JJ
J. Jonk
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1
Due to trends such as the Internet of Things, there has been a growing number of devices that use wireless technologies for communication. This increase leads to bandwidth limitations that forced researchers to explore other types of wireless communication. One of these alternatives is Visible Light Communication (VLC). VLC encodes data by rapidly changing the intensity of a source emitting light in the visible spectrum. One branch of VLC is Passive VLC. Passive VLC uses ambient light, such as sunlight or ceiling lamps, as a source. An advantage of this approach is the drastically reduced power consumption. Since the light is already present, no energy has to be used to power a source. However, a flaw of Passive VLC is the lower throughput due to limitations in the available modulation devices. This thesis aims to mitigate the limited throughput by creating separate independent bands that can simultaneously transmit data. Taking advantage of the relatively wide visible light spectrum, the use of colour filters will be explored to divide the spectrum into distinct bands where independent data can be transmitted. To keep it as accessible as possible, there is a focus on low-cost filters, reducing computational complexity and real-time communication. A characterisation of low-cost colour filters is presented as well as a channel estimation algorithm to mitigate the shortcomings of inexpensive filters. To reduce the computational overhead, an encoding algorithm is presented that drastically reduces the computation needed to decode data. Ultimately, we provide a physical platform that achieves multi-channel passive VLC by exploiting cost-effective colour filters. The platform allows for simple expansion to greater numbers of channels as well as real-time communication due to the ability to adjust to the surrounding conditions.
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Due to trends such as the Internet of Things, there has been a growing number of devices that use wireless technologies for communication. This increase leads to bandwidth limitations that forced researchers to explore other types of wireless communication. One of these alternatives is Visible Light Communication (VLC). VLC encodes data by rapidly changing the intensity of a source emitting light in the visible spectrum. One branch of VLC is Passive VLC. Passive VLC uses ambient light, such as sunlight or ceiling lamps, as a source. An advantage of this approach is the drastically reduced power consumption. Since the light is already present, no energy has to be used to power a source. However, a flaw of Passive VLC is the lower throughput due to limitations in the available modulation devices. This thesis aims to mitigate the limited throughput by creating separate independent bands that can simultaneously transmit data. Taking advantage of the relatively wide visible light spectrum, the use of colour filters will be explored to divide the spectrum into distinct bands where independent data can be transmitted. To keep it as accessible as possible, there is a focus on low-cost filters, reducing computational complexity and real-time communication. A characterisation of low-cost colour filters is presented as well as a channel estimation algorithm to mitigate the shortcomings of inexpensive filters. To reduce the computational overhead, an encoding algorithm is presented that drastically reduces the computation needed to decode data. Ultimately, we provide a physical platform that achieves multi-channel passive VLC by exploiting cost-effective colour filters. The platform allows for simple expansion to greater numbers of channels as well as real-time communication due to the ability to adjust to the surrounding conditions.
Design of a deep sea LiDAR system
Beam steering design
Though several sensors are available for underwater scanning and ranging, they all have their limits. SONAR sensors are limited in resolution, and scanning mechanisms using a form of light for carrying the data suffer from high attenuation in turbid waters.
The goal of this project was to design a LiDAR system that is capable of overcoming these limitations. To tackle this problem, three groups were formed that focused on different parts of the LiDAR. However, first a complete system overview has been created by the entire project team. First a literature research has been performed. After that, system wide design decisions were discussed and made and also requirements were set. From there on, every subgroup would focus on their own part of the system. In this thesis a more detailed description of the beam steering module shall be given. Again some literature research has been performed. After that, the design decisions were made, based on the requirements. Finally a design was implemented and tested.
For the beam steering module to be successful, it should provide accurate control over the angle at which the laser beam is sent out. Though improvements can be made, the system does comply to the minimum accuracy requirement. ...
The goal of this project was to design a LiDAR system that is capable of overcoming these limitations. To tackle this problem, three groups were formed that focused on different parts of the LiDAR. However, first a complete system overview has been created by the entire project team. First a literature research has been performed. After that, system wide design decisions were discussed and made and also requirements were set. From there on, every subgroup would focus on their own part of the system. In this thesis a more detailed description of the beam steering module shall be given. Again some literature research has been performed. After that, the design decisions were made, based on the requirements. Finally a design was implemented and tested.
For the beam steering module to be successful, it should provide accurate control over the angle at which the laser beam is sent out. Though improvements can be made, the system does comply to the minimum accuracy requirement. ...
Though several sensors are available for underwater scanning and ranging, they all have their limits. SONAR sensors are limited in resolution, and scanning mechanisms using a form of light for carrying the data suffer from high attenuation in turbid waters.
The goal of this project was to design a LiDAR system that is capable of overcoming these limitations. To tackle this problem, three groups were formed that focused on different parts of the LiDAR. However, first a complete system overview has been created by the entire project team. First a literature research has been performed. After that, system wide design decisions were discussed and made and also requirements were set. From there on, every subgroup would focus on their own part of the system. In this thesis a more detailed description of the beam steering module shall be given. Again some literature research has been performed. After that, the design decisions were made, based on the requirements. Finally a design was implemented and tested.
For the beam steering module to be successful, it should provide accurate control over the angle at which the laser beam is sent out. Though improvements can be made, the system does comply to the minimum accuracy requirement.
The goal of this project was to design a LiDAR system that is capable of overcoming these limitations. To tackle this problem, three groups were formed that focused on different parts of the LiDAR. However, first a complete system overview has been created by the entire project team. First a literature research has been performed. After that, system wide design decisions were discussed and made and also requirements were set. From there on, every subgroup would focus on their own part of the system. In this thesis a more detailed description of the beam steering module shall be given. Again some literature research has been performed. After that, the design decisions were made, based on the requirements. Finally a design was implemented and tested.
For the beam steering module to be successful, it should provide accurate control over the angle at which the laser beam is sent out. Though improvements can be made, the system does comply to the minimum accuracy requirement.