15 papers · 1 filter
Transceiver Design for Cell-Free Unsourced Random Access
Mert Ozates, Mohammad Kazemi, Eduard Jorswieck +1
We propose a low-complexity, energy-efficient solution for cell-free unsourced random access (URA), in which multiple distributed access points are connected to a central processin…
Group-Connected Riemannian Manifold Optimization for Reciprocal BD-RIS
Marko Fidanovski, Thushar Venkataramanaiah, Eduard Jorswieck +1
Reconfigurable intelligent surfaces (RISs) provide a flexible means of engineering wireless propagation channels through configurable multiport scattering networks. Among their arc…
The manifold of unitary and symmetric matrices: characterization, Riemannian optimization and application to BD-RIS design
Ignacio Santamaria, Carlos Beltrán, Eduard Jorswieck +2
This paper proposes and analyzes Riemannian optimization algorithms on the manifold of unitary and symmetric matrices, denoted , which naturally models the scattering…
Optimal symmetric low-rank BD-RIS configuration maximizing the determinant of a MIMO link
Ignacio Santamaria, Mohammad Soleymani, Jesus Gutierrez +1
Beyond-diagonal reconfigurable intelligent surfaces (BD-RISs) significantly improve wireless performance by allowing tunable interconnections among elements, but their design in mu…
Riemannian optimization on the manifold of unitary and symmetric matrices with application to BD-RIS-assisted systems
Ignacio Santamaria, Mohammad Soleymani, Eduard Jorswieck +2
In this paper, we rigorously characterize for the first time the manifold of unitary and symmetric matrices, deriving its tangent space and its geodesics. The resulting parameteriz…
Spectral-Energy Efficiency Tradeoff of Nearly-Passive RIS in MIMO URLLC Downlink: Diagonal vs. Beyond Diagonal
Mohammad Soleymani, Alessio Zappone, Eduard Jorswieck +2
This paper investigates the spectral and energy efficiency (EE) tradeoff of nearly-passive (NP), both locally and globally NP (GNP), reconfigurable intelligent surface (RIS), consi…