24 papers
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…
Scalable Design for RIS-Assisted Multi-User Downlink System Empowered by RSMA under Partial CSI
Yifan Fang, Bile Peng, Yingyang Chen +3
In large-scale reconfigurable intelligent surface (RIS) communication systems, the precise acquisition of channel state information (CSI) is challenging. Consider a practical RIS c…
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…
DRL-Based Spectrum Sharing for RIS-Aided Local High-Quality Wireless Networks
Hamid Reza Hashempour, Mina Khadem, Eduard A. Jorswieck +1
This paper investigates a smart spectrum-sharing framework for reconfigurable intelligent surface (RIS)-aided local high-quality wireless networks (LHQWNs) within a mobile network…
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…
Energy-Efficient Power Control in Single-User M-MIMO-OFDM System with PA Nonlinearity
Siddarth Marwaha, Pawel Kryszkiewicz, Eduard A. Jorswieck
Although multiple works have proposed energy-efficient resource allocation schemes for Massive Multiple-Input Multiple-Output (M-MIMO) system, most approaches overlook the potentia…
STAR-RIS-aided RSMA for the URLLC multi-user MIMO Downlink
Mohammad Soleymani, Ignacio Santamaria, Eduard Jorswieck +2
Rate splitting multiple access (RSMA) is intrinsically amalgamated with simultaneously transmitting and reflecting (STAR) reconfigurable intelligent surfaces (RIS) to enhance energ…
Beamforming Tradeoff for Sensing and Communication in Cell-Free MIMO
Xi Ding, Luca Kunz, E. Jorswieck
This paper studies optimal joint beamforming (BF) for joint sensing and communication (JSAC) in small-scale cell-free MIMO (CF-MIMO) systems. While prior works have explored JSAC o…
Energy Efficiency Optimization of Finite Block Length STAR-RIS-aided MU-MIMO Broadcast Channels
Mohammad Soleymani, Ignacio Santamaria, Eduard Jorswieck +2
Energy-efficient designs are proposed for multi-user (MU) multiple-input multiple-output (MIMO) broadcast channels (BC), assisted by simultaneously transmitting and reflecting (STA…
Rate Analysis and Optimization of LoS Beyond Diagonal RIS-assisted MIMO Systems
Ignacio Santamaria, Jesus Gutierrez, Mohammad Soleymani +1
In this letter, we derive an expression for the achievable rate in a multiple-input multiple-output (MIMO) system assisted by a beyond-diagonal reconfigurable intelligent surface (…
Interference Minimization in Beyond-Diagonal RIS-assisted MIMO Interference Channels
Ignacio Santamaria, Mohammad Soleymani, Eduard Jorswieck +1
This paper proposes a two-stage approach for passive and active beamforming in multiple-input multiple-output (MIMO) interference channels (ICs) assisted by a beyond-diagonal recon…
A Framework for Fractional Matrix Programming Problems with Applications in FBL MU-MIMO
Mohammad Soleymani, Eduard Jorswieck, Robert Schober +1
An efficient framework is conceived for fractional matrix programming (FMP) optimization problems (OPs) namely for minimization and maximization. In each generic OP, either the obj…
ODMA-Based Cell-Free Unsourced Random Access with Successive Interference Cancellation
Mert Ozates, Mohammad Kazemi, Eduard Jorswieck +1
We consider the unsourced random access problem with multiple receivers and propose a cell-free type solution for that. In our proposed scheme, the active users transmit their sign…
URLLC Networks enabled by STAR-RIS, Rate Splitting, and Multiple Antennas
Eduard Jorswieck, Mohammad Soleymani, Ignacio Santamaria +1
The challenges in dense ultra-reliable low-latency communication networks to deliver the required service to multiple devices are addressed by three main technologies: multiple ant…
Rate Splitting Multiple Access for RIS-aided URLLC MIMO Broadcast Channels
Mohammad Soleymani, Ignacio Santamaria, Eduard Jorswieck +3
The performance of modern wireless communication systems is typically limited by interference. The impact of interference can be even more severe in ultra-reliable and low-latency…
Rate Region of RIS-Aided URLLC Broadcast Channels: Diagonal versus Beyond Diagonal Globally Passive RIS
Mohammad Soleymani, Alessio Zappone, Eduard Jorswieck +2
We analyze the finite-block-length rate region of wireless systems aided by reconfigurable intelligent surfaces (RISs), employing treating interference as noise. We consider three…
Energy Efficiency Comparison of RIS Architectures in MISO Broadcast Channels
Mohammad Soleymani, Ignacio Santamaria, Eduard Jorswieck +2
In this paper, we develop energy-efficient schemes for multi-user multiple-input single-output (MISO) broadcast channels (BCs), assisted by reconfigurable intelligent surfaces (RIS…
Distributed Signal Processing for Extremely Large-Scale Antenna Array Systems: State-of-the-Art and Future Directions
Yanqing Xu, Erik G. Larsson, Eduard A. Jorswieck +3
Extremely large-scale antenna arrays (ELAA) play a critical role in enabling the functionalities of next generation wireless communication systems. However, as the number of antenn…
MIMO Capacity Maximization with Beyond-Diagonal RIS
Ignacio Santamaria, Mohammad Soleymani, Eduard Jorswieck +1
This paper addresses the problem of maximizing the capacity of a multiple-input multiple-output (MIMO) link assisted by a beyond-diagonal reconfigurable intelligent surface (BD-RIS…
SLIPT in Joint Dimming Multi-LED OWC Systems with Rate Splitting Multiple Access
Sepideh Javadi, Sajad Faramarzi, Farshad Zeinali +5
Optical wireless communication (OWC) systems with multiple light-emitting diodes (LEDs) have recently been explored to support energy-limited devices via simultaneous lightwave inf…
Optimization of the Downlink Spectral- and Energy-Efficiency of RIS-aided Multi-user URLLC MIMO Systems
Mohammad Soleymani, Ignacio Santamaria, Eduard Jorswieck +2
Modern wireless communication systems are expected to provide improved latency and reliability. To meet these expectations, a short packet length is needed, which makes the first-o…