Stacked Intelligent Metasurface (SIM) for Orthogonal Time Frequency Space (OTFS)

Supervisory Team: Dr Chao Xu

This project will explore the combination of Stacked Intelligent Metasurfaces (SIM) and Orthogonal Time Frequency Space (OTFS) in the context of Space-Air-Ground Integrated Network (SAGIN) applications.

Stacked Intelligent Metasurfaces (SIM) are composed of multiple layers of programmable meta-atoms that can dynamically manipulate electromagnetic (EM) waves as they propagate through them. Each meta-atom acts as a reconfigurable artificial neuron with tunable weights—drawing a strong parallel with Deep Neural Networks (DNNs), but Graphics Processing Units (GPUs) are no longer required. This architecture enables real-time wireless computing such as beamforming and Fourier transform to be performed at the speed of light, as EM wave propagates through multiple layers of metasurfaces.

Space-Air-Ground Integrated Network (SAGIN) is a promising candidate for providing ubiquitous coverage in 6G. However, SAGIN still faces a dual challenge: longer communication ranges and higher vehicle speeds lead to increased delay spreads and Doppler shifts, which result in inter-symbol interference (in the time domain) and inter-carrier interference (in the frequency domain).

Orthogonal Time Frequency Space (OTFS) overcomes these issues by transforming doubly dispersive channels in the time-frequency domain into quasi-static representations in the delay-Doppler (DD) domain, making it highly promising for SAGINs.

This project will explore the combination of SIM and OTFS in the context of SAGIN applications.

Programmable beamforming, waveform generation and detection, Integrated Communication and Sensing (ISAC) functionalities will be explored.

DNN solutions that can backward reprogram SIM will also be investigated.

This project will be supervised by Dr Chao Xu, who’s 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.

Entry Requirements: A UK 2:1 honours degree, or its international equivalent.

Fees and Funding: We offer a range of funding opportunities for both UK and international students. Horizon Europe fee waivers automatically cover the difference between overseas and UK fees for qualifying students.

Competition-based Presidential Bursaries from the University cover the difference between overseas and UK fees for top-ranked applicants.

Funding will be awarded on a rolling basis, so apply early for the best opportunity to be considered.

For more information, please visit our postgraduate research funding pages.

How to Apply: You need to

• choose programme type (Research), 2026/27, Faculty of Engineering and Physical Sciences
• select Full time or Part time
• search for programme PhD Electronic & Electrical Engineering (7092)
• add name of the supervisor in section 2 of the application

Applications should include:

• research proposal
• your CV (resumé)
• 2 academic references
• degree transcripts and certificates to date
• English language qualification (if applicable)