Results 21 to 30 of about 7,034 (308)

Optical wireless communication systems [PDF]

Optik, 2017
The emerging field of optical wireless communication (OWC) systems is seen as potential complementary technology to the radio frequency wireless communications in certain applications. It is deemed as a possible technology in the future 5th Generation communication networks to address the spectrum congestion and improve the system's capacity.
Ghassemlooy, Zabih, Zvanovec, Stanislav, Khalighi, Mohammad Ali, Popoola, Wasiu, Pérez, Joaquín, Khalighi, Mohammad-Ali   +5 more
openaire   +3 more sources

Preliminary Characterization of Coverage for Water-to-Air Visible Light Communication Through Wavy Water Surface

IEEE Photonics Journal, 2021
In this paper, we establish a water-to-air (W2A) visible light communication (VLC) link using green light emitting diode (LED), and investigate the coverage characteristics of the designed W2A-VLC link under calm and wavy water conditions.
Tianrui Lin, Nuo Huang, Chen Gong, Jianghua Luo, Zhengyuan Xu   +4 more
doaj   +1 more source

Optimal Transmission of VLC System in the Presence of LED Nonlinearity and APD Module Saturation

IEEE Photonics Journal, 2018
We address the optimal transmission of LED-based visible light communication (VLC) system using direct current biased optical orthogonal frequency division multiplexing (DCO-OFDM) modulation and avalanche photodiode (APD) receiver.
Meijun Gao, Chao Li, Zhengyuan Xu
doaj   +1 more source

Enhanced System Acquisition for NB-IoT

IEEE Access, 2017
Machine-type communication (MTC) is the key technology to support data transfer among devices (sensors and actuators) in Internet of Things (IoT).
Wenjie Yang, Min Hua, Jingjing Zhang, Tingting Xia, Jun Zou, Chengling Jiang, Mao Wang   +6 more
doaj   +1 more source

Multipath Extraction Based UL/DL Channel Estimation for FDD Massive MIMO-OFDM Systems

IEEE Access, 2021
In this paper, we propose a multipath extraction based uplink/downlink channel estimation scheme for wideband massive multiple-input multiple-output (MIMO) systems, where orthogonal frequency division multiplexing (OFDM) is adopted and the beam squint ...
Wei Ji, Feng Zhang, Ling Qiu
doaj   +1 more source

Multiuser Diversity Over Parallel and Hybrid FSO/RF Links and Its Performance Analysis

IEEE Photonics Journal, 2016
Hybrid free-space optical (FSO)/radio-frequency (RF) communication has emerged as an effective solution for high-data-rate wireless transmission. In this paper, multiuser diversity over parallel and hybrid FSO/RF links is discussed.
Li Chen, Weidong Wang, Chi Zhang
doaj   +1 more source

Optical wireless communications for micromachines

SPIE Proceedings, 2006
A key challenge for wireless sensor networks is minimizing the energy required for network nodes to communicate with each other, and this becomes acute for self-powered devices such as 'smart dust'. Optical communications is a potentially attractive solution for such devices.
O'Brien, D, Yuan, W, Liu, J, Faulkner, G, Elston, S, Collins, S, Parry-Jones, L   +6 more
openaire   +2 more sources

Measuring the Gap Between the Maximum Predictability and Prediction Accuracy of Human Mobility

IEEE Access, 2020
It has been claimed that human mobility is highly predictable and an upper bound of 93% predictability is achievable. However, there is a significant gap between the upper bound of predictability and the actual prediction accuracy in many data sets. This
Junyao Guo, Sihai Zhang, Jinkang Zhu, Rui Ni   +3 more
doaj   +1 more source

Digital Actuation Control of Soft Robotic Origami With Self‐Folding Liquid Crystal Elastomer Hinges

Advanced Functional Materials, EarlyView.
Self‐folding soft‐rigid hybrid robotic origami is enabled by liquid crystal elastomer actuators with embedded Joule heating and closed‐loop digital control. Digitally addressable hinges provide reversible and programmable transitions between distinct folded states while maintaining actuation performance at high cycle counts (over 1500).
David C. Bershadsky, Tuo Zhao, Glaucio H. Paulino, Emily C. Davidson   +3 more
wiley   +1 more source

Opportunities of Semiconducting Oxide Nanostructures as Advanced Luminescent Materials in Photonics

Advanced Materials, EarlyView.
The review discusses the challenges of wide and ultrawide bandgap semiconducting oxides as a suitable material platform for photonics. They offer great versatility in terms of tuning microstructure, native defects, doping, anisotropy, and micro‐ and nano‐structuring. The review focuses on their light emission, light‐confinement in optical cavities, and
Ana Cremades, Pedro Hidalgo, David Maestre, Ruth Martínez‐Casado, Emilio Nogales, Beatriz Rodríguez, G. Cristian Vásquez, Bianchi Méndez   +7 more
wiley   +1 more source