Direct Digitisation for Frequency Agile Millimetre Wave Massive MIMO

In recent years there has been a huge explosion in the use of mobile devices such as smartphones, laptop computers and tablets which require a wireless connection to the internet. Numbers are forecast to reach 40 billion worldwide by 2020 as areas as diverse as the home, transport, healthcare, military and infrastructure experience increasing levels of embedded 'smart' functionality and user operability. Major applications such as future 5G communications systems, the Internet of Things and Autonomous Vehicles are driving this technology. At present wireless systems operate at frequencies up to 6GHz. However, there is a growing realisation that the spectrum below 6GHz cannot support the huge data rates being demanded by future users and applications.

The next step is to develop technologies utilising much higher frequencies to give data rates compatible with future demand. Currently, world licencing bodies such as ETSI and ITU have identified millimetre wave frequencies up to 90 GHz as most likely for this expansion in the spectrum. Strategically, the UK must develop wireless technologies to compete on the world stage and increase its competitiveness particularly in competition with the Far East. Superfast 5G level Telecoms infrastructure is central to the Industrial Strategy Green Paper, which the UK government has been championing and highlighting in the ten pillars of combined strategy.

Two technology bottlenecks in millimetre wave receivers, which are important aspects of future communication systems, are: 1) current receiver architectures are unable to directly digitise millimetre wave signals with acceptable power consumption, and 2) antenna arrays are not sufficiently frequency agile. This project aims to address both bottlenecks using new techniques developed on the FARAD project. The proposed research will embrace the co-design of antennas, filters and amplifiers with track-and-hold-amplifiers, analogue-to-digital-convertors and digital down conversion. This will result in new receiver architectures for fully digital massive MIMO systems.

The techniques and architectures developed in this project will enable future high-frequency networks to operate efficiently in the new millimetre wave transmission bands. The research will have far-reaching consequences for solving the wireless capacity bottleneck over the next 20 to 30 years and keeping the UK at the forefront of millimetre wave technology and innovation.

There are a number of ways in which the project plans to have a significant impact. The novel solutions developed on the project will impact on the project researchers, the industrial supporters and the wider communications industries in the UK. The main research beneficiaries will be all wireless technology users bringing significant societal benefits. The millimetre wave technology developed in the project will be deployed alongside current lower frequency communications systems (up to 6GHz) in smartphones, tablets, laptops, machine to machine devices, base stations, autonomous vehicles, on-body health monitoring devices, items in the home network from the internet of things, infrastructure monitoring and smart grids. The technology developed on this project would be expected to be operational within a 5 to 10-year timeframe. The defence sector will also benefit where fast transmission technologies for networked battlefields are emerging and novel digital processing techniques are being developed for radar systems. The project will enhance the UK's overall capability in advanced millimetre wave research, design and development. It will impact energy efficiency in mobile networks where energy consumption is expected to take a significant proportion of the national grid output.

We will have regular meetings and dialogue with our industrial supporters presenting our progress and results. An Advisory Board of industrialists will be established and meet every 6 months to observe progress, assist in steering the research programme and advise on exploitation. Thus, the industry will benefit from early exposure to our results. Our industrial supporters include original equipment manufacturers and major vendors and are therefore well placed to bring this technology to the mass market. In the defence sector, BAE SYSTEMS, HMGCC and Roke will be able to use the technology in battlefield communication systems and radars.

In addition to workshops and sessions organised through COMMNET2, Cambridge Wireless, EU-COST and major international conferences (see "Academic Impact") we will organise two open community networking workshops at 15 and 30 months targeting researchers in industry, academia and projects funded by this call, involving manufacturers, network operators and government regulators. Statutory spectrum policy/regulators such as OFCOM, ETSI and FCC will benefit from indicators of the capability of the technology to inform the path of future wireless infrastructure for regulation and standards.

Two named postdoctoral researchers will be funded on the project gaining valuable technical and professional experience from working in this important area of future technology. They will be trained in simulation methods and hardware design, manufacture and measurement. They will participate in University training of research funding, entrepreneurship, teaching and supervision skills to develop their careers. Four PhD students will be linked with the project, one funded by the Electronics and Electrical Engineering Department.

Our researchers will reach out to the wider community. The postdoctoral researchers will be encouraged to become STEM ambassadors to go into our schools and encourage children to get involved in science and engineering careers. Project researchers will also participate in the Sheffield University Science fair, one of the country's biggest events of its kind.

The investigators will be able to build on their reputations in this field through the recruitment of doctoral and masters level students. Experience and knowledge gained from the project will lead to future PhD projects and taught Masters programmes thereby enhancing teaching and learning opportunities at the University in a field of study where there is a huge shortage of engineers.