125 citations · 234 across the 21 of their papers we have counts for
13 papers · 1 filter
Stacked Intelligent Metasurface-Based Transceiver Design for Near-Field Wideband Systems
Qingchao Li, Mohammed El-Hajjar, Chao Xu +3
Intelligent metasurfaces may be harnessed for realizing efficient holographic multiple-input and multiple-output (MIMO) systems, at a low hardware-cost and high energy-efficiency.…
Low-Complexity Channel Estimation for RIS-Assisted Multi-User Wireless Communications
Qingchao Li, Mohammed El-Hajjar, Ibrahim Hemadeh +2
Reconfigurable intelligent surfaces (RISs) are eminently suitable for improving the reliability of wireless communications by jointly designing the active beamforming at the base s…
Holographic Metasurface-Based Beamforming for Multi-Altitude LEO Satellite Networks
Qingchao Li, Mohammed El-Hajjar, Kaijun Cao +3
Low Earth Orbit (LEO) satellite networks are capable of improving the global Internet service coverage. In this context, we propose a hybrid beamforming design for holographic meta…
Stacked Intelligent Metasurfaces for Holographic MIMO Aided Cell-Free Networks
Qingchao Li, Mohammed El-Hajjar, Chao Xu +3
Large-scale multiple-input and multiple-output (MIMO) systems are capable of achieving high date rate. However, given the high hardware cost and excessive power consumption of mass…
Ergodic Spectral Efficiency Analysis of Intelligent Omni-Surface Aided Systems Suffering From Imperfect CSI and Hardware Impairments
Qingchao Li, Mohammed El-Hajjar, Lajos Hanzo
In contrast to the conventional reconfigurable intelligent surfaces (RIS), intelligent omni-surfaces (IOS) are capable of full-space coverage of smart radio environments by simulta…
Performance Analysis of Reconfigurable Holographic Surfaces in the Near-Field Scenario of Cell-Free Networks Under Hardware Impairments
Qingchao Li, Mohammed El-Hajjar, Yanshi Sun +1
We propose a hybrid beamforming architecture for near-field reconfigurable holographic surfaces (RHS) harnessed in cell-free networks. Specifically, the holographic beamformer of e…
Energy-Efficient Reconfigurable Holographic Surfaces Operating in the Presence of Realistic Hardware Impairments
Qingchao Li, Mohammed El-Hajjar, Yanshi Sun +3
Reconfigurable holographic surfaces (RHSs) constitute a promising technique of supporting energy-efficient communications. In this paper, we formulate the energy efficiency maximiz…
Achievable Rate Analysis of Intelligent Omni-Surface Assisted NOMA Holographic MIMO Systems
Qingchao Li, Mohammed El-Hajjar, Yanshi Sun +4
An intelligent omni-surface (IOS) assisted holographic multiple-input and multiple-output architecture is conceived for full-space coverage at a low energy consumption.…
Achievable Rate Analysis of the STAR-RIS Aided NOMA Uplink in the Face of Imperfect CSI and Hardware Impairments
Qingchao Li, Mohammed El-Hajjar, Yanshi Sun +4
Reconfigurable intelligent surfaces (RIS) are capable of beneficially ameliorating the propagation environment by appropriately controlling the passive reflecting elements. To exte…
Reconfigurable Intelligent Surface Aided Amplitude- and Phase-Modulated Downlink Transmission
Qingchao Li, Mohammed El-Hajjar, Ibrahim Hemadeh +3
New reconfigurable intelligent surface (RIS) based amplitude and phase modulation schemes are proposed as an evolution how the phase-only modulation schemes available in the litera…
Performance Analysis of Active RIS-aided Systems in the Face of Imperfect CSI and Phase Shift Noise
Qingchao Li, Mohammed El-Hajjar, Ibrahim Hemadeh +3
The linear minimal mean square error (LMMSE) estimator for active reconfigurable intelligent surface (RIS)-aided wireless systems is formulated. Furthermore, based on the moment-ma…
Reconfigurable Intelligent Surfaces Relying on Non-Diagonal Phase Shift Matrices
Qingchao Li, Mohammed El-Hajjar, Ibrahim Hemadeh +4
Reconfigurable intelligent surfaces (RIS) have been actively researched as a potential technique for future wireless communications, which intelligently ameliorate the signal propa…
Analysis of Network Coding Schemes for Differential Chaos Shift Keying Communication System
Georges Kaddoum, Mohammed El-Hajjar
In this paper we design network coding schemes for Differential Chaos Shift Keying (DCSK) modulation. In this work, non-coherent chaos-based communication system is used due to its…