The ComSysLab is home to research in Photonic Systems, Optical Technology, Wireless Communications, Machine Learning and Nanoscale Communications. The fundamental advances in the laboratory will produce impact in areas such as next generation mobile data networks, vehicular communications and future healthcare monitoring systems.
The ComSysLab is one of the UK’s leading centres for optical wireless communications; the transmission of information in free space using an optical carrier. Optical wireless is attractive because it offers very broad bandwidths with no spectrum congestion (or charges) and does not suffer from RF interference. In order to advance the technology, new optical receiver-detector devices are being investigated, especially the photoparametric amplifier, which combines advantageously optical detection with parametric amplification. In addition, diffuse optical distribution systems are being developed, in order that users can operate anywhere within a building environment, and be offered a consistent quality of service.
In recent years there has been rapid progress in the development of nanoscale devices, commonly grouped under the heading of nanotechnology. The impact of this area arises through the use of very small devices (at the nanometre scale) to perform socially useful tasks ranging from bespoke medical treatments to monitoring the state of painted surfaces. The interconnection of nanoscale devices in an emerging area in which there are still relatively few published results. It is essential that nano-machines are able to communicate to enable them to realise their potential via nanonetworks, and this forms the basis for ongoing study. Mark Leeson organised a special session on Nanoscale Communications and Technology at the CSNDSP 2014 conference in Manchester, UK.
A further strand concerns optical receiver analysis, in particular with respect to the use of optical preamplifiers. To operate a system including an optical preamplifier it is necessary to reduce the amplified spontaneous emission (ASE) noise by use of a filter. Work in the group has focussed on bit error rate analyses including realistic filter characteristics and pulse shapes.
All-optical networks (AONs) are a relatively new technology for high data-rate communications. They contain only optical components and are intrinsically different from optical networks currently being used. More specifically, AONs provide transparent features that allow routing and data switching without necessitating the interpretation or regression of signals within the network.
Consequently, AON components and architectures bring forth a set of new challenges in network security. Novel approaches to the detection of attacks against all optical networks have been investigated with considerable success.
The idea that nodes in a communication network can do more than just forward the traffic that they see has become established in what is known as Network Coding (NC) which improves throughput in multi-hop wireless networks. Current work is focused on evaluating the effects of adopting NC in data link control where flow control error protocols are employed. Specifically, Automatic Repeat reQuest (ARQ) techniques in conjunction with NC are being studied through extensive simulation.
The wireless spectrum in increasingly congested and cognitive radio uses software to provide opportunistic access to the licensed spectrum bands. By sensing the licensed frequency spectrum and identifying vacant channels, it is possible to allow secondary users access to idle channel. Primary users should not suffer service degradation from opportunistic spectrum access and it is the job of the secondary user to manage interference by spectrum sensing. Current work includes the extension of collaborative spectrum sensing to multiple primary user scenarios and different primary user traffic distributions.
Head of Laboratory
- Dr M I Majid
Current PhD Students
- B Shao - Delay Tolerant Networking
- N. Gunes - Stochastic Resonance in Communication Systems
- Y Li (Visiting) - Coherent Communications for Underwater Optical Transmission
- Z. Rong - Nanoscale THz communications
- Y Zhou - Pilot-based energy harvesting
- L Zhang - Smart Homes
Recent PhD Students
- Z Abdul Mutalip - Investigation of optical wireless for employment within a vehicular environment (2016)
- Z Rihawi - Optical Wireless Channel Characterisation in Guided Structures (vehicle applications (2016)
- Y Li - Error Correction Codes for Molecular Communication Systems (2016)
- C Bai - Error Control in Bacterial Quorum Communications (2016)
- F Jasman - Modelling and characterisation of short range underwater optical wireless communication channels (2016)
- L J Johnson - Optical property variability in the underwater optical wireless channel (2015)
- H Du - Optical wireless MIMO communication (2015)
- Y K T Mo - Deterministic ethernet in a safety critical environment (2014)
- K Wang - Performance analysis for cooperative wireless communications (2014)