A5022866169- Optical Wireless Communication Technologies
- Semiconductor Lasers and Optical Devices
- Advanced Photonic Communication Systems
- Optical Network Technologies
- Impact of Light on Environment and Health
- Indoor and Outdoor Localization Technologies
- Smart Parking Systems Research
- Advanced Memory and Neural Computing
- Neural Networks and Reservoir Computing
- Photoreceptor and optogenetics research
- Energy Harvesting in Wireless Networks
- Advanced Optical Network Technologies
- Advanced Optical Imaging Technologies
- Perovskite Materials and Applications
- Gaze Tracking and Assistive Technology
- solar cell performance optimization
- CCD and CMOS Imaging Sensors
- Photonic and Optical Devices
- Space Satellite Systems and Control
- IoT-based Smart Home Systems
- Radio Wave Propagation Studies
- Satellite Communication Systems
- Wireless Power Transfer Systems
- Advanced Fiber Optic Sensors
- Network Traffic and Congestion Control
University of Cambridge
2025
Northumbria University
2019-2024
University of Aveiro
2022
In optical camera communication (OCC) systems leverage on the use of commercial off-the-shelf image sensors to perceive spatial and temporal variation light intensity enable data transmission. However, transmission rate is mainly limited by exposure time frame camera. addition, camera's sampling will introduce intersymbol interference (ISI), which degrade system performance. this paper, an artificial neural network (ANN)-based equaliser with adaptive algorithm employed for first in field OCC...
The accuracy of the received signal strength-based visible light positioning (VLP) system in indoor applications is constrained by tilt angles transmitters (Txs) and receivers as well multipath reflections. In this paper, for first time, we show that tilting Tx can be beneficial VLP systems considering both line sight (LoS) non-line transmission paths. With Txs oriented towards center receiving plane (i.e., pointing F), power level maximized due to LoS components on F. We also proposed...
The increasing use of light emitting diodes in traffic lights offer excellent opportunities for implementation visible communications (VLC) based wireless technology as part intelligent transport systems smart environments. In this paper, we experimentally demonstrate vehicle to infrastructure (V2I) on the VLC using a real and camera over link span up 80 m. We show reduction modulation depth signal from 1000% 50% order track source when sending `0' symbols. Also presented is effect operating...
In this paper, we propose and validate an artificial neural network-based equalizer for the constant power 4-level pulse amplitude modulation in optical camera communications system. We introduce new terminology to measure quality of link terms number row pixels per symbol Npps, which allows a fair comparison considering progress made development current image sensors frame rates resolutions each frame. Using proposed equalizer, experimentally demonstrate non-flickering system using single...
Precision beam pointing plays a critical role in free-space optical communications terminals uplink, downlink and inter-satellite link scenarios. Among the various methods of steering, use fast steering mirrors (FSM) is widely adopted, with many commercial solutions employing diverse technologies, particularly focusing on small, high-bandwidth mirrors. This paper introduces method using lightweight, off-the-shelf components to construct custom closed-loop mirror platform, suitable for...
In this paper, we investigate the performance of a vehicular visible light communications (VVLC) link with non-collimated and incoherent source (a light-emitting diode) as transmitter (Tx), two different optical receiver (Rx) types camera photodiode (PD)) under atmospheric turbulence (AT) conditions aperture averaging (AA). First, present simulation results indicating improvements in signal-to-noise ratio (SNR) AT AA increasing size concentrator. Experimental investigations demonstrate...
Abstract This article investigates the use of a visible light positioning system in an indoor environment to provide three dimensional (3D) high‐accuracy solution. The proposed leveraged single light‐emitting diode and image sensor at transmitter receiver (Rx) respectively. can retrieve 3D coordinate Rx using combination angle arrival received signal strength (RSS). To mitigate error induced by lens Rx, novel method is experimentally tested. authors show that, outperforms previously reported...
This paper proposes a novel approach to provide privately secured multiple-input and multiple-output visible light communication (VLC) in the mobility conditions. In proposed system, private VLC link is adaptively allocated mobile user all time thanks movement tracking assistance by camera-based detection system. The generation of dynamic location-based scrambling matrix will be introduced providing zone within full normal coverage illumination area. An extensive range numerical evaluation...
The increasing proliferation of internet-connected devices and the widespread reliance on wireless communication in daily activities are limiting capabilities radio frequency (RF) spectrum to meet data traffic demands. rise connectivity requirements realize sixth generation (6G) networks, coupled with growth utilization artificial intelligence its associated transmission massive amounts data, contributing need leverage optical complement already congested RF bands. In general, encompasses a...
Recently, neuromorphic sensors, which convert analogue signals to spiking frequencies, have been reported for neurorobotics. In bio-inspired systems these sensors are connected the main neural unit perform post-processing of sensor data. The performance networks has been improved using optical synapses, offer parallel communications between distanced neural areas but sensitive intensity variations signal. For with several optically unit, use optical synapses is not an advantage. To...
Spiking neural networks (SNN) can control single-joint robotic arms' precise rotation and force when shape memory alloy (SMA) actuators are used. SNN receives feedback from neuromorphic sensors for controlling anthropomorphic fingers, which typically respond to the flexion angle applied fingertips. The fingers hands in relative motion with robot's body, includes main unit limb's control. An elegant method implement connection between on limbs is use visible light communication technology....
In this paper, we study the design aspects of an indoor visible light positioning (VLP) system that uses artificial neural network (ANN) for estimation by considering a multipath channel. Previous results usually rely on simplistic line sight model with limited validity. The considers influence noise as performance indicator comparison between different approaches. Three ANN algorithms are considered, including Levenberg-Marquardt, Bayesian regularization, and scaled conjugate gradient...
This paper provides experimental results for a multi-user visible light communications system using multi-band carrier-less amplitude and phase (m-CAP) modulation scheme. We optimize the performance by adapting pulse shaping filter parameters, subcarrier spacing allocating different baud rates to individual sub-bands called allocated m-CAP (Am-CAP). show that maximal data rate of ∼468 Mb/s four users can be supported while gaining higher flexibility optimization same or lower computational...
This paper presents an experimental investigation of a screen-to-camera-based communication (S2C) system. The study examines the performance smartphone transmitter (Tx) screen in terms power received, beam profile, and Lambertian order as well evaluates impact different transmission conditions such distance, tilt, rotation angles. results demonstrate that for line sight (LOS) link, Tx has average 3.5 accuracy over 100%. Overall, demonstrates potential optical camera technology development...
This paper describes a vehicle-to-vehicle (V2V) communication system, employing optical camera communications (OCC). The system comprises the light emitting diode (LED)-based taillights and raspberry used as transmitter (Tx) receiver (Rx), respectively. sectorized (i.e., Tx) are intensity modulated at different frequencies, convolutional neural network (CNN) Rx is for scene analysis, region of interest (RoI) selection, symbol detection. Results show that, data rates constrained by frame rate...
We report, for the first time in literature, an optical camera communications (OCC) link leveraging a near-infrared band at wavelength of 850 nm that is visible to standard and undetectable by human eye. An experimental test-bed developed evaluated proposed system. The quality communication measured terms eye diagram bit error rate (BER) different signal bandwidths. demonstrated that, acceptable BER (below forward correction limit) can be achieved with data ~2 kbps using single...
This paper addresses the effects of blocking and shadowing due to peoples' movement on performance visible light positioning system based received signal strength. We consider both line-of-sight non-line-of-sight paths using a non-sequential ray-tracing model, channel is characterised with without shadowing. A linear least square polynomial regression model proposed for position estimation. show that, VLP accuracy degrade by ~90 ~67% shadowing, respectively. Besides, at confidence interval...
In this work, a new indoor visible light positioning algorithm is proposed based on support vector machines (SVM) and polynomial regression. Two different multipath environments of an empty room furnished are considered. The starts by addressing the received power distance relation, considering regression models fitted to specific areas room. second stage, SVM used classify best-fitted polynomial, which with nonlinear least squares estimate position receiver. results show that, in room,...