See also
Communications Research Group - PhD Research Projects
PhD research projects are currently available in the following areas. Some projects listed may also be suitable for the MSc by Research – please contact the member of academic staff involved if you are interested in the MSc by Research. Please note that funding opportunities, if available, are advertised on our Funding page.
- Adaptive coded MIMO-OFDM systems
- Advanced Error-control Coding Techniques
- Cognitive Radio for Multiple Heterogeneous Systems employing Smart Antennas
- Cooperative MIMO techniques for wireless mesh networks
- Crosslayer Design for Cognitive Networks
- Crosslayer Protocol Development for Ad Hoc Networks
- Development of efficient recursive beamforming techniques
- Fast adaptive beamforming for underwater antenna arrays
- Implementation of matrix operations using FPGA
- Implementation of soft-input, soft-output detectors and decoders using FPGA
- Learning and Reasoning Strategies in Cognitive Radio
- Low power medium access control for wireless sensor networks
- Network MIMO for next generation wireless networks
- Novel Cooperative Diversity and Resource Allocation Techniques for Wireless Networks
- Novel Joint Iterative Interference Cancellation, Data Estimation and Decoding Techniques for MIMO networks
- Novel Precoding, Scheduling and Limited-feedback Algorithms for Multiuser MIMO Systems
- Optimal detection of communications signals in imperfectly known channels with many unknown parameters
- Physical Layer Network Coding for Cooperative Wireless Networks
- Spectrum Charging in Cognitive Radio Networks
Adaptive coded MIMO-OFDM systems
Prof Alister Burr, email: agb@ohm.york.ac.uk
The combination of MIMO and OFDM technologies for broadband wireless communications seems likely to dominate future standards like WiFi, WiMAX, and other fourth generation wireless systems. The efficiency of such systems can be greatly increased by making it adaptive to the wireless channel. Moreover FEC coding using codes such as turbo and LDPC codes can also greatly enhance performance. The research will develop new schemes based on these technologies, consider reduced complexity detection and decoding strategies, and also evaluate the overall improvement in system capacity resulting from adaptive coded MIMO-OFDM. This will also require the development of resource allocation and scheduling methods.
Advanced Error-control Coding Techniques
Dr Rodrigo de Lamare, email: rcdl500@ohm.york.ac.uk
In this research project, we will investigate novel encoding and iterative decoding techniques for use in conjunction with Turbo codes, low-density parity-check (LDPC) codes and repeat accumulate codes. Specifically, we will examine novel forms of irregular encoding and more efficient iterative decoding algorithms such as improved versions of the M-best algorithm and list decoding. The research activities will be based on mathematical modeling, and the building of simulation and analytical tools.
Cognitive Radio for Multiple Heterogeneous Systems employing Smart Antennas (also suitable for MSc by research)
Dr David Grace, email: dg@ohm.york.ac.uk
This project will examine how smart antennas can be used with multiple systems (e.g. terrestrial ad hoc, terrestrial cellular, high altitude platform) sharing pooled spectrum. Spectrum assignment strategies will be developed which take into account dynamic changes in the beam pattern of both transmit and receive antennas. The impact of the degree of control information exchange required between the different systems, possibly owned by multiple operators will be addressed. The benefits and drawbacks of such an approach over conventional spectrum assignment methods will be evaluated. A mixture of simulation and analysis will be used to assess performance. Game theory and Markov analysis will be particularly important analytical tools.
Cooperative MIMO techniques for wireless mesh networks
Prof Alister Burr, email: agb@ohm.york.ac.uk
Future wireless networks are likely to consist of very large numbers of cheap, low-power nodes forming very large mesh networks, instead of the conventional cellular or access point architecture that dominates today. It is well known, however, that in large wireless networks congestion rapidly builds up, so that the capacity per node decreases with network size. This project will investigate the use of virtual MIMO techniques, in which groups of nodes cooperate, exploiting MIMO principles, to increase their efficiency and range so as to overcome this congestion bottleneck.
Crosslayer Design for Cognitive Networks (also suitable for MSc by research)
Dr David Grace, email: dg@ohm.york.ac.uk
This project will examine how crosslayer design can be used to improve the performance of future cognitive ad hoc and sensor networks. Spectrum assignment and routing strategies will be developed which take into account dynamic changes in traffic flow throughout a network. The impact of the degree of control information exchange required between multiple networks and nodes sharing the pooled spectrum, possibly owned by multiple operators, will be addressed. The benefits and drawbacks of such an approach over more traditional ad hoc network techniques will be evaluated. A mixture of simulation and analysis will be used to assess performance. Game theory and Markov analysis will be particularly important analytical tools.
Cross-Layer Protocol Development for Ad Hoc Networks
Dr Paul Mitchell, email: pdm106@ohm.york.ac.uk
This research project will explore cross-layer protocol design for ad hoc networks. Protocols that combine medium access control and routing functionality will be developed for energy-constrained ad hoc networks, where great savings in energy and capacity can be made through the use of common signalling mechanisms for both medium access and routing functionality. Simulation and/or analytical models will be developed and the benefits of the proposed techniques evaluated through comparison with current state of the art protocols.
Development of efficient recursive beamforming techniques
Dr Yuriy Zakharov, email: yz1@ohm.york.ac.uk
Antenna array beamforming (smart antennas) is a research area important for many applications, including communications, radars, and sonar. Adaptive antenna arrays enable solving complicated problems that cannot be solved by traditional antennas. Recursive beamforming techniques allow significant reduction in complexity and make it possible software and hardware implementation. The project will develop new antenna beamforming techniques that are well suited to real-time implementation using field programmable gate arrays (FPGA).
Fast adaptive beamforming for underwater antenna arrays
Dr Yuriy Zakharov, email: yz1@ohm.york.ac.uk
Adaptive acoustic antenna arrays that exploit the underwater propagation model (matched field processing) allow significant improvement in performance. However, these techniques are complicated for implementation and suffer from the model mismatch problem. The aim of the project is to develop and investigate new fast adaptive algorithms for underwater acoustic antenna array beamforming, especially arrays with a large number of sensors, that are robust to the model mismatch and well suited to practical real-time implementation.
Implementation of matrix operations using FPGA
Dr Yuriy Zakharov, email: yz1@ohm.york.ac.uk
In many applications, such as communications, radars, sonar, and others, the optimal signal processing requires efficient implementation of matrix operations in real-time. Among these operations are matrix inversion, matrix decompositions, eigenvalue decomposition, solving systems of equations, and others. The project will develop implementations of such matrix operations using field programmable gate arrays (FPGA), focusing firstly on minimising the design area and on maximising the processing speed.
Implementation of soft-input, soft-output detectors and decoders using FPGA
Prof Alister Burr, email: agb@ohm.york.ac.uk
Many emerging wireless communication standards, such as WiMAX and 3GPP LTE, use iteratively-decoded error correcting codes, such as turbo-codes and LDPC, based on soft-input, soft-output (SISO) component decoders. Moreover iterative techniques can be used to improve the performance of other functions, such as detectors and equalisers, and hence SISO detectors/equalisers may also be required. However SISO decoders may be complex and expensive to implement. The project will develop implementations of such components using field programmable gate arrays (FPGA), focusing firstly on minimising the gate count required, and secondly on maximising speed.
Learning and Reasoning Strategies in Cognitive Radio (also suitable for MSc by research)
Dr David Grace, email: dg@ohm.york.ac.uk
This project will explore how different learning and reasoning strategies should be applied to cognitive radio based systems. Strategies could include reinforcement-based learning, possibly applied using game theoretic techniques. By modelling a realistic wireless communications environment, the purpose of the project will be to show how, by applying this form of intelligence, it is possible to improve the flexibility and usage of pooled radio spectrum, both on a local and system wide basis. The project will establish where the learning/reasoning should best reside (nodes and/or network), and also the degree of control information exchange required between nodes. A mixture of simulation and analysis will be used to assess performance.
Low power medium access control for wireless sensor networks
Dr Paul Mitchell, email: pdm106@ohm.york.ac.uk
This research project will investigate issues associated with the development of energy-efficient medium access control (MAC) protocols for wireless sensor networks, identifying key sources of energy waste. The performance of the IEEE 802.15.4 MAC protocol will be studied through analysis, simulation in OPNET Modeler and/or practical implementation in MICA2 devices. Novel ideas will be explored to improve the performance of the 802.15.4 MAC layer for multi-hop communication in a wireless sensor network.
Network MIMO for next generation wireless networks
Prof Alister Burr, email: agb@ohm.york.ac.uk
Next generation wireless telecommunication networks will need to provide greatly increased capacity density. A vital technique for achieving this is likely to be Network MIMO, in which multiple base stations collaborate to provide a single virtual MIMO terminal with an increased number of antennas. This approach is already included in next generation standards, but there are many problems remaining to be overcome. In particular it relies on the availability of a high capacity and reliable backhaul network, which may be difficult to provide when only wireless links are available for the backhaul. The project will investigate methods for reducing the additional backhaul load resulting from network MIMO, and its vulnerability to fading and other outages on the backhaul network. It will use largely computer simulation techniques.
Novel Cooperative Diversity and Resource Allocation Techniques for Wireless Networks
Dr Rodrigo de Lamare, email: rcdl500@ohm.york.ac.uk
Recently, it has been shown that cooperative communications can increase the capacity and the reliability of wireless networks by exploiting a novel form of diversity via cooperation. This project will examine novel cooperative diversity techniques in conjunction with resource allocation algorithms for wireless networks. In particular, we will consider narrowband and OFDM systems and will investigate novel distributed space-time/frequency coding, resource allocation and partner selection algorithms for improving the performance and the capacity of wireless networks. The activities will be based on mathematical formulation, simulation and analytical tools.
Novel Joint Iterative Interference Cancellation, Data Estimation and Decoding Techniques for MIMO networks
Dr Rodrigo de Lamare, email: rcdl500@ohm.york.ac.uk
This project will investigate novel concepts of joint iterative interference cancellation, data estimation and decoding for MIMO networks such as WIMAX, UMTS and future systems. The main idea is to formulate the problem of interference cancellation, parameter estimation and decoding as a joint optimisation problem. We will devise novel cost-effective algorithms for implementing the proposed approach in the uplink of MIMO networks. One significant challenge is how to estimate the channel of co-channel users and we will examine novel ways of determining these parameters. We will then apply the novel algorithms to MIMO systems with multiple cells and evaluate the performance of the proposed algorithms against the best methods available. The research activities will be based on formulating a system model, the building of simulations and analytical tools.
Novel Precoding, Scheduling and Limited-feedback Algorithms for Multiuser MIMO Systems
Dr Rodrigo de Lamare, email: rcdl500@ohm.york.ac.uk
This project will investigate innovative techniques for significantly improving the capacity and the performance of multiuser MIMO networks such as WIMAX and 3GPP-LTE. In order to manage the high-level of interference in these systems, we will devise novel precoding and scheduling algorithms for the downlink of MIMO systems with multiple users and cells. The existence of multiple cells make the design of the precoders and schedulers significantly more challenging and we will examine novel approaches to this scenario. Since these algorithms require the channel state information (CSI), we will also investigate innovative ways of encoding the CSI and sending it via low-rate feedback channels. In particular, we will focus on the scenarios with time-varying channels where limited feedback is quite challenging. The research activities will be based on formulating a system model, the building of simulations and analytical tools.
Optimal detection of communications signals in imperfectly known channels with many unknown parameters
Dr Yuriy Zakharov, email: yz1@ohm.york.ac.uk
In communications, traditional detection techniques are derived based on assumption that the parameters of the communications channel are perfectly known. However, in practice, this is not the case, and the channel should be estimated. In such scenarios, the detection techniques are not optimal anymore. This becomes a significant problem, especially for channels with a large number of unknown parameters, such as multiple input multiple output (MIMO) channels, multipath channels, fast varying mobile channels, and others. This project will develop detection techniques that provide optimal detection when the channel parameters are not perfectly known.
Physical Layer Network Coding for Cooperative Wireless Networks
Prof Alister Burr, email: agb@ohm.york.ac.uk
Network Coding is a new technique for wireless relaying or multi-hop networks in which data received from multiple sources at intermediate nodes is combined and re-coded, instead of being simply selected and forwarded. It has the potential of significantly increasing throughput in multiuser wireless networks: for example it can readily double the capacity of a pair of terminals communicating with one another via a relay. However its application in wireless networks is more complex because of the inherent interference between links, and problems such as fading. The project will exploit a new approach to physical layer network coding, known as soft network-coded modulation, introduced at York in collaboration with other researchers, to find both the limits on the capacity of this approach, and practical implementations of it.
Spectrum Charging in Cognitive Radio Networks (also suitable for MSc by research)
Dr David Grace, email: dg@ohm.york.ac.uk
This project will investigate how spectrum can be charged for in cognitive radio based systems. The project will examine the most effective degree of centralisation required to complete charging transactions, while balancing usability at the radio system level. Coupled with this will be an investigation into techniques that would allow primary users to resell unused spectrum, comparing them with bandwidth broker techniques. The effectiveness of spectrum price levels to control or shape demand will also be investigated. It is likely that auction techniques will prove particularly useful. A mixture of simulation and analysis will be used to assess performance. Linear programming, set theory and game theory will be particularly important analytical tools.
Postgraduate Admissions Tutor: Dr. Steve Smith
Tel: (+44) 01904 324485