"uuid","repository link","title","author","contributor","publication year","abstract","subject topic","language","publication type","publisher","isbn","issn","patent","patent status","bibliographic note","access restriction","embargo date","faculty","department","research group","programme","project","coordinates"
"uuid:f29f1580-0ca0-4c38-8045-a7aea2a8d8fb","http://resolver.tudelft.nl/uuid:f29f1580-0ca0-4c38-8045-a7aea2a8d8fb","Simultaneous drone localization and communication using visible light","Lut, Jasper-Jan (TU Delft Electrical Engineering, Mathematics and Computer Science)","Zuniga, Marco (mentor); Xu, M. (graduation committee); Wang, Q. (graduation committee); Delft University of Technology (degree granting institution)","2023","Drones that perform complex autonomous movements require a perfect estimate of their current position. However, internal measurement unit (IMU) errors introduce drift in this estimate, leading to significant discrepancies between the predicted and actual location. Various solutions have been proposed to calibrate the IMU, including methods involving cameras and humans in the loop. This thesis suggests implementing a previously developed technique that involves projecting a precise static light polarisation grid into a room. Although this pattern is invisible to the human eye it can be observed using a polariser and colour sensor combination. A drone equipped with such a sensor setup can recalibrate for IMU drift by utilising the perceived polarisation patterns as optical landmarks.
The system design is further developed by exploring the potential of visible light communication (VLC) as an alternative to traditional radio frequency (RF) links for drone control. By leveraging the existing infrastructure used for the projection of the polarisation grid, a VLC link is integrated into the system. With the addition this work strives to fuse polarisation-based localisation and VLC,
setting the first steps in creating a fully visible light-based drone platform.
To validate the system, a prototype is created that achieves real-time simultaneous localisation and communication on an embedded drone. This is accomplished through machine learning based classification, a drone motion model, an optimised polarisation pattern enabling fast localisation and a noise-resistant VLC link. Experiments show a median 2D tracking error of 10cm using only light-based methods and a VLC link range of up to 2.5 meters under various conditions.
To evaluate the system's performance, extensive experiments were conducted under different lighting conditions, PWM frequency and Rx-Tx distances. The experiments focused on achieving the maximum achievable throughput while maintaining a low Bit Error Rate (BER). Through careful optimization of the system parameters, a maximum throughput of 4.4kbps was achieved. Furthermore, the system consistently maintained a Bit Error Rate of less than 0.005\%, ensuring reliable and error-free data transmission.
In addition to data transmission, the impact of data transmission on the display's visual quality was investigated. The Delta E value, which quantifies the observed colour difference between two pixel values, was used as a metric for display quality. The data rates were calibrated such that the display operated with a Delta-E value of less than 1 in more than 90\% of the colour spectrum, indicating minimal colour distortion during data transmission.
This study contributes to the field of VLC by showcasing a practical implementation that combines scalability, visual quality, and performance. Future research directions could focus on expanding the display size and enhancing the data rate by means of more sophisticated hardware.","Visible Light Communication; VLC; RGB LED; LED; LED display; Data communication; LED matrix","en","master thesis","","","","","","","","2025-07-06","","","","Electrical Engineering | Embedded Systems","",""
"uuid:10211bcd-63e0-41d1-bb57-4ee244b36c60","http://resolver.tudelft.nl/uuid:10211bcd-63e0-41d1-bb57-4ee244b36c60","Analysis and modelling of light sources for visible light communication","van Mierop, Ron (TU Delft Electrical Engineering, Mathematics and Computer Science)","Isabella, O. (mentor); Manganiello, P. (mentor); Zuniga, Marco (graduation committee); Muttillo, M. (mentor); Delft University of Technology (degree granting institution)","2023","The considerable increase in the number of devices needing connectivity, such as mobile phones and Internet of Things (IoT) devices, has led to an exponential rise in data volumes during the last years, that will surely continue over the next decade. Therefore, it will be increasingly challenging to provide sufficient RF resources. A novel alternative to RF communications is Visible Light Communication (VLC). VLC is a communication technology that uses visible light as an information carrier. The use of VLC for indoor applications has been rapidly growing during the last years – Light Fidelity (LiFi) technology is an example of VLC application – with photodiodes being the most widely used receiving devices. However, looking at both indoor and outdoor communication, photovoltaic (PV) cells represent a relevant alternative for detecting the information. One of the advantages of using a PV cell as receiver is the huge sensitive area for detection of the information that simplifies alignment between transmitter and receiver.
Different light sources can be used in VLC. Typically, either LEDs or LASERs are considered, depending on the characteristics of the link (such as distance, type of receiver, indoor/outdoor application). These light sources differ in terms of spectrum, directionality, optical power density and bandwidth. The performance of the whole VLC link strongly depends on the characteristics of the light source, since it affects the ability of the receiver, such as a PV-device, to detect the information when it overlaps with the ambient light, that can reach very high values, especially in outdoor applications where the ambient light is the sunlight. Therefore, the modelling and analysis of the performance of different light sources in a PV-based VLC link will pave the way towards the realisation of a PV-based communication system of the future; and it is the focus of this thesis project.
The project goals were achieved by first reviewing the characteristics of light sources, to understand their advantages and drawbacks in (PV-based) VLC. This was followed by the development of models of the VLC data-link, with a focus on the light source, which took into account various factors such as the type of light source, its location relative to the receiver, and its dynamic behaviour. This was followed by the realisation of a test setup, to characterise different light sources, and the models were then used to simulate the light distribution from the actual light sources. Finally, the framework was used to simulate a LED-based solar simulator and an outdoor VLC data-link.","Visible light communication; VLC; LED; PV Receiver","en","master thesis","","","","","","","","2025-03-13","","","","Electrical Engineering","",""
"uuid:473c5ba8-c8ad-4c6d-8f1b-ddfbe654b209","http://resolver.tudelft.nl/uuid:473c5ba8-c8ad-4c6d-8f1b-ddfbe654b209","DynamicVLBC: Battery-less Visible Light Backscatter Communication in Dynamic Conditions","de Groot, Lucan (TU Delft Electrical Engineering, Mathematics and Computer Science)","Zuniga, Marco (mentor); Xu, M. (mentor); Yang, J. (graduation committee); Delft University of Technology (degree granting institution)","2022","Visible Light Communication (VLC) has been gaining interest in the industry and academia for the last decade. VLC enables a high-speed communication alternative to conventional radio such as Bluetooth or WiFi and presents a solution to the 'spectrum crunch'. More recently, the combination of energy harvesting and VLC has been explored to enable battery-less devices that can communicate bidirectionally using light. In parallel, drones are being used in the industry for tasks such as warehouse management. However, very little research has been done on the conjunction of VLC and drones, even though this offers interesting research opportunities and applications.
In this thesis, we perform the first evaluation of different types of modulation techniques between a drone and base station in the context of VLC. We present DynamicVLBC: a complete system consisting of a drone ('Reader') and base station ('Tag'). We optimize this system such that the Reader can fly and the Tag can operate battery-less at an ultra-low power level. We thoroughly evaluate the system in both indoor and outdoor conditions. Our evaluations show that when the Reader is static and the Tag is externally powered, that the system can communicate up to 200cm with a BER below 1%. Moreover, when the Tag is operating battery-less, the system can still effectively communicate up to 150cm. Finally, when the Reader is airborne as well, we show that the system can still communicate up to 85cm.","Visible Light Communication; Backscatter; Battery-less; Drones; Dynamic Channel","en","master thesis","","","","","","","","2024-08-30","","","","Electrical Engineering | Embedded Systems","",""
"uuid:195c9053-32c8-4470-9b26-26208e00c41d","http://resolver.tudelft.nl/uuid:195c9053-32c8-4470-9b26-26208e00c41d","Spectrum-aware Passive Visible Light Communication","Dsouza, Vivian (TU Delft Electrical Engineering, Mathematics and Computer Science)","Zuniga, Marco (mentor); Gadiraju, Ujwal (graduation committee); Ghiasi, S.K. (graduation committee); Delft University of Technology (degree granting institution)","2022","The rapidly growing number of wireless devices typically use radio frequency for communication. However, in order to avoid using the expensive and increasingly congested radio bands, research areas are moving in the direction of using ambient light to form physical links in wireless communication systems. Unlike active Visible Light Communication (VLC) which controls the light source itself, passive VLC modulates the ambient light and results in low power transmitters as no energy is required for generation of the carrier wave. Similar to radio waves, visible light is also electromagnetic radiation and has wavelengths in the range of 400-700 nm. All previous work in passive VLC rely on switching the whole spectrum at the same time, and do not completely exploit using the full spectrum of light - reducing potential channel capacity.
In this thesis we propose a novel method to transmit and decode data, using liquid crystal cells that can modulate the spectrum. The main contribution of this thesis is to show that we can move from spectrum-agnostic to spectrum-aware modulation with passive VLC. The work in this thesis focuses on modulation and demodulation of such a communication link, and introduces novel methods of controlling the light spectrum. We build a prototype and demonstrate a multi-symbol communication link, and evaluate it with an effort to maximise the datarate.","Visible Light Communication; Physical link; Spectral Analysis","en","master thesis","","","","","","","","2024-08-25","","","","Electrical Engineering | Embedded Systems","",""
"uuid:020d966a-dd5f-4ead-8224-eaf77530fc0e","http://resolver.tudelft.nl/uuid:020d966a-dd5f-4ead-8224-eaf77530fc0e","System Design of LED-to-Rolling-Shutter-Camera Communication using Color Shift Keying","Durmuş, Merdan (TU Delft Electrical Engineering, Mathematics and Computer Science)","Langendoen, K.G. (mentor); Chavez Tapia, M.A. (mentor); Zuniga, Marco (mentor); Lukina, A. (graduation committee); Delft University of Technology (degree granting institution)","2022","Visible Light Communication (VLC) is becoming an important research area where Visible Light Sources such as LED, Halogen Lamps and even the sun can be used for Wireless Communication. LED-to-Camera Communication is a form of VLC, where the camera can notice intermittent stimuli changes above a certain threshold frequency (flicker fusion frequency) which human eyes cannot no- tice. There exist numerous methods to encode data (= Modulation Schemes) for LED-to-Camera Communication, however, with some modulation schemes, VLC cannot support any practical appli- cations because the achievable data rate either is too low or the system is difficult to be implemented on off-the-shelf devices.
In this paper, we will propose a system design for LED-to-Camera Communication with Color Shift Keying (CSK) as a modulation scheme to encode the transmitted data. In Color Shift Keying, the sys- tem makes use of colors to encode bits, the receiver will then decode the received color into the corre- sponding bits. The proposed design provides a sys- tem outline which may obtain a more practical data rate by using CSK as a modulation method and a CMOS image sensor as receiver. A CMOS image sensor consists of a matrix of photodiodes which combined make up the captured image. The rolling shutter effect makes use of this matrix-like struc- ture by scanning each line separately, by using the rolling shutter effect the camera captures lines with different colors which can be decoded into bits.","Visible Light Communication; Color Shift Keying; Rolling Shutter Camera","en","bachelor thesis","","","","","","","","","","","","Computer Science and Engineering","CSE3000 Research Project",""
"uuid:832509c6-9a68-4228-b5ee-cb47e883512c","http://resolver.tudelft.nl/uuid:832509c6-9a68-4228-b5ee-cb47e883512c","JAB: A generic architecture for power efficient, high throughput mobile VLC applications","van de Beek, Valentijn (TU Delft Electrical Engineering, Mathematics and Computer Science; TU Delft Embedded and Networked Systems)","Langendoen, K.G. (mentor); Zuniga, Marco (mentor); Lukina, A. (graduation committee); Chavez Tapia, M.A. (mentor); Delft University of Technology (degree granting institution)","2022","Visible Light Communication is a method of wireless communication that avoids the oversaturated frequencies used by radio communication. Prior research typically uses the camera on smartphone for communication, but using a camera is energy-intensive and inefficient. Some alternatives are photodiodes and ambient light sensors, however the former is often not available on phones and the latter is too slow to be useful. This thesis introduces a system, JAB, which combines two sensors to achieve high throughput while keeping energy usage low. The impact of distance, modulation frequency and light are measured on the system implemented on an Android smartphone. Overall, the system is usable and does greatly improve the energy effiency of using VLC. An important next step is creating a custom hardware setup with a kernel driver implementation for a full system test.","Visible Light Communication; Android; Smartphones; Ambient Light Sensor; VLC; LiFi","en","bachelor thesis","","","","","","","","","","","","Electrical Engineering","",""
"uuid:d531341d-18f5-4fa0-9b50-d3ab23d5e778","http://resolver.tudelft.nl/uuid:d531341d-18f5-4fa0-9b50-d3ab23d5e778","They could live - encoding invisible information in displays and ways to extract it","Crha, Vojta (TU Delft Electrical Engineering, Mathematics and Computer Science)","Zuniga, Marco (mentor); Chavez Tapia, M.A. (mentor); Zaidman, A.E. (graduation committee); Delft University of Technology (degree granting institution)","2022","In the recent years, several papers have implemented methods which seamlessly integrate data streams into high frame rate monitors without affecting casual viewer experience. This paper proposes an improvement to existing systems which can in theory increase the data throughput of the data stream several times. Exploiting the same characteristics of human vision as related papers, grid containing different colours is encoded into a video. Testing was conducted to determine the possible uses of this approach. It was determined that 2x or even higher increase is possible however there seems to always be a visual artifact present. The testing also revealed a need for further testing to determine the best possible configuration (amount of colours) to use as well. This testing would also increase the reliability of the data gathered as the experiment was limited by time.","Visible Light Communication; Camera to screen communication; Testing","en","bachelor thesis","","","","","","","","","","","","Computer Science and Engineering","CSE3000 Research Project",""
"uuid:d94243cf-9fc8-485e-9eb9-a3c20464d80a","http://resolver.tudelft.nl/uuid:d94243cf-9fc8-485e-9eb9-a3c20464d80a","Blinking LEDs, a potential solution to improve Augmented Reality interactability","Lin, Giovanni (TU Delft Electrical Engineering, Mathematics and Computer Science)","Chavez Tapia, M.A. (mentor); Zuniga, Marco (mentor); Zaidman, A.E. (graduation committee); Delft University of Technology (degree granting institution)","2022","Augmented Reality has the potential to expand our interaction with our surrounding environment. A potential solution to improve this interactability is Visible Light Communication through blinking Light Emitting Diodes (LEDs). Data is encoded and then transmitted by blinking the LED, a smart-phone camera is then pointed at the LED to decode the message from the blinking light. The light must blink at a high enough frequency, otherwise the blinking LED causes flicker which has negative health risks. In this research, an experiment is conducted to check the viability of this technology, by transmitting a message to multiple phones with different recording frame rates and checking whether the technology functions adequately for each frame rate. The viability is checked through multiple factors, with the most important one being flicker, due to the negative health risks. If there is no flicker, the throughput of the LED at that frame rate and blinking frequency is checked at multiple distances. The results show that only the highest recording frame rate used in the experiment is viable and that the ones below all cause flicker. This makes it hard to consider the technology viable, due to it only functioning on a limited amount of smartphones.","Augmented Reality; Visible Light Communication; Smartphone; Tags; Markers","en","bachelor thesis","","","","","","","","","","","","Computer Science and Engineering","CSE3000 Research Project",""
"uuid:6bd857a0-7de2-4e17-8998-79301b3ab184","http://resolver.tudelft.nl/uuid:6bd857a0-7de2-4e17-8998-79301b3ab184","Receiving data through light with low-end smartphones","Hossain, Shaan (TU Delft Electrical Engineering, Mathematics and Computer Science)","Langendoen, K.G. (mentor); Zuniga, Marco (mentor); Lukina, A. (graduation committee); Delft University of Technology (degree granting institution)","2022","Although the demand for wireless communication continuous to grow, the number of frequencies available in traditional data transmission is limited. Visible Light Communication (VLC) is a promising alternative communication method proven to work on high-end devices. However, large-scale adoption requires VLC to also work on everyday machines. Yet, no published research has proven effectiveness on low-end devices. This work describes how a communication system using light can be implement on a low-end smart phone, using a LED as a transmitter. Furthermore, it compares two methods of (de)modulation, namely On-Off Keying and Differential Manchester Code. Evaluation results demonstrate a working system with a maximum bit-rate of approximately 3000bps.","VLC; Demodulate; Visible Light Communication","en","bachelor thesis","","","","","","","","","","","","Computer Science and Engineering","CSE3000 Research Project",""
"uuid:9a25ca94-7cd3-420c-a829-ecb321725b12","http://resolver.tudelft.nl/uuid:9a25ca94-7cd3-420c-a829-ecb321725b12","ChromaCam: Demodulating Colored Light with a High-End Smartphone","Kemmeren, Eric (TU Delft Electrical Engineering, Mathematics and Computer Science)","Langendoen, K.G. (mentor); Chavez Tapia, M.A. (mentor); Lukina, A. (graduation committee); Delft University of Technology (degree granting institution)","2022","Visible Light Communication (VLC) has seen drastic improvements in recent years, one approach uses active light sources like LEDs, switching them at hight speeds to send data. Another approach uses the fundamental characteristics of liquid crystals (birefringence and thickness) to transmit data to a single pixel receiver. These characteristics allow for alterations in the color of the light. Little power is being used to transmit this data in comparison with using LEDs, and is significant faster than switching the LCs fully on or off like other research has done. This paper proposes an algorithm to decode the data transmitted by LCs with a high-end smartphone instead of the single pixel receiver. This algorithm called ChromaCam has real time transmitter detection and decoding of data. A demonstration is shown using a prototype, achieving data rates of 31 bits per second.","Visible Light Communication; Liquid Crystal Displays; CMOS Camera","en","bachelor thesis","","","","","","","","","","","","Computer Science and Engineering","CSE3000 Research Project",""
"uuid:70647c89-899d-4ce9-a3aa-f05f806dfce9","http://resolver.tudelft.nl/uuid:70647c89-899d-4ce9-a3aa-f05f806dfce9","Integrated Communication and Sensing with RGB LEDs","YAN, YIXUN (TU Delft Electrical Engineering, Mathematics and Computer Science)","Wang, Q. (mentor); Kuipers, F.A. (graduation committee); Delft University of Technology (degree granting institution)","2021","Visible Light Communication (VLC) has gained popularity due to its inherent security as a complementary technology to Radio Frequency (RF) in the last decades to solve the ""spectrum crunch'' problem. Meanwhile, The latest IEEE 802.11ah standard, also called WiFi HaLow, offers the range, throughput, and low power consumption that is extremely suitable for most simple IoT appliances for industrial, agricultural, and smart city environments. In general, these IoT products are connected in huge numbers. Hence, provisioning these simple IoT products that usually do not have any user interface like a keyboard or a display in a simple, robust, secure, and scalable method is a significant challenge.
VLC technology has been intriguing both industry and academia for connecting IoT products over the last few years. The signals used in VLC, the visible light, can be captured by eyes and be confined by walls and other blockages which introduce the security against eavesdropping. Besides, the features of low deployment cost, high throughput and high security make VLC a solution to provision IoT products securely. This project exploits on-device existing RGB LEDs to achieve a low-cost and secure device provision system called Integrated Visible Light Communication and Sensing (I-VLCS) System with the functionality of the integrated communication and sensing with RGB LEDs. Visible Light Positioning (VLP), a subset of Visible Light Sensing, is also used in the I-VLCS system to further improve the system security. The performance of the proposed I-VLCS system is evaluated through experiments, demonstrating that that the system can support a maximum 50 cm of communication range with a high communication and positioning accuracy.","Visible Light Communication; Light emitting diodes; Communication system security","en","master thesis","","","","","","","","2023-04-01","","","","Electrical Engineering | Embedded Systems","",""
"uuid:99f57016-e503-4bda-b1ac-d47a64a1e7d8","http://resolver.tudelft.nl/uuid:99f57016-e503-4bda-b1ac-d47a64a1e7d8","Designing an optical link between a micro-display and a smartphone camera","Wu, Zehang (TU Delft Electrical Engineering, Mathematics and Computer Science)","Zuniga, Marco (mentor); Chavez Tapia, M.A. (mentor); Delft University of Technology (degree granting institution)","2021","The popularity of various wireless communication applications is crowding the radio spectrum. As an alternative medium, the visible light spectrum is be- ing exploited. Camera-based visible light communication systems are gaining much attention due to the widespread use of smartphones equipped with small embedded cameras. Screens (e.g., liquid-crystal displays) are ideal choices as multi-pixel transmitters that can send high-capacity packets continuously. Al- though there are many works on screen-to-camera links, only very few are ex- ploiting micro-screens as transmitters. State-of-arts are mainly optimizing the performance of the optical link, less attention is paid to the system’s com- pleteness and practical applications. Thus, the goal of this work is to deliver a self-contained visible light communication system that can send information over a micro-screen-to-camera link at a high data rate.
To achieve our goal, an Android application with real-time image reading and processing is developed. Furthermore, a multi-transmitter system is designed to increase the bandwidth of the communication channel and the system is tweaked to transmit information at a high frame rate. The evaluation results show that this work improves the data rate by over 7-fold, from a baseline of 1.5 kbps to 11.4 kbps. Additionally, a standalone prototype is built based on a Raspberry Pi Zero W. Finally, to showcase the potential of the platform, a smart-city application is developed, where users can download information from Google Maps with the newly developed optical link.
Although the result of this project is encouraging, there is much room for improvement. We envision this work will motivate more research near-field, especially on micro-screen-to-camera links.","Visible light communication; Screen-to-camera link; Smartphone","en","master thesis","","","","","","","","2023-11-17","","","","Electrical Engineering | Embedded Systems","",""
"uuid:234d5e0e-5617-446d-9cac-75ee4c41fca8","http://resolver.tudelft.nl/uuid:234d5e0e-5617-446d-9cac-75ee4c41fca8","Communication with Ambient Light using Digital Micromirror Devices","Blokker, Roy (TU Delft Electrical Engineering, Mathematics and Computer Science)","Zuniga, Marco (mentor); Lofi, C. (graduation committee); Delft University of Technology (degree granting institution)","2021","Passive visible light communication (VLC) takes advantage of the pervasive
nature of ambient light in our environment for wireless transmissions. The
design of transmitters in passive VLC predominantly uses Liquid Crystal Displays (LCD’s). While LCD’s are an economical choice with low power consumption, they lack some key properties that are desirable for passive VLC.
For example, LCD’s absorb more than half of the incident light, leaving only
a small portion to be used for communication. In addition, since the direction
of ambient light can change over time, the relative positions of the LCD’s and
receivers have to be adjusted constantly to maintain the correct alignment. To
overcome these shortcomings, this thesis proposes the use of a novel transmitter
with integrated optical fibres and digital micro-mirror devices (DMD’s). DMD’s
are able to reflect up to 97% of the incident light, while the accompanying optical fibres aim to capture ambient light from various angles and guide them to
the DMD’s in a fixed direction. This design is a first step towards the goal of
decoupling the direction of ambient light from the direction of the optical link,
while achieving the same communication characteristics as LCD’s with a much
smaller device. Furthermore. this thesis describes an app to allow users to easily
interact with the system. An evaluation shows that the link can achieve a data
rate up to 1bps at a distance of 60cm.","VLC; DMD; Passive Communication; Visible Light Communication","en","master thesis","","","","","","","","","","","","Electrical Engineering | Embedded Systems","",""
"uuid:cad0975a-43b0-4c1e-9d03-837df026020f","http://resolver.tudelft.nl/uuid:cad0975a-43b0-4c1e-9d03-837df026020f","Passive Visible Light Communication: Utilizing the Unstable Region Of Liquid Crystals","Wervers, Michel (TU Delft Electrical Engineering, Mathematics and Computer Science; TU Delft Embedded Systems)","Langendoen, K.G. (mentor); Ghiasi, S.K. (mentor); Al-Ars, Z. (graduation committee); Delft University of Technology (degree granting institution)","2021","As more and more devices have become wireless, the traditional Radio Frequency (RF) spectrum has become densely populated. To relieve this pressure, communication using light, visible light communication (VLC), has been proposed by many researchers. However, not all light sources can be modulated to transmit information. Therefore, the use of materials that can change their state between translucent and opaque has often been investigated in order to modulate light. ChromaLux is a recent system that uses such a material. It uses Liquid Crystal shutters to transmit information. However, instead of a single crystal, a stack of crystals is used, which exposes an extra transient region. This transient region shows several peaks that allow faster communication, but makes the system unstable. This thesis addresses several issues that ChromaLux experiences, in order to improve the performance. The system is changed from open-loop to closed-loop, creating a stable system that reaches higher speeds. However, in order to achieve this, part of the crystals is blocked, causing a lower Signal-to-Noise Ratio (SNR). For shorter distances up to 1 m, we are able to increase the data rate by 140 %, while at longer distances of up to 3 m we achieve an increase of up to 92 %. A second improvement which increases the SNR of the system, is the smart use of differential amplification. This allows communication at even greater distances of at least 5 meters.","Passive visible light communication; Liquid crystals; Wireless Communication","en","master thesis","","","","","","","","","","","","Electrical Engineering | Embedded Systems","",""
"uuid:b6637f53-4d37-4e79-a184-240bc2c4f32d","http://resolver.tudelft.nl/uuid:b6637f53-4d37-4e79-a184-240bc2c4f32d","Increasing the Performance of Passive Communication with Ambient Light","Haris Suwignyo, Haris (TU Delft Electrical Engineering, Mathematics and Computer Science; TU Delft Embedded and Networked Systems)","Zuniga, Marco (mentor); Langendoen, K.G. (graduation committee); Al-Ars, Z. (graduation committee); Delft University of Technology (degree granting institution)","2019","Most wireless communication technologies have been using the Radio Frequency (RF) spectrum for decades. Due to the popularity of the Internet of Things (IoT), the RF spectrum has started to become densely populated. Researchers have begun to explore other bands of the electromagnetic spectrum that can be utilized as a communication media. One of the promising choices is the visible light spectrum.
Visible Light Communication (VLC) refers to the wireless communication technology that utilizes the visible light spectrum. This spectrum is thousands of times wider than the Radio Frequency (RF) spectrum and is license-free. In VLC, data is transmitted by turning a light source on and off. However, not every light source can be controlled. Passive light sources such as the sun provide an immense amount of light that can be used for wireless communication if we can develop ways to modulate them.
One of the researches that use ambient light to create a wireless link is LuxLink. LuxLink uses liquid crystal shutters to control passive light sources and provides low energy, reliable, and flicker-free (safe) communication. This thesis addresses several problems that the current LuxLink system has.
We present LuxLink+, an extension of LuxLink that provides two main improvements. Firstly, the data rate of the system is relatively low (80~bps). To increase the data rate, we provide a thorough analysis of the system’s bandwidth. Afterward, we modify the modulation technique, which increases the data rate to 1000~bps at a range of 1.5~m.
Secondly, the system has a static data rate, which means that the system cannot adapt its data rate to changes in the environment. We implement a rate adaptation algorithm that can change its data rate accordingly. LuxLink+ improves the average throughput of the system by up to 85 percent compared to LuxLink.","visible light communication; passive communication; ambient light","en","master thesis","","","","","","","","2020-08-21","","","","Electrical Engineering | Embedded Systems","",""
"uuid:167a3e1a-5d54-45d1-87fc-dc4f1f7be9e5","http://resolver.tudelft.nl/uuid:167a3e1a-5d54-45d1-87fc-dc4f1f7be9e5","Channel Analysis for Passive Communication with Ambient Light","Bloom, Rens (TU Delft Electrical Engineering, Mathematics and Computer Science; TU Delft Embedded and Networked Systems)","Zuniga, Marco (mentor); Langendoen, K.G. (graduation committee); Al-Ars, Z. (graduation committee); Delft University of Technology (degree granting institution)","2017","The idea of the internet of things (IoT) states that devices with embedded electronics will outnumber the devices operated by humans. All those ""things"" will require connectivity to exchange information gathered from processed sensor data. A large part of the data will be sent through the air, such that mobile devices can be deployed without a need to connect any wire. Radio frequencies are widely used for wireless communication and include many systems like WiFi, Bluetooth, FM radio stations and mobile telephony. The capacity of radio channels is limited, thus IoT devices might require different methods for communication.
In this work we study the behaviour of a relatively new communication channel, called the passive light channel. The passive light channel uses reflections of light to send information in the visible spectrum.
It works a bit similar to barcode readers in stores, but it doesn't require a laser. It is sufficient to reflect sunlight or light from other sources, providing a sustainable method of transmitting information.
Patterns consisting of black and white parts, or barcodes in particular, are used to regulate the reflected light. A light sensor is used to detect the reflected light and read the information from the reflected light. The key question in this research is how much information we can convey in such manner.
In this work we show our three main contributions. First, we show that the passive light channel works with barcodes and reflections of ambient light. Second, a mathematical model and simulation tools are presented that describe the behaviour of the channel.
Finally, the performance of the passive light channel with ambient light is analysed using empirical testbeds and compared with results of optical simulations.","Passive Sensing; Visible light communication; communication channel; diffuse reflections","en","master thesis","","","","","","","","2019-03-14","","","","Electrical Engineering | Embedded Systems","",""
"uuid:707eade1-b9c6-46ad-a39e-d9c6b223ea17","http://resolver.tudelft.nl/uuid:707eade1-b9c6-46ad-a39e-d9c6b223ea17","Pulse-Based Modulation for VLC Systems: Using Programmable Systems-on-Chip","Johannsson, Bjarki (TU Delft Electrical Engineering, Mathematics and Computer Science; TU Delft Software Technology)","Langendoen, K.G. (mentor); Delft University of Technology (degree granting institution)","2017","The use of Light Emitting Diodes (LED) as a main source of illumination
can help in significantly reducing global energy conspumtions. The LED is
well suited for modulating visible light, enabling a wireless communication
channel. A popular topic in Visible Light Communication (VLC) research
is to push data throughput past the LED bandwidth limitation of around
4-5 MHz. Less attention has been given to systems using cheaper and slower
components.
This thesis focuses on effectively utilizing the available bandwidth in low
cost dimmable VLC systems, to allow for increased data throughput, where
the system bandwidth is limited by the receiver. Non-
ickering constant
perceived light intensity must furthermore be maintained under variable
dimming conditions, to ensure positive user experience.
A novel modulation scheme for VLC systems with dimming support is pro-
posed. Adaptive Rectified Pulse-Width Modulation (ARPWM) modulates
the light source with fine-grained pulses within a defined symbol period. The
symbols are demodulated as light intensity levels. This allows for sending
multiple bits per symbol in a manner similar to Pulse Amplitude Modula-
tion (PAM). Upper and lower boundaries are applied to the duty cycle of
the pulses according to the desired dimming level, reducing the number of
light compensation symbols needed to maintain a constant perceived light
intensity for the user.
ARPWM is compared to existing modulation schemes, and a throughput
increase by a factor of 4.3 was observed compared to state-of-the-art Vari-
able On-Off Keying (VOOK). With the testbed used for the experiments
we have demonstrated the use of ARPWM in an indoor office environment,
with a maximum communication distance of 4.2 meters in a low-noise en-
vironment.
ARPWM is shown to offer valuable increase in data troughput at a low
complexity level. The relatively high SNR requirements of ARPWM make
it best suitable for short-range indoor VLC.","Visible light communication; modulation; programmable system on chip","en","master thesis","","","","","","","","","","","","Electrical Engineering | Embedded Systems","",""
"uuid:6dc20955-c2ff-48b4-aa3c-1f91dffccba0","http://resolver.tudelft.nl/uuid:6dc20955-c2ff-48b4-aa3c-1f91dffccba0","DynaLight: A Dynamic Visible Light Communication Link for Smartphones","Vasilakis, M.","Zuniga Zamalloa, M.A. (mentor)","2015","Nowadays, Visible Light Communication (VLC) has attracted the attention of the scientific community due to its great potential in creating smart communication links. Exploiting visible light modulations, could in time enable Internet connectivity via light lamps. Recent research studies have shown that modern smartphones have the ability to capture high frequency light patterns and increase the applicability of VLC links, enabling smart applications. However, creating flexible camera-based VLC links brings-up several challenges that are introduced by the diversity of the available devices. Firstly, existing VLC systems offer inflexible setups that are designed to operate at fixed distances. This fact causes problems when it comes to varying the distance between the transmitter and the receiver. This thesis introduces DynaLight: an adaptive line-of-sight VLC system for smartphones that dynamically adjusts and maximizes its channel capacity by estimating the distance between the transmitter and the receiver. Secondly, the wide diversity in smartphones’ hardware introduces problems when it comes to implementing a generic VLC link for market smartphones. In order to increase the applicability of our system, we chose to utilize inexpensive hardware, that introduce performance limitations, such as limited camera control. We present an image processing pipeline that identifies and overcomes effects that are caused by off-the-shelf hardware, and we further increase the amount of information, that can be extracted, by 40%. Last but not least, we develop a smartphone application that implements our enhancements and draws attention to synchronization challenges. Our conclusions indicate that the applicability of smartphone VLC links will be further extended due to the rapid evolution of modern smartphones.","Visible Light Communication (VLC); Smartphones; Camera-based VLC; Data Communication; Dynamic Channel Capacity","en","master thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Embedded Software","","Embedded Systems","",""
"uuid:81b3059f-42b9-47b6-b60e-c610fee0a07d","http://resolver.tudelft.nl/uuid:81b3059f-42b9-47b6-b60e-c610fee0a07d","Networked Indoor Lighting Controls with Visible Light Communication","Warmerdam, K.P.","Zuniga, M. (mentor)","2015","","lighting control; visible light communication; MIMO system","en","master thesis","","","","","","","","2016-01-19","Electrical Engineering, Mathematics and Computer Science","Embedded Software","","Embedded Systems","",""
"uuid:439b72d1-0a8b-4132-8370-b539c8a13574","http://resolver.tudelft.nl/uuid:439b72d1-0a8b-4132-8370-b539c8a13574","Design of a network stack for directional visible light communication","Klaver, L.P.","Zuniga, M. (mentor)","2014","During the last years, Visible light communication (VLC), a novel technology that enables standard Light-Emitting-Diodes (LEDs) to transmit data, is gaining significant attention. In the near future, this technology could enable devices containing LEDs –such as car lights, city lights, screens and home appliances– to form their own networks. VLC, however, is currently limited to point-to-point communication. To unleash the full potential of VLC, more advance network capabilities are required. This Master Thesis presents the design and implementation of a novel research platform aimed at distributed multi-hop visible light communication. Compared to state-of-the-art platforms, our platform provides similar data rates and coverage, but adds two unique characteristics: (i) 360 degree coverage, which is necessary to investigate an important property of LED communication: directionality, and (ii) a flexible design, which allows our platform to be connected to many experimental boards such as Arduino, Beaglebone, Raspberry Pi and sensor nodes. We evaluate the communication properties of our board (link quality, neighbor discovery and packet forwarding), and hope that our work will lower the entry barrier for members of the pervasive and networking communities to investigate and exploit future LED-based networks.","visible light communication; VLC; directional; networking; multihop networking","en","master thesis","","","","","","","","","Electrical Engineering, Mathematics and Computer Science","Embedded Software","","Embedded Systems","",""
"uuid:e324bf20-cd6a-47a3-8706-841c9a5afb5c","http://resolver.tudelft.nl/uuid:e324bf20-cd6a-47a3-8706-841c9a5afb5c","Het ontwerp van Smart Shelf Labels voor LEDSpeak","Van 't Hof, S.A.; Wensveen, M.H.","Leus, G.J.T. (mentor); Van Waterschoot, T.J.M. (mentor)","2011","Leds zorgen voor een revolutie op het gebied van verlichting. Vergeleken met gloeilampen zijn ze meer energiezuinig en kunnen ze sneller schakelen. Dat maakt energie-efficiënte lichtcommunicatie mogelijk. Het onderwerp van ons onderzoek is “communicatie via leds”. Wij passen dit toe in de automatisering van prijsaanduidingen in warenhuizen, door middel van elektronische prijskaartjes (Smart Shelf Labels, SSLs). Het doel van dit verslag is het presenteren van een ontwerp van een ontvanger voor communicatie via leds, in de vorm van een SSL.","Visible light communications; Electronic shelf label; Digitaal prijskaartje","nl","bachelor thesis","","","","","","","","2011-06-30","Electrical Engineering, Mathematics and Computer Science","Microelectronics & Computer Engineering","","Circuits and Systems","",""