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[IEEE 2018 International Conference on Advanced Technologies for Communications (ATC) - Ho Chi Minh City, Vietnam (2018.10.18-2018.10.20)] 2018 International Conference on Advanced Technologies for Communications (ATC) - Demonstration of A Visible Light Receiver Using Rolling-Shutter Smartphone Camera
摘要： Visible Light Communication (VLC) which has a mass of applications is getting much attention in both academic field and industry. Specifically, light-to-camera (LTC) communications in which information is transmitted to user through visible light signals; whereas, rolling-shutter camera-based receivers are utilized to capture and decode transmitted signals. In this paper, we present a demonstration of LTC communications system which includes a pair of transmitter and receiver. We have used an Arduino Genuino board to implement VLC transmitters which can transmit the identification (ID) messages through light-emitting diodes (LEDs)-based front-ends. At the receiver, we have developed an Android application which utilizes the CMOS image sensor (CIS) of the smartphone camera to receive the light signals. Besides, some practical problems of our LTC prototype and their solutions are also introduced in this paper.
关键词： Optical Camera Communication,Light-to-Camera,Rolling Shutter,Visible Light Communications (VLC)
更新于2025-09-23 15:23:52
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[IEEE 2018 International Conference on Advanced Technologies for Communications (ATC) - Ho Chi Minh City, Vietnam (2018.10.18-2018.10.20)] 2018 International Conference on Advanced Technologies for Communications (ATC) - Keynote talk #2: Visible light communications for 5G-and-beyond wireless telecommunications networks
摘要： Artificial general lighting sources are currently evolving through the traditional fluorescent and incandescent sources to the modern energy saving light bulbs and now white light emitting diodes (LEDs). This trend has been spurred on through global awareness of the necessity for reducing the size of our carbon footprint. The introduction of solid state LED lighting has attracted the attention of communications engineer's worldwide, enabling the achievement of the dual functionality of room illumination whilst simultaneously transmitting wireless data via visible light communication (VLC), or Light Fidelity (LiFi), in optical spectrum regime. Although the existing wireless networks are primely dominated by radio-based technology, the emerging VLC will play increasingly important role in future wireless telecommunications landscape. It is anticipated that both spectrum regimes, radio and optical, will eventually contribute equally for the next network generation, especially in nanocell and picocell network structures. This talk will outline the growth of optical wireless communications including VLC, and present the challenges and roadmap of the technology for the future generation of wireless networks.
关键词： Visible Light Communications,Networks,LED,LiFi
更新于2025-09-23 15:23:52
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Constellation-Optimal Beamformers For Multiuser MISO Broadcast Visible Light Communications
摘要： In this paper, we design energy-efficient space constellations for multiuser multi-input single-output (MISO) visible light communication broadcast systems with channel state information (CSI) at the receiver in the three scenarios: 1) with CSI at the transmitter (CSIT), 2) with statistical CSIT and 3) without CSIT. By utilizing the cooperation of multiuser interference, optimal multidimensional additively uniquely decomposable constellation groups are designed to optimize the received worst-case performance metrics of all users subject to two commonly used power constraints, i.e., average and peak optical power constraints. The resulting optimal designs are proved to be pulse amplitude modulation with an optimal beamformer, which can be efficiently attained by numerical search for Scenarios 1 and 2 and be given in a closed-form for Scenario 3. One of the common significant advantages of these designs is fast demodulation of the sum signal from a noisy received signal, since these optimal designs result in an equivalent ideal scalar AWGN channel. Comprehensive computer simulations demonstrate that our designs significantly outperform traditional zero-forcing, minimum mean square error and time-division methods.
关键词： Additively uniquely decomposable constellation group,multi-input single-output,maximum likelihood detection,optimal multidimensional constellation,visible light communications,broadcast channels
更新于2025-09-23 15:23:52
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Layered Adaptive Collaborative Constellation for MIMO Visible Light Communication
摘要： In this paper, we propose a novel technique to effectively design a channel adaptive collaborative constellation called the layered adaptive collaborative constellation (LACC) for multiple-input multiple-output visible light communications. Recently, a channel-adaptive space-collaborative constellation (CASCC) that designs the constellation with the consideration of channel into the model to improve the receiver mobility and enhance the error performance. However, this scheme only considers into optimization four constellation points that form a diamond shape in the receiver space. Our proposed scheme effectively exploits the layered structure of collaborative constellation and overcomes the aforementioned drawbacks of CASCC. Furthermore, an improved low-complexity maximum likelihood (ML)-based detector is derived. Simulation results show that the LACC can achieve some performance gain, compared with previous constellation design schemes for different scenarios, especially really high-correlation channels and under imperfect channel state information. Moreover, the proposed detector drastically reduces computational complexity while maintaining the same performance as a traditional ML detector.
关键词： maximum likelihood (ML) detection,multiple-input multiple-output (MIMO),Visible light communications (VLC),space collaborative constellation
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE International Conference on Internet of Things and Intelligence System (IOTAIS) - BALI, Indonesia (2018.11.1-2018.11.3)] 2018 IEEE International Conference on Internet of Things and Intelligence System (IOTAIS) - Optical Internet of Things within 5G: Applications and Challenges
摘要： The fifth generation (5G) telecommunications standards are being developed to meet the growing demands for high-speed wireless networks (i.e., few tens of Gigabits per second). The 5G standard stems largely from an increasing number of users and plethora of different devices, collectively referred to as smart devices, connecting to a network as part of Internet-of-Things (IoT). A few potential technologies have emerged for 5G such as millimeter waves, massive multiple-input multiple-output, and small cell communications. Although these technologies would satisfy the requirements of 5G, there is a complementary alternative wireless technology of optical wireless communications (OWC), which is being considered. As part of OWC, visible light communications (VLC) and optical camera communications (OCC) are the most attractive options for 5G networks and beyond. VLC with huge frequency spectrum integrated with IoT can open up a wide range of indoor and outdoor applications as part of future smart environments. This paper provides an overview of the all-optical IoT (OIoT) focusing on VLC and OCC based potential applications and challenges as part of 5G standards.
关键词： light emitting diodes (LEDs),visible light communications (VLC),Internet of things (IoT),Optical wireless communications (OWC),optical camera communications (OCC)
更新于2025-09-23 15:22:29
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Design of PAM-DMT-based Hybrid Optical OFDM for Visible Light Communications
摘要： In this letter, a pulse-amplitude-modulated based hybrid optical orthogonal frequency division multiplexing (PHO-OFDM) scheme is proposed. We use the high order quadrature-amplitude-modulation to replace the one-dimensional pulse-amplitude-modulated on the even subcarriers for compensating the data capacity weakness of the conventional pulse amplitude modulated discrete multitone (PAM-DMT). The combined time-domain PHO-OFDM signal has a larger amplitude range than the original PAM-DMT but with a reduced peak-to-average power ratio (PAPR). Besides that, a flexible power allocation method is introduced to the proposed PHO-OFDM systems to fully exploit the whole dynamic range of LEDs. The simulation results show that, under the same average bit rate, the proposed PHO-OFDM scheme has a better bit error rate performance compared with the conventional PAM-DMT scheme, thus demonstrating its application potential in visible light communications.
关键词： visible light communications (VLC),pulse-amplitude-modulated discrete multitone (PAM-DMT),optical orthogonal frequency division multiplexing (O-OFDM)
更新于2025-09-23 15:22:29
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IEEE Access Special Section Editorial: Optical Wireless Technologies for 5G Communications and Beyond
摘要： Wide bandwidth and dense spatial reuse are of extreme importance for future wireless communication networks, including 5G and beyond. In particular, these properties are important to enable future wireless networks to cope with the explosive increase in the demand for high data-rate communications. Optical wireless communications (OWC) is a promising technology for achieving this goal due to the abundant reusable license-free optical spectrum. This potential of OWC attracted significant global attention both from communications and optoelectronics viewpoints, and continues to do so.
关键词： 5G,beam-steering,mixed FSO/fiber backhauling,OFDM,MIMO,Optical wireless communications,vehicle-to-vehicle communications,free-space optics,vehicle-to-infrastructure communications,network-layer aspects,visible-light communications
更新于2025-09-23 15:21:21
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Indoor Localization Using K-Pairwise Light Emitting Diode Image-Sensor-Based Visible Light Positioning
摘要： A great deal of research has been devoted to studying indoor localization schemes for the development of location-based services. This study investigated an indoor localization system, including subsystems of non-line-of-sight (NLOS) image-sensor-based visible light communications (IS-VLC) and the proposed ??-pairwise light emitting diode (LED) image-sensor-based visible light positioning (IS-VLP), in a unified lighting environment. A smartphone received multiple LED identifiers through the designed NLOS IS-VLC and successfully performed the proposed ??-pairwise LED IS-VLP with ?? = 3 to achieve localization, with maximum localization errors of 2.92 cm and 3.54 cm being obtained for ceiling heights of 100 cm and 150 cm, respectively.
关键词： visible light communications (VLC),Image-sensor-based visible light positioning (VLP),light emitting diode (LED)
更新于2025-09-23 15:21:21
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Li-Tect: 3D Monitoring and Shape Detection using Visible Light Sensors
摘要： In this paper, we propose Li-Tect, an algorithm to detect the shape of an object located in an indoor environment using low cost optical elements through sensing the environment's light. The algorithm analyzes, relying on the predictability of optical propagation paths, how much light is expected to propagate in the absence of obstructions caused by the presence of an object. Then, based on the received light when the object is in the room, the algorithm infers the shape of the object. In addition, the algorithm considers the reflected paths from surfaces in order to determine the object's estimated shape. We study five different scenarios characterized by different levels of complexity, room sizes and a range of reflection nodes. The algorithm is also tested in a real prototype where several experiments are carried out in two scenarios to demonstrate the capabilities of Li-Tect in two and three dimensional monitoring and shape detection cases. Finally, the results show that the shape and the detection of objects in the scenarios can be easily acquired with high accuracy, even if the number of transceivers is reduced.
关键词： Visible Light Sensors,Ray Tracing,Monitoring,Visible Light Communications,Shape Detection
更新于2025-09-23 15:21:21
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Indoor Visible Light Communications, Networking, and Applications
摘要： Light-emitting diodes (LEDs) are changing indoor wireless communications. Visible light communications (VLC) that use LEDs as transmitters is an emerging research area and has significant commercial potential. The light emitted from LEDs can simultaneously carry information and provide illumination. Due to the intrinsic characteristics of light, VLC is more secure, more power efficient, and can provide higher network data transmission rates than radio frequency (RF) communications. This paper describes state-of-the-art VLC systems including transmitters, receivers, and channel models. Modulation and networking algorithms for physical layer and cross-layer designs are discussed. These algorithms are designed considering practical constraints, such as the bandlimited channel, illumination requirements, and transmitted power limitations. Indoor localization algorithms are proposed, with a particular focus on fingerprinting. In addition, this paper introduces practical applications of VLC in many fields such as national defense, healthcare, robotics, and vehicle-to-vehicle communications. The paper concludes with a discussion of the challenges, opportunities, and future of VLC.
关键词： Visible light communications,modulation,optical wireless communications,visible light positioning,LEDs,networking
更新于2025-09-23 15:19:57