125 citations · 224 across the 16 of their papers we have counts for
16 papers
MiLAC-Aided Beamforming for MIMO Over-the-Air Computation
Yaru Wang, Deyou Zhang, Qingchao Li +2
Over-the-air computation (AirComp) enables low-latency wireless data aggregation, but its accuracy is limited by imperfect signal alignment over fading channels and receiver noise.…
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…
Space-Air-Ground Integrated Networks: Their Channel Model and Performance Analysis
Chao Zhang, Qingchao Li, Chao Xu +2
Given their extensive geographic coverage, low Earth orbit (LEO) satellites are envisioned to find their way into next-generation (6G) wireless communications. This paper explores…
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…
A Novel Time-Based Modulation Scheme in Time-Asynchronous Channels for Molecular Communications
Qingchao Li
In this paper, a novel time-based modulation scheme is proposed in the time-asynchronous channel for diffusion-based molecular communication systems with drift. Based on this modul…
The Crossover-Distance for ISI-Correcting Decoding of Convolutional Codes in Diffusion-Based Molecular Communications
Hui Li, Qingchao Li
In diffusion based molecular communication, the intersymbol interference (ISI) is an important reason for system performance degradation, which is caused by the random movement, ou…