@article{10902/29771,
year = {2023},
month = {7},
url = {https://hdl.handle.net/10902/29771},
abstract = {Reconfigurable intelligent surface (RIS) architectures not limited to diagonal phase shift matrices have recently been considered to increase their flexibility in shaping the wireless channel. One of these beyond-diagonal RIS or BD-RIS architectures leads to a unitary and symmetric RIS matrix. In this letter, we consider the problem of maximizing the signal-to-noise ratio (SNR) in single and multiple antenna links assisted by a BD-RIS. The Max-SNR problem admits a closed-form solution based on the Takagi factorization of a certain complex and symmetric matrix. This allows us to solve the max-SNR problem for SISO, SIMO, and MISO channels.},
organization = {The work of Ignacio Santamaria was supported by the Ministerio de Ciencia e Innovación and AEI (10.13039/501100011033), under Grant PID2019-104958RB C43 (ADELE). The work of Eduard Jorswieck was supported by the Federal Ministry of Education and Research (BMBF, Germany) through the Program of
Souverän. Digital. Vernetzt. joint Project 6G-RIC, under Grants 16KISK020K and 16KISK031.},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
publisher = {IEEE Signal Processing Letters, 2023, 30, 923-926},
title = {SNR maximization in beyond diagonal RIS-assisted single and multiple antenna links},
author = {Santamaría Caballero, Luis Ignacio and Soleymani, Mohammad and Jorswieck, Eduard and Gutiérrez Terán, Jesús},
}