3 citations · 14 across the 41 of their papers we have counts for
44 papers
One-Shot Beam Tracking for Stacked Intelligent Metasurfaces-Assisted LEO Broadcasting
Chandan Kumar Sheemar, Giovanni Iacovelli, Sourabh Solanki +2
This letter develops a physics-informed one-shot beam tracking method for stacked intelligent metasurface (SIM)-enabled low-Earth-orbit (LEO) links with users and an -layer…
Stacked Fluid Metasurfaces: Mutual-Coupling-Aware Modeling and Optimization
Giovanni Iacovelli, Chandan Kumar Sheemar, Symeon Chatzinotas
Stacked intelligent metasurfaces process the transmitted field layer by layer, and fluid antennas make the position of every radiator a design variable. Combined, they pack radiato…
Mutual-Coupling-Aware Movable and Fluid Antennas on Holographic Surfaces: A Wavenumber-Domain Circuit-Field Unification
Giovanni Iacovelli, Chandan Kumar Sheemar, Symeon Chatzinotas
Movable and fluid antenna systems turn antenna position into a design variable. At sub-wavelength spacings, however, their behavior is governed by mutual coupling, modeled today by…
Performance Analysis of RSMA-Enabled Bistatic ISAC in LEO Networks with Holographic Apertures and Fluid-Antenna Users
Wali Ullah Khan, Chandan Kumar Sheemar, Muhammad Adil +1
This paper develops an ergodic performance framework for rate-splitting multiple access (RSMA)-enabled bistatic integrated sensing and communication (ISAC) in a low-Earth-orbit (LE…
Terahertz Inter-Satellite Links: Motivation, Challenges and Opportunities
Chandan Kumar Sheemar, Wali Ullah Khan, Giovanni Iacovelli +5
Inter-satellite links (ISLs) are essential to the evolution of next-generation satellite constellations, providing the foundation for low-latency, resilient, and globally scalable…
Energy Efficient Multi-User Beamforming and 3D Position Optimization for SIM-Assisted UAVs
Chandan Kumar Sheemar, Giovanni Iacovelli, Sourabh Solanki +3
This paper studies energy-efficient downlink multi-user transmissions with unmanned aerial vehicle (UAV) communication systems equipped with stacked intelligent metasurfaces (SIM),…
Extremely Large Beyond-Diagonal RIS: Low-Rank Modal Optimization for Near-Field Communications
Giovanni Iacovelli, Chandan Kumar Sheemar, Eva Lagunas +1
Beyond-diagonal reconfigurable intelligent surfaces (BD-RIS) achieve their best performance when fully connected, at the price of an optimization and hardware burden that grows qua…
Wavenumber-Domain Virtual Arrays for Holographic Near-Field Localization
Giovanni Iacovelli, Chandan Kumar Sheemar, Symeon Chatzinotas
Monostatic localization of multiple point targets is studied for a holographic aperture operated through wavenumber-domain modes. A specular-point condition delimits the validity o…
Stacked Intelligent Metasurfaces Assisted UAV Communications
Chandan Kumar Sheemar, Giovanni Iacovelli, Sourabh Solanki +2
In this paper, we investigate an unmanned aerial vehicle (UAV) communication system assisted by stacked intelligent metasurfaces (SIMs), which enable programmable wave-domain signa…
Low-Complexity Learning-Based Beamforming for Ultra-Massive MIMO THz Communications
Sourabh Solanki, Abuzar Babikir Mohammad Adam, Chandan Kumar Sheemar +4
Terahertz (THz) communications have emerged as a key technology for escalating data rates in future generation wireless networks. However, severe propagation losses at THz frequenc…
STAR Beyond Diagonal RISs with Amplification: Modeling and Optimization
Chandan Kumar Sheemar, Giovanni Iacovelli, Wali Ullah Khan +3
This paper develops a physically consistent signal model with hardware constraints for a simultaneous transmitting and reflecting beyond-diagonal RIS (STAR BD-RIS) endowed with per…
A Survey on Stacked Intelligent Metasurfaces: Fundamentals, Recent Advances, and Challenges
Chandan Kumar Sheemar, Wali Ullah Khan, Sourabh Solanki +2
Reconfigurable intelligent surfaces (RISs) enable programmable control of wireless propagation. Beyond environmental deployments, integrating metasurfaces at the antenna front end…
A Survey on STAR-RIS Enabled Joint Communications and Sensing: Fundamentals, Recent Advances and Research Challenges
Wali Ullah Khan, Chandan Kumar Sheemar, Syed Tariq Shah +2
The joint communications and sensing (JCAS) paradigm is envisioned as a core capability of sixth-generation (6G) wireless networks, enabling the integration of data communication a…
Multilayer Non-Terrestrial Networks with Spectrum Access aided by Beyond-Diagonal RIS
Wali Ullah Khan, Chandan Kumar Sheemar, Eva Lagunas +4
In this work, we study a multi-user NTN in which a satellite serves as the primary network and a high-altitude platform station (HAPS) operates as the secondary network, acting as…
Joint Communications, Sensing, and Positioning in 6G Multi-Functional Satellite Systems: Survey and Open Challenges
Chandan Kumar Sheemar, Jorge Querol, Wali Ullah Khan +7
Satellite systems are expected to be a cornerstone of sixth-generation (6G) networks, providing ubiquitous coverage and supporting a wide range of services across communications, s…
Swarm Intelligence Optimization of Multi-RIS Aided MmWave Beamspace MIMO
Zaid Abdullah, Mario R. Camana, Abuzar B. M. Adam +3
We investigate the performance of a multiple reconfigurable intelligence surface (RIS)-aided millimeter wave (mmWave) beamspace multiple-input multiple-output (MIMO) system with mu…
Multi-Active RIS-Assisted THz Cell-Free Systems: Spectral and Energy Efficiency Tradeoff
Mario R. Camana, Zaid Abdullah, Carla E. Garcia +3
Reconfigurable intelligent surfaces (RISs) and cell-free massive multiple-input multiple-output (CF-mMIMO) are effective solutions for mitigating large path loss and inter-cell int…
Survey on Beyond Diagonal RIS Enabled 6G Wireless Networks: Fundamentals, Recent Advances, and Challenges
Wali Ullah Khan, Manzoor Ahmed, Chandan Kumar Sheemar +7
Beyond Diagonal Reconfigurable Intelligent Surfaces (BD-RIS) represent a groundbreaking innovation in sixth-generation (6G) wireless networks, enabling unprecedented control over w…
RIS-based Physical Layer Security for Integrated Sensing and Communication: A Comprehensive Survey
Yongxiao Li, Feroz Khan, Manzoor Ahmed +5
Integrated Sensing and Communication (ISAC) is a crucial component of future wireless networks, enabling seamless integration of Communication and Sensing (C\&S) functionalities. H…
Minimum Mean Squared Error Holographic Beamforming for Sum-Rate Maximization
Chandan Kumar Sheemar, Wali Ullah Khan, George C. Alexandropoulos +2
This paper studies the problem of hybrid holographic beamforming for sum-rate maximization in a communication system assisted by a reconfigurable holographic surface. Existing meth…
Enhancing Physical Layer Security in Cognitive Radio-Enabled NTNs with Beyond Diagonal RIS
Wali Ullah Khan, Chandan Kumar Sheemar, Eva Lagunas +1
Beyond diagonal reconfigurable intelligent surfaces (BD-RIS) have emerged as a transformative technology for enhancing wireless communication by intelligently manipulating the prop…
Beyond Diagonal RIS Enhanced Cognitive Radio Enabled Multilayer Non-Terrestrial Networks
Wali Ullah Khan, Chandan Kumar Sheemar, Eva Lagunas +1
Beyond diagonal reconfigurable intelligent surfaces (BD-RIS) have emerged as a transformative technology for enhancing wireless communication by intelligently manipulating the prop…
Secrecy Rate Maximization for 6G Reconfigurable Holographic Surfaces Assisted Systems
Chandan Kumar Sheemar, Wali Ullah Khan, Marco di Renzo +3
Reconfigurable holographic surfaces (RHS) have emerged as a transformative material technology, enabling dynamic control of electromagnetic waves to generate versatile holographic…
Joint Beamforming and 3D Location Optimization for Multi-User Holographic UAV Communications
Chandan Kumar Sheemar, Asad Mahmood, Christo Kurisummoottil Thomas +4
This paper pioneers the field of multi-user holographic unmanned aerial vehicle (UAV) communications, laying a solid foundation for future innovations in next-generation aerial wir…