Prof. Mathias Fink / Wave Control for Wireless Communications скачать в хорошем качестве

Prof. Mathias Fink / Wave Control for Wireless Communications

Prof. Mathias Fink / Wave Control for Wireless Communications: From Time-Reversal Processing to Reconfigurable Intelligent Metasurfaces TII Metamaterials and Applications Seminar 2021 – Mathias Fink - Langevin Institute In this talk, I will show how the works performed at Langevin Institute have led to the seminal concept behind large reconfigurable intelligent surfaces (RIS) that is currently a topic of great interest in the wireless communication community and that is proposed as a new paradigm for the sixth generation (6G) of communication networks. Starting with the first demonstrations of ultrasonic “time-reversal mirrors” focusing in complex media in the early nineties, I will underline how these ideas were first used for underwater acoustic communications and were transposed later, for electromagnetic waves, into the concept of massive MIMO for the 5G communication networks to optimize channel diversity. Compared to these techniques that need multiple antenna array, I will explain how we proposed, 9 years ago, another approach using tunable metasurfaces to obtain with a limited number of transmitters the best communication performance. The main idea is to replace the numerous transmitting antennas, used in massive MIMO, by a smart modification of the wireless environment by physically shaping the propagation medium to achieve optimal focusing and channel diversity. Smart mirrors placed inside any wireless environment can tune the medium complexity to obtain the best communication performance. I will show how the optimization of these metasurfaces results from the generalization of the “time reversal mirror” concept to the one of the product of different time-reversal mirrors associated with each transmitters and receivers.