I may not always have prepared thesis topics available. Please feel free to reach out if you are interested in working on a thesis within any of my research areas.

Voraussetzungen

The main objective is to understand the interplay between the sensing capabilities and the communications capabilities of a communications system, which is a major part of the upcoming 6G standard known as Integrated Sensing and Communications (ISAC) (also known as Joint Communications and Sensing (JCAS)). To better understand the pros and cons, there are several tasks that need to be undertaken: 

• Learn the basics of delay-Doppler domain representation of doubly dispersive channels as well as the meaning of the ambiguity function of a transmit waveform.
• Understand how an OFDM system might be used for target detection (radar application)?
• How does the system change when we add communications signals?
  
  
• Two main scenarios:
    
• Monostatic sensing and bistatic sensing.
• Synchronization and carrier frequency offset seem to be one of the challenges, and the goal of the thesis is to better understand these problems and possibly validate them with real data.
• Simulate the whole system using Python and report relevant figures of merit.
•  Probability of detection, probability of misdetection, probability of false detection as well as bit error rates (BER) for the communications part and mean squared error for the detection parameters. This task requires getting used to working in Python.

Intelligent reflecting surfaces (IRS) have been considered a novel technology for 6G wireless communications. They allow to have a reliable transmission in scenarios where the LOS communication is not available (e.g, in case of blockage) [1]. They also allow to perform Integrated sensing and communication [2].

A very important scenario in which the IRS can be useful is the Multi-user one, where a BS is communicating with multiple UEs. In this case the IRS can be used in order to perform channel estimation or to improve the communication quality by increasing the Beamforming quality [3-4-5].

The task of the student is to make a literature review based on this case scenarios, in order to give an overview on the pros and cons of those technologies. The student can focus either on the channel estimation side or the beamforming one.

[1] He, Jiguang, et al. "Adaptive beamforming design for mmWave RIS-aided joint localization and communication." 2020 IEEE Wireless Communications and Networking Conference Workshops (WCNCW). IEEE, 2020.

[2] Muhr, F., Zaniboni, L., Dehkordi, S. K., Pedraza, F., & Caire, G. (2023, May). Beam Alignment with an Intelligent Reflecting Surface for Integrated Sensing and Communication. In 2023 IEEE International Conference on Communications Workshops (ICC Workshops) (pp. 679-684). IEEE.   [3] Wei, Li, et al. "Channel estimation for RIS-empowered multi-user MISO wireless communications." IEEE Transactions on Communications 69.6 (2021): 4144-4157.   [4] Verde, Francesco, Donatella Darsena, and Vincenzo Galdi. "Rapidly time-varying reconfigurable intelligent surfaces for downlink multiuser transmissions." IEEE Transactions on Communications (2024).   [5] Rafieifar, Anahid, et al. "Secure beamforming in multi-user multi-IRS millimeter wave systems." IEEE Transactions on Wireless Communications (2023).