PhD Project Opportunities
Below is a list of potential PhD projects available within our research group. Please get in touch with the relevant project supervisor to discuss.
5G mmWave V2X communications
Vehicular communications are seen as key enablers for smart vehicles and intelligent autonomous operation. Connected vehicles can use wireless communications to exchange the sensor data required for autonomous driving. They can support infotainment and safety applications and enable the vehicle to intelligently interact with its environment. As automation increases, vehicles must carry numerous sensors that generate high data rate streams. Current networks such as 802.11p and LTE do not support the gigabit-per-second data rates required for sensor data exchange between vehicles and infrastructure. Recently, millimeter wave (mmWave) techniques have been introduced as a means of achieving such high data rate streams.
5G mmWave communications will be explored for high data rate delivery and optimised for mobility. Multiple antennas and adaptive beamforming will be considered to increase throughout and coverage. The use of multiple antenna elements enables the use of beamforming to focus energy towards a specific vehicle. The channel conditions at these frequencies will be modelled since the use of higher frequencies faces challenges in increased attenuation losses and rapid channel variations. However, GPS enabled vehicles have good location information and when coupled with velocity data the position of the vehicle can be accurately predicted over short time frames. Navigation route data, as well as GPS and velocity can be used for location prediction. Beam switching architectures can reduce the amount of repointing required by leveraging this position information. Multiple antenna elements also allow for spatial filtering and thus can substantially reduce interference and can also reduce Doppler spread.
In this project we will investigate high data rate 5G vehicular communications for different vehicle speeds and suitable beam selection and beam tracking algorithms. Both vehicle to vehicle and vehicle to infrastructure communications will be considered.
5G NR mmWave Gigabit systems
5G New Radio (5G-NR) in the mmWave bands will explore new ways to achieve high data rates and low latency to user equipment. 5G-NR is expected to provide peak data rates of 10Gbps, supporting 3D immersive viewing systems and telepresence services on mobile devices. Reduced end-to-end latencies will support new real time interactive applications and ensure ultra-responsive mobile cloud-services. 5G-NR systems will offer highly improved and consistent QoE to users and serve diverse applications, such as multimedia, virtual reality, Machine-to-Machine (M2M) /Internet of Things (IoT), automotive and air drones. Currently the 26GHz and 28GHz bands are considered by 3GPP 5G-NR for ultra-high speed access and backhaul systems. Apart from analogue beamforming, research in mmWave frequencies considers the combination of analogue and digital processing, known as hybrid beamforming, which benefits from both the array gain provided by the analogue beamforming and the multiplexing gain given by the digital precoding. Non orthogonal multiple access (NOMA) techniques allow multiple users to share the same resources and can enhance system capacity and accommodate massive connectivity. The application of NOMA to a hybrid precoding design in mmWave systems will be explored. Scheduling approaches and the design of low-complexity hybrid analogue-digital precoding algorithms for multi-user mmWave systems will be considered.
Advanced signal processing algorithms for future wireless transmitters’ linearisation.
Wireless transmitters account for most of the energy consumption of communication systems. The power amplifier (PA) is the most energy hungry component and operating it in an efficient manner is highly desirable. Unfortunately, highly efficient PA architectures are strongly nonlinear. This results in intolerable signal degradation and QoS. Several linearisation techniques are used to cancel the nonlinear behaviour of PAs. The most used one is digital Pre-distortion (DPD). All DPD methods rely on constantly monitoring the output signal of a PA in order to identify its nonlinear behaviour. This comes at a cost of an additional energy consumption that could offset the benefit of the PA efficient architecture. The additional DPD energy consumption is due to the use of high speed analogue-to-digital-converters (ADCs) as well as the signal digital processing (DSP) required.
This PhD aims to investigate DSP algorithms that are energy efficient. The approach consists of identifying which nonlinear components are more relevant to cancel in the presence future wireless standards signal waveforms. Additionally, new monitoring architecture based on low speed ADCs to avoid the unaffordable energy consumption of fast ADCs. Techniques such as under-sampled vector signal analysis will be investigated, and a theoretical framework will be developed to propose a step by step guide to how to implement a robust and efficient DPD.
The outcome of this PhD can be applied to current, very near and long-term future wireless communication systems.
The PhD supervising team has a proven track record in PA characterisation, design and linearisation. As part of the Communication Systems and Networks group, the RF research team is maintaining a heavy research and development activity in this domain.
Highly integrated ultra-Massive MIMO system for future wireless communication systems.
5G and future wireless communication systems will require disruptive technologies to be deployed to overcome the difficulties of transmitting signals in highly spectral-efficient way for sub-6GHz frequencies and reliably for mm-Wave frequencies. Massive MIMO systems offer these desired capabilities as it has been already proven by the CSN research team by holding a world record in spectral-efficiency using a massive MIMO system. This was achieved using industry based hardware for proof of concept. The proposed PhD aims to build a highly integrated massive MIMO system in the form of an active antenna array composed of thousands of radiating elements. The prototype that will be built will hold a world record in terms of number of elements and efficiency. Firstly, the PhD will investigate the most relevant massive MIMO scenarios in terms of digital and hybrid phased-array architectures. Secondly, the integration of the RF chain to the radiating elements will be investigated with a robust multi-physics modelling approach in order to come up with a theoretical framework of how to successfully design an active phased-array transceiver. Innovations in multi-parameters nonlinear behavioural modelling and antenna design will be targeted.
Optically Reconfigurable Microwave and MillimetreWave Circuits and Antennas
Reconfigurable (or tuneable) circuits have a huge number of applications from military and commercial radar systems to smart antennas for mobile phones. Conventional tuning is performed with diodes or Micro-Electro-Mechanical Systems (MEMS) switches. However, these approaches have significant drawbacks as systems become more complex and move to higher frequencies, which is anticipated for 5G systems. This number of electrons are generated from a Plasma which acts like a metal at microwave frequencies. Thus light can be used to write microwave circuits and antennas. This project will study light generated microwave circuits and antennas and investigate the required light intensity, wavelengths and microwave performance. (http://www.bristol.ac.uk/news /2017/november/5g-applications.html)
Ad hoc positions are often available and we are keen to hear from exceptional candidates with proposed research topics. For more information on how to apply, studentships, scholarships, other opportunities please click on the relevant drop down below.
How to Apply
Ad hoc positions are often available and we are keen to hear from exceptional candidates with proposed research topics. All proposed projects should be sent to email@example.com with an accompanying CV.
To apply, please submit a PhD application using the online application: http://www.bristol.ac.uk/study/postgraduate/apply/
For information about MSc and PhD opportunities in Wireless & Communication please see here.
Studentships may be available to suitably qualified UK and in some cases EU citizens. Bursaries may be considerably enhanced by industrial topups depending on the project, and candidates qualifications and experience. In all cases a good honours degree in Engineering, Physics, Chemistry, Materials, Mathematics or a related discipline is required. Post-Doctoral Research Assistantships are also available for candidates with relevant experience.
PhD Scholarships are open to UK students and allow the candidate and prospective supervisors to work out a topic of mutual interest. Applications are assessed on receipt. Applications from Year-3 students on a four-year course are welcome now, for start after completion of their course. The funding pays for a tax-free stipend of at least £15,000pa, a research and travel budget, and University fees. Applicants should be on track to obtaining a 1st class degree in Engineering Science, Electrical and Electronic Engineering, Physics, Materials, Engineering Mathematics, or similar.
Bristol Doctorate Chinese Scholarships
For information on the Chinese Scholarship Programme please see here.
Opportunities across the University can be found on Working at Bristol and EPSRC Centre for Doctoral Training in Communications