Advanced multiple access and reflective surfaces for 6G wireless networks
Thesis event information
Date and time of the thesis defence
Place of the thesis defence
IT 115, Linnanmaa campus
Topic of the dissertation
Advanced multiple access and reflective surfaces for 6G wireless networks
Doctoral candidate
Master of Science Farjam Karim
Faculty and unit
University of Oulu Graduate School, Faculty of Information Technology and Electrical Engineering, Communications Engineering
Subject of study
Communications Engineering
Opponent
Professor Olav Tirkkonen, Aalto University
Custos
Docent Nurul Huda Mahmood, University of Oulu
Advanced multiple access and reflective surfaces for 6G wireless networks
The development of sixth-generation (6G) wireless networks aims to provide fast, reliable, and energy-efficient communication for a large number of users and devices. Achieving these goals requires new ways of using limited radio resources and managing the interference and uncertainties that arise in wireless communication.
This thesis investigates advanced techniques for improving wireless communication, with particular focus on rate-splitting multiple access (RSMA) and reconfigurable intelligent surfaces (RIS). RSMA enables the messages of multiple users to be divided and transmitted flexibly using shared radio resources. The thesis studies both communication from a base station to users and from users to a base station. It also considers practical conditions in which information about the wireless channel is imperfect, interference cannot be completely removed, and communication hardware has non-ideal characteristics.
The thesis further investigates the transmission of short data packets, which is important for applications requiring fast and reliable communication. Wireless systems that can simultaneously transmit information and support energy harvesting are also studied. The performance of these systems is evaluated in terms of communication reliability, efficiency, and energy use under different practical conditions.
Another major focus is RIS-assisted wireless communication. RIS can be used to control the propagation of radio waves and potentially improve wireless connectivity. The thesis shows that thermal noise generated by passive RIS elements can have a significant impact on communication performance. This effect should therefore be considered when designing and evaluating practical RIS-based systems.
Overall, the results provide analytical insight into how future wireless communication systems can be designed to be more reliable, efficient, and energy-conscious while better accounting for practical operating conditions.
This thesis investigates advanced techniques for improving wireless communication, with particular focus on rate-splitting multiple access (RSMA) and reconfigurable intelligent surfaces (RIS). RSMA enables the messages of multiple users to be divided and transmitted flexibly using shared radio resources. The thesis studies both communication from a base station to users and from users to a base station. It also considers practical conditions in which information about the wireless channel is imperfect, interference cannot be completely removed, and communication hardware has non-ideal characteristics.
The thesis further investigates the transmission of short data packets, which is important for applications requiring fast and reliable communication. Wireless systems that can simultaneously transmit information and support energy harvesting are also studied. The performance of these systems is evaluated in terms of communication reliability, efficiency, and energy use under different practical conditions.
Another major focus is RIS-assisted wireless communication. RIS can be used to control the propagation of radio waves and potentially improve wireless connectivity. The thesis shows that thermal noise generated by passive RIS elements can have a significant impact on communication performance. This effect should therefore be considered when designing and evaluating practical RIS-based systems.
Overall, the results provide analytical insight into how future wireless communication systems can be designed to be more reliable, efficient, and energy-conscious while better accounting for practical operating conditions.
Created 14.9.2026 | Updated 15.9.2026