aided VLC system design and optimization algorithm in overcoming the LoS blockage issue.

Bit Error Probability Performance of Binary Dimmable Visible Light Communication Systems

This paper evaluates the practically achievable best error performance obtained from a dimmable visible light communication (VLC) system that conveys information using binary modulations, such as on-off keying (OOK). As compared to previous studies that address the ideal performance of dimmable VLC systems only over reliable channels with arbitrarily small error probability, this paper presents the best achievable error probability of various configurations with the dimming targets, signal quality, and data rate. The numerical results establish the ultimate decoding error performance targeted for dimmable VLC systems and are expected to provide a practical guideline for the enhanced VLC system design.

Low Cost and Large Bandwidth Visible Light Communication System Design

Aiming at the problem of insufficient bandwidth of transmitter and receiver of low-cost visible light communication system, this article applies novel-equalization circuits to separately expand the bandwidth of LED and transimpedance amplifier circuit to 114MHz and 95.7MHz. In addition, signal-to-noise ratio and bit error rate of the system are also analyzed by a line of sight model and the feasibility of the designed system is confirmed.

Enabling Multiple Access in Visible Light Communication Using Liquid Crystal Displays: A Proof-of-Concept Study

The directionality of optical signals provides an opportunity for efficient space reuse of optical links in visible light communication (VLC). Space reuse in VLC can enable multiple-access communication from multiple light emitting transmitters. Traditional VLC system design using photo-receptors requires at least one receiving photodetector element for each light emitter, thus constraining VLC to always require a light-emitter to light-receptor element pair. In this paper, we propose, design and evaluate a novel architecture for VLC that can enable multiple-access reception using a photoreceptor receiver that uses only a single photodiode. The novel design includes a liquid-crystal-display (LCD) based shutter system that can be automated to control and enable selective reception of light beams from multiple transmitters. We evaluate the feasibility of multiple access on a single photodiode from two light emitting diode (LED) transmitters and the performance of the communication link using bit-error-rate (BER) and packet-error-rate (PER) metrics. Our experiment and trace based evaluation through proof-of-concept implementation reveals the feasibility of multiple LED reception on a single photodiode. We further evaluate the system in controlled mobile settings to verify the adaptability of the receiver when the LED transmitter changes position.

Channel modelling for indoor visible light communications.

Visible light communication (VLC) allows the dual use of light-emitting diodes (LEDs) for wireless communication purposes in addition to their primary purpose of illumination. As in any other communication system, realistic channel modelling is a key for VLC system design, analysis and testing. In this paper, we present a comprehensive survey of indoor VLC channel models. In order to set the background, we start with an overview of infrared (IR) channel modelling, which has received much attention in the past, and highlight the differences between visible and IR optical bands. In the light of these, we present a comparative discussion of existing VLC channel modelling studies and point out the relevant advantages and disadvantages. Then, we provide a detailed description of a site-specific channel modelling approach based on non-sequential ray tracing that precisely captures the optical propagation characteristics of a given indoor environment. We further present channel models for representative deployment scenarios developed through this approach that were adopted by the Institute of Electrical and Electronics Engineering (IEEE) as reference channel models. Finally, we consider mobile VLC scenarios and investigate the effect of receiver location and rotation for a mobile indoor user. This article is part of the theme issue 'Optical wireless communication'.

Physical deployment of enhanced visible light communication system using forward error correction codes

SummaryWith the development of new generation lighting sources, visible light communication (VLC) system has become a complementary solution to traditional radio frequency wireless system. However, the error performance of VLC system is degraded because of multipath effects and interference from other lighting sources that, in turn, reduce the communication range. This work targets the issue of performance degradation of VLC systems in terms of communication range and demonstrates a VLC system design that utilizes forward error correction (FEC) codes as the main tool to fix this issue. Furthermore, the work also covers practical implementation of the proposed VLC system using UART modules programmed in MATLAB. The hardware results demonstrate that the communication range of the proposed VLC system is enhanced up to 0.5 m. Over and above, it is also shown through simulations that the coding gain of the proposed design is more when compared with existing VLC system(s).

Multi-cell VLC system design under illumination and communication constraints

Visible Light Communication (VLC) uses lamps light to convey information. As such, lamps in VLC systems work not only as illumination devices, but as VLC Access Points (VAPs) as well. This makes the choice of the lamps’ specifications and positions vital to satisfy the illumination and communication requirements. It is important that an indoor environment has the best possible VLC performance and the lowest possible power consumption while maintaining satisfactory illumination conditions. Designing multi-VAP systems is challenging due to the conflicting requirements of illumination and communication. For example, closely installed lamps give more consistent illumination but more inter-VAP interference, and vice versa. In this paper, we propose an optimal strategy to design multi-VAP systems. We consider the general design problem that aims to maximize the VLC performance while minimizing the total power consumption. This should be achieved while keeping satisfactory illumination conditions represented by the average illumination level and the degree of illumination consistency. The multi-VAP system design is formulated as a two objective design problem with constraints on illumination. The interplay between the system design parameters and the constraints and objectives is then studied. Finally, the algorithm to optimize multi-VAP design strategies is proposed.

Effect of Wiring and Cabling Topologies on the Performance of Distributed MIMO OFDM VLC Systems

Since most indoor spaces have multiple luminaires for illumination, for visible light communication (VLC) systems, multiple-input multiple-output (MIMO) communication emerges as a natural solution to improve the data rates and/or the link reliability. The existing works on MIMO VLC systems, however, overlook the characteristics of the lighting infrastructure and the luminaire design, which might have implications for the VLC system design. A luminaire typically consists of multiple LED chips. The wiring topology refers to how the LED chips are connected within the luminaire. The cabling topology, on the other hand, refers to how the luminaires are connected to the communication access point (AP). Based on the type and length of cabling and wiring, significant delays can be introduced, which should be taken into account in channel modeling. In this paper, we adopt the non-sequential ray tracing to model the distributed MIMO VLC channels for various practical wiring and cabling topologies. Based on the developed channel models, we provide a comparative performance analysis of repetition coding (RC), spatial multiplexing (SMUX), and spatial modulation (SMOD) MIMO modes. Our results quantify the effect of wiring/cabling delays and provide insights into the optimized design of lighting infrastructure and luminaires for the support of VLC as an add-on service.

IEEE 802.15.7r1 Reference Channel Models for Visible Light Communications

The IEEE has established the standardization group 802.15.7r1 “Short Range Optical Wireless Communications”, which is currently in the process of developing a standard for visible light communication (VLC). As with any other communication system, realistic channel models are of critical importance for VLC system design, performance evaluation, and testing. This article presents the reference channel models that were endorsed by the IEEE 802.15.7r1 Task Group for evaluation of VLC system proposals. These were developed for typical indoor environments, including home, office, and manufacturing cells. While highlighting the channel models, we further discuss physical layer techniques potentially considered for IEEE 802.15.7r1.

Optimization for link quality and power consumption of visible light communication system

Due to the complexity as well as trade-offs between objectives of the system, it is difficult to design a visible light communication (VLC) system with optimal link quality and power consumption. In this paper, the VLC system design problem is solved by using a multi-objective optimization method. Based on the results of the optimization process, we can determine the parameters to get a VLC system with optimal performance in respect of maximum link quality and minimum power consumption while illumination and other constraints are all satisfied.

LED Visible Light Communication System Design and Performance Optimization Based on Ethernet

To satisfy the requirements of visible light wireless communication technology, designed LED visible light communication application system based on Ethernet. Influence factors of system performance were studied and took specific measures to optimize system performance. Reduced the influence of background light, improved the communication distance, inhibited LED light source tailing phenomenon, and improved the rate of the edge of the LED. The LED visible light communication technology blends into the Ethernet, provides a new solution for wireless broadband access, this solution has the broad application prospect.