Quantum key distribution with 5G technology integration

About the project

The objective of this project is to integrate quantum communication into emerging wireless networks, paving the way for a global quantum network in time for 6G.

Continuous-variable QKD (CV-QKD) modulates its information onto the phase or amplitude of the electromagnetic wave. This enables quantum-secured applications such as banking and healthcare to be delivered using off-the-shelf wireless transceivers.

Nonetheless, the current wireless CV-QKD systems face two significant limitations:

To mitigate these challenges, on the one hand, 5G-compliant error correction codes will be designed for enhancing CV-QKD’s robustness against channel impairments. On the other hand, leveraging the principal waveform of orthogonal frequency division multiplexing (OFDM) in 5G, the secret key rate is expected to increase with the number of OFDM subcarriers, thereby optimizing wireless spectrum access.

This frontier research will address key national strategies: the National Quantum Strategy, the EPSRC Strategic Delivery Plan 2022-2025, the Telecommunications (Security) Act 2021 and National Cyber Strategy 2022, and the Net Zero Strategy.

This project will be supervised by Dr Chao Xu, the first researcher from the University of Southampton to achieve the highest score 100/100 in the EU’s Marie Sklodowska-Curie Actions (MSCA) fellowship proposal evaluation.

This project will provide a unique cross-disciplinary training to an aspiring PhD student. The PhD student and supervisors will also intensively collaborate with industrial collaborators. Moreover, the knowledge gleaned by this project will be transferred to students through teaching by the supervisors, which will inspire more Southampton students to quantum research.

• firstly, transmission distance is constrained by both atmospheric turbulence and the multipath effect in electromagnetic wave propagation;
• secondly, the generation rate of secret key is orders of magnitude lower than the classical communication data rate.

Dr Chao Xu

• space-air-ground integrated networks,
• reconfigurable intelligent surface,
• machine learning,

Entry requirements

You must have an undergraduate degree (at least UK 2:1 honours degree) or its international equivalent .

Fees and funding

For candidates looking to complete a PhD or EngD full-time we offer an enhanced tax-free stipend of up to £30,000 per year, along with a substantial budget for research, travel, and centre activities.

CISDnS is committed to promoting equality, diversity and inclusivity. We welcome all applicants regardless of their gender, ethnicity, disability, sexual orientation or age, and will give full consideration to applicants seeking flexible working patterns and those who have taken a career break or are transitioning into a new role. The University has a generous maternity policy, onsite childcare facilities, and offers a range of benefits to help ensure employees’ well-being and work-life balance.

We are pleased to announce that for 2027/28 entry, specific Centres for Doctoral Training (CDTs) at the University of Southampton have been selected to be part of a pilot programme of funding for UK doctoral candidates launched by the Department for Science, Innovation and Technology (DSIT) and UK Research and Innovation (UKRI). Now managed by the Department for Digital, Culture Media and Sport (DCMS), the funding is delivered through a strand of government’s new TechFirst skills programme. TechFirst will fund nationally, a stipend uplift for at least 500 domestic (UK only) doctoral students in priority technology areas over the next four years, strengthening the UK’s innovation pipeline and building a more inclusive, resilient and high-impact research ecosystem.

How to apply

Apply now

Please apply via the online portal and select:

Applications should include:

• Academic year: 2027/28
• If you will be full time or part time
• Faculty: Engineering and Physical Sciences
• Search for PhD Quantum Tech Eng
• Select either PhD or EngD – if you are unsure, select PhD
• Add the name of the supervisor in section 2 of the application.
• your CV (resumé)
• 2 academic references
• degree transcripts and certificates to date

Faculty of Engineering and Physical Sciences

For questions about applying, email our Doctoral College (doctoralcollege-admissions@soton.ac.uk) .

Project leader

For an initial conversation, email Dr Chao Xu (cx1g08@soton.ac.uk) .

Research areas