- 标题
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- 实验方案
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Optical Filter Designs for Multi-Color Visible Light Communication
摘要： In visible light communication (VLC), using multiple colors is an efficient way to enhance data rate, leading to multi-color VLC (MC-VLC). However, the performance of MC-VLC is jeopardized by the spectral overlaps of different colors. Thin-film optical filters, as the key component of MC-VLC systems, are usually adopted to separate colors. The passband bandwidth (BW) and center wavelength (CWL) of optical filters are critical to mitigate the crosstalk among colors, and thus must be carefully designed. Moreover, due to the intrinsic wavelength shift of the CWL with the varying of the angle of incidence (AoI), it is challenging to support mobility for MC-VLC. In this paper, we consider a joint design of multiple optical filters for MC-VLC by properly selecting the BW and CWL of each filter. We first investigate the optical filter design for a fixed receiver location. Then, to support mobility, we propose two robust optical filter designs, namely statistically and worst-case robust designs, which do not rely on the exact receiver location. Efficient methods are developed to solve the corresponding design problems and obtain the optimized optical filters. Compared with the existing optical filters, the proposed optical filters exhibits much better performance in various scenarios.
关键词： robust design,optical filter,spectrum shift,Mobility,multi-color LED,visible light communication,spectral overlap
更新于2025-09-09 09:28:46
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Joint data transmission and dimming control optimization for MIMO-VLC systems with channel-adaptive spatial constellation design
摘要： In the field of indoor wireless communications, visible light communications (VLCs) have attracted great attention for synergistically providing both illumination and data transmission. Meanwhile, multiple-input multiple-output (MIMO) technique has been applied in VLC systems to boost data rate by utilizing spatial resources. However, different geometrical locations of transceivers provide distinct optical channels which may effect the performance of the conventional MIMO-VLC techniques severely. In this paper, we propose the channel-adaptive spatial constellation (CASC) design for the MIMO-VLC systems by fully taking advantage of the channel state information (CSI), where the optimal transmitted signal constellation can be constructed via maximizing the minimum Euclidean distance (MED) of the received signal constellation. Meanwhile, the practical lighting constraints are taken into consideration with the non-linearity characteristic of light-emitting diode (LED) and the dimming requirements to maintain a specific indoor illumination level. Finally, simulations results indicate that the proposed CASC design can achieve significant improvement of error performance compared with the conventional MIMO-VLC schemes.
关键词： channel-adaptive spatial constellation (CASC),dimming control,multiple-input multiple-output (MIMO),minimum Euclidean distance (MED),visible light communication (VLC)
更新于2025-09-09 09:28:46
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New Algorithms for Energy-Efficient VLC Networks with User-Centric Cell Formation
摘要： The ever-increasing demand in high data rate has pushed the attention of the researchers to utilize the unregulated visible light spectrum for communication. This paper proposes a joint access-point (AP) association and power allocation algorithms for energy-ef?ciency (EE) maximization in visible light communication (VLC) networks. Based on the user-centric (UC) design, we ?rst show that the cell formation and power allocation are interlinked problems and should be treated jointly. We start by proposing a new algorithm for users’ clustering and then associating all the APs to the clustered users based on a proposed metric. We then propose two algorithms that jointly allocate the power, under quality-of-service (QoS) constraints, and decide which APs must be prevented from participating in communication. The ?rst algorithm is designed to maximize the EE, while the other algorithm is designed to reduce the complexity of the ?rst algorithm with acceptable degradation in the EE. Different from the related literature that allocated the power with the worst case interference information, we propose an iterative algorithm that allocates the power based on exact interference information, which signi?cantly improves the EE. The numerical results demonstrate that the proposed algorithms signi?cantly improve the EE compared to the existing work.
关键词： power allocation,energy ef?ciency,Visible light communication,user clustering
更新于2025-09-09 09:28:46
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Chaos Synchronization in Visible Light Communications with Variable Delays Induced by Multipath Fading
摘要： Visible Light Communication (VLC) uses light-emitting diodes to provide wireless connectivity in public environments. Transmission security in this emerging channel is not trivial. Chaotic modulation techniques can provide encryption directly in the physical layer based on the random-alike evolution and strong synchronization prospect given by deterministic chaos. In secure chaotic inclusion or embedding methods, continuous-time chaos oscillator models need to be synchronized via a coupling carrier. Here we present a ?rst numerical simulation study for the impact of the variable delays induced by line-of-sight and non-line-of-sight multipath fading in complete chaotic synchronization. More precisely, we analyze a chaotic Colpitts oscillator that is simultaneously transmitting the carrier to several mobile receivers via nine spotlights. Such induced delays depend on both the receiver position and the carrier frequency, in?uencing the complete synchronization required in modulation via chaotic inclusion. Correlation values for several receiver positions and carrier frequencies are presented, examining the progressive emergence of the multipath effect and its impact on chaotic synchronization. We show that, for the chaotic oscillator and coupling applied in the de?ned room settings, complete chaotic synchronization can be achieved and that it is robust up to the tens of MHz region.
关键词： multipath channels,network security,chaotic communication,visible light communication,nonlinear systems,chaos synchronization
更新于2025-09-04 15:30:14
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Efficient Indoor Data Transmission with Full Dimming Control in Hybrid Visible Light / Infrared Communication Systems
摘要： We design a hybrid visible light (VL) and infrared (IR) data transmission scheme for indoor visible light communication (VLC) systems with multi-pulse position modulation (MPPM) dimming control. A low-power IR light-emitting diode (LED) is adopted to assist the VL downlink especially when the dimming level of VL is low. Both VL and IR orthogonal frequency division multiplexing (OFDM) signals are transmitted alternately during the “on” and “off” periods of MPPM dimming controlled pulses. In this way, MPPM “off” periods can be efficiently utilized to convey data information without affecting illumination level. This arrangement ensures reliable data transmission under all illumination conditions including dark scenario. Numerical results show that the additional IR link can always facilitate the use of low M-ary quadrature amplitude modulation (M-QAM) levels. The fluctuation of required M-QAM symbol rates caused by dimming control can also be mitigated. At low dimming levels, both the receiver sensitivity requirement for the VL link and the total required transmit power can be significantly alleviated while maintaining a constant data rate at BER < 10-3. Even with limited launching power, the proposed scheme can still extend dimming control range while achieving stable and reliable transmission quality effectively.
关键词： multi-pulse position modulation (MPPM),Visible light communication (VLC),infrared (IR) communication,dimming control,orthogonal frequency division multiplexing (OFDM),hybrid transmission
更新于2025-09-04 15:30:14
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A study of the impact of VLC on the quality of lighting and display – EPSRC
摘要： Dr Wasiu Popoola of the University of Edinburgh talks about his research into visible light communication and shares the results of his latest work examining the underutilised optical spectrum as a potential pathway to wirelessly connect devices. The research investigates the impacts of visible light communication (VLC) on the fundamental properties of energy efficiency, light quality and life expectancy of a light-emitting diode (LED) that is primarily designed for lighting or display. It aims to deliver the required approach for optimising VLC and safeguard the LED’s reliability, durability and emitted light quality.
关键词： light quality,LED,VLC,energy efficiency,visible light communication,life expectancy
更新于2025-09-04 15:30:14
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Review on Li-Fi: an advancement in wireless network communication with the application of solar power
摘要： Light Fidelity, commonly referred to as Li-Fi is a technology that was introduced by a German physicist called Herald Hass. This technology in its own uniqueness considers the use of light (Light Emitting Diode, LED to be specific) as its medium of delivering high speed communication that complies with standard IEEE 802.15.7 bidirectional communication standard. This optical means of communications is also known as visible light communication. It is safer when compared with Wi-Fi network. This paper will focus on Li-Fi applications, comparison with existing technologies like Wi-Fi and the inclusion of an alternative source of power i.e., solar power, as a means of effectively optimizing on the availability and accessibility of the benefits in places where erratic or total power outage is a common trend.
关键词： solar power,Visible Light Communication (VLC),Li-Fi,Wi-Fi
更新于2025-09-04 15:30:14
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[IEEE 2018 International Conference on Indoor Positioning and Indoor Navigation (IPIN) - Nantes (2018.9.24-2018.9.27)] 2018 International Conference on Indoor Positioning and Indoor Navigation (IPIN) - Indoor Positioning Using OFDM-Based Visible Light Communication System
摘要： Precise indoor positioning is essential to support emerging applications of location aware mobile computing. Current positioning techniques that use signals transmitted in the Gigahertz region of radio-frequency spectrum do not provide highly accurate position estimates due to multipath propagation of signals. This paper proposes a novel positioning system which uses the entities of visible light communication (VLC) system as anchors and tags. Our technique scales with the number of tags and the VLC network provides both positioning and communication capabilities. The anchor points transmit the OFDM-based VLC signals synchronously, and we estimate the time differences of arrival between anchor points and tags using positioning reference signals embedded into the air-interface of the VLC system. Simulation results show that positioning accuracy of 10 cm or better is possible for over 95% of users if the sampling clock offset is better that 10 ppm, clock jitter is below 1 ps, and a bit resolution of at least 16 bits is available.
关键词： multipath propagation,OFDM,TDOA,visible light communication,indoor positioning
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE 7th Global Conference on Consumer Electronics (GCCE) - Nara, Japan (2018.10.9-2018.10.12)] 2018 IEEE 7th Global Conference on Consumer Electronics (GCCE) - Design of Compact and Vibration Resistant Receiver for Visible Light Communication Using MEMS mirror
摘要： We propose a compact and vibration-resistant receiver for visible light communication (VLC) between vehicles, where the vibration of the vehicle becomes a barrier for reliable communication. To address this problem, we designed a VLC receiver with a micro mirror, an inertial measurement unit (IMU), and an image sensor. A fast-blinking light is scanned by micro mirror and captured by image sensor efficiently, and the micro mirror controlled by IMU cancels the effect of motion of the vehicle. The performance of the proposed receiver is evaluated in experiments. The obtained results suggest that the proposed receiver is suitable for vibration environment.
关键词： Image sensor,Visible light communication,MEMS scanner mirror
更新于2025-09-04 15:30:14
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[IEEE 2018 Pacific Neighborhood Consortium Annual Conference and Joint Meetings (PNC) - San Francisco, CA, USA (2018.10.27-2018.10.30)] 2018 Pacific Neighborhood Consortium Annual Conference and Joint Meetings (PNC) - Robot Indoor Navigation Using Visible Light Communication
摘要： This work developed a robot indoor navigation system using visible light communication (VLC) technique. The movement direction of the robot is followed by the movement control signal transmitted from each VLC LED Lamp. The route planning system calculates the path from the user's location and the destination and the selected points, and based on the user's setting is shortest distance or priority path. The system contains several VLC LED Lamps, a VLC robot, a smart phone with Robot control App, and a server.
关键词： Indoor Navigation,Visible light communication (VLC)
更新于2025-09-04 15:30:14