Dr Robert Zakrzewski - University of Bristol

The challenge

The challenge is to determine whether passive radio-frequency (RF) signals of opportunity can reveal useful information about internal building structures in complex environments. Existing approaches often assume known transmitters, stable signals, or simplified propagation conditions, whereas real environments involve heterogeneous and time-varying signals, multipath effects, and limited measurements, making the inference problem highly underdetermined. This project will investigate how auxiliary information, multiple sensing locations and times, and general geometric priors can improve structural inference. 

The research

Dr Robert Zakrzewski is investigating whether passive radio-frequency (RF) signals of opportunity can be used to infer coarse internal building structures without dedicated transmitters or intrusive sensing equipment. The work develops an underdetermined RF-based inference framework that combines measurements from multiple receiver locations and times with auxiliary information and general geometric priors. It will explore how signal type, frequency, sensing configuration, and available prior information affect the reliability of structural inference. The research aims to establish the practical limits of passive RF scene characterisation and determine whether features such as walls, partitions, and structural changes can be robustly detected in realistic environments, supporting future applications in infrastructure monitoring and disaster response.

The researcher

Dr Zakrzewski is a Senior Research Associate at the University of Bristol, specialising in RF and wireless communication systems, cybersecurity and resilience, and 3GPP system architectures across 4G–6G. His research combines RF sensing, Integrated Sensing and Communications (ISAC), anomaly detection, and machine learning to address security and resilience challenges in wireless systems. He holds a PhD in Electrical and Electronics Engineering from the University of Bristol and has industrial and academic experience, including systems engineering, and defence research. His motivation is to develop practical, non-intrusive RF sensing techniques that can provide useful information about complex environments.