Wireless communications via Cascaded-RIS aided systems
Ασύρματες επικοινωνίες υποβοηθούμενες με συστήματα διαδοχικών αναδιαμορφώσιμων έξυπνων επιφανειών
![Thumbnail](/xmlui/bitstream/handle/unipi/14693/Georgiou_mwe2002.pdf.jpg?sequence=4&isAllowed=y)
Master Thesis
Author
Γεωργίου, Αργύριος
Georgiou, Argyrios
Date
2022Advisor
Αλεξίου, ΑγγελικήAlexiou, Angeliki
View/ Open
Keywords
Wireless communications ; Reconfigurable Intelligent Surfaces (RIS) ; Cascaded ; MetasurfacesAbstract
The current research project examined the contribution of Reconfigurable Intelligent Surfaces (RISs) in wireless communication networks, by applying them on a cascaded double-RIS implementation. The conducted analytical and numerical study examined the performance of the cascaded-RIS system in several use case scenarios in terms of the receiver power at the User Equipment (UE). An analytical model that captures the performance of the double-RIS aided system was proposed, while the results were also verified by following a numerical calculation (discrete model). Focus was also given on the most critical performance parameters, such as the reflection coefficient of RIS elements, the phase-related operation features of the RIS, the transmitter gain, the beam footprint at the RIS plane, the distance between the UE and the RIS. The obtained results provide reasonable support that the under-examination double-RIS aided wireless communication system can establish a multi-hop cascaded LoS link which can effectively mitigate or even eliminate the adverse NLoS effects and, in general, can improve the system’s performance in terms of received power at the UE. In addition, it was found that phase-related RIS-operation features can further enhance the cascaded-RIS assisted system’s performance.