Researchers from TITAN partner Loughborough University are pioneering new methods to enhance Non-Terrestrial Networks (NTNs) through the integration of Orthogonal Time Frequency Space (OTFS) modulation. Traditional modulation techniques like OFDM…
Researchers from TITAN partner Loughborough University are pioneering new methods to enhance Non-Terrestrial Networks (NTNs) through the integration of Orthogonal Time Frequency Space (OTFS) modulation. Traditional modulation techniques like OFDM face serious challenges in satellite communications due to high mobility, long delays, and significant Doppler effects. OTFS, however, offers robustness against these limitations, making it a strong candidate for future NTN and satellite-based systems. This research pushes OTFS forward by improving model accuracy and exploring synergies with emerging technologies.
A key advancement of this project lies in the exploration of spatial modulation (SM) integrated with OTFS. The team demonstrated that SM-OTFS significantly boosts data throughput and showed, for the first time, how imperfections in channel estimation can affect system performance. This insight provides a much-needed reference for industry, helping engineers account for real-world challenges when deploying OTFS-based satellite communication systems. The study also analyses multiple demodulation schemes for SM-OTFS, revealing that the best-performing method varies depending on the channel conditions—an important finding for adaptive system design.
In parallel, the researchers have investigated how OTFS can be paired with fluid antenna systems (FAS), a novel antenna technology designed to be both space- and energy-efficient. This pairing is particularly well-suited for small IoT devices or mobile terminals operating in remote or underserved areas, where power sources are limited and robust connectivity is essential. By validating the compatibility and effectiveness of FAS-OTFS, the research opens the door to highly efficient communication systems that can thrive even at the edge of the network.
This research has been driven by collaboration across leading institutions. Professor Kit Wong of UCL has been a key partner on the FAS-OTFS investigations, while Professor Lajos Hanzo at the University of Southampton has contributed extensively to the broader OTFS analysis. These academic efforts are part of a larger initiative to push NTNs beyond the limitations of conventional terrestrial infrastructure.
Looking ahead, the team aims to develop adaptive algorithms that can automatically choose the optimal modulation and demodulation techniques based on user demands and environmental conditions. Additional research will expand the modulation schemes considered in FAS-OTFS models and integrate machine learning to enable smarter, more responsive systems, such as using neural networks for signal decoding or port selection in FAS.
As NTNs emerge as a cornerstone of future global connectivity, this work lays the foundation for more resilient and efficient satellite communication systems. By advancing both theory and application, the team is ensuring that enabling technologies like OTFS and FAS can meet the real-world demands of a hyper-connected world.
The research is a part of TITAN Lighthouse Project 5 (LP5): Non-Terrestrial Network Design and Optimisation. The project explores the development and enhancement of communication systems that operate beyond traditional ground-based infrastructure, such as satellite and high-altitude platform networks.
TITAN is part of the Federated Telecoms Hubs (FTH) alongside CHEDDAR, HASC, and JOINER. Together, we conduct world-leading R&D and create a new knowledge-sharing framework, roadmap technology, develop skills, and engage with standards while instilling a commercialisation-focused mindset across academia.
If you have any questions about the research discussed in this article, please contact titan-enquiries@eng.cam.ac.uk.
