20 papers
Confidence-Guided Adaptive Beam Selection for Vision-Aided Beam Tracking in mmWave Systems
Sohani Munteha Hiam, Mohammad Soleymani, Rafael F. Schaefer
Vision-aided beam tracking reduces mmWave beam-training overhead by predicting beam indices from camera observations. Fixed top- selection, however, assigns the same candidate b…
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…
RIS-Aided RSMA Improves the Latency vs. Energy Trade-off in the Finite Block Length MIMO Downlink
Mohammad Soleymani, Bruno Clerckx, Robert Schober +1
We simultaneously minimize the latency and improve energy efficiency (EE) of the multi-user multiple-input multiple-output (MU-MIMO) rate splitting multiple access (RSMA) downlink,…
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…
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…
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…
The Wideband Analysis of the Impact of I/Q Imbalance on THz Communication
Dogus Can Sevdiren, Aydin Sezgin, Mohammad Soleymani
The terahertz (THz) band is a promising solution to the increasing data traffic demands of future wireless networks. However, developing transceivers for THz communication is a com…
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…
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…
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…
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…
Maximizing Spectral and Energy Efficiency in Multi-user MIMO OFDM Systems with RIS and Hardware Impairment
Mohammad Soleymani, Ignacio Santamaria, Aydin Sezgin +1
An emerging technology to enhance the spectral efficiency (SE) and energy efficiency (EE) of wireless communication systems is reconfigurable intelligent surface (RIS), which is sh…
Maximization of minimum rate in MIMO OFDM RIS-assisted Broadcast Channels
Mohammad Soleymani, Ignacio Santamaria, Aydin Sezgin +1
Reconfigurable intelligent surface (RIS) is a promising technology to enhance the spectral efficiency of wireless communication systems. By optimizing the RIS elements, the perform…