258 citations · 1.2k across the 44 of their papers we have counts for
50 papers
Boosting Spectral Efficiency via Spatial Path Index Modulation in RIS-Aided mMIMO
Ahmet M. Elbir, Abdulkadir Celik, Asmaa Abdallah +1
Next generation wireless networks focus on improving spectral efficiency (SE) while reducing power consumption and hardware cost. Reconfigurable intelligent surfaces (RISs) offer a…
Comprehensive Analysis of Behavioral Hardware Impairments in Cell-Free Massive MIMO-OFDM Uplink: Centralized Operation
Özlem Tuğfe Demir, Muhammed Selman Somuncu, Ahmet M. Elbir +1
Cell-free massive MIMO is a key 6G technology, offering superior spectral and energy efficiency. However, its dense deployment of low-cost access points (APs) makes hardware impair…
A New Wireless Image Transmission System Using Code Index Modulation and Image Enhancement for High-Rate Next Generation Networks
Burak Ahmet Ozden, Erdogan Aydin, Ahmet Elbir +1
With the development of wireless network technologies, the wireless image transmission area has become prominent. The need for high resolution, data traffic density, widespread use…
Hybrid Beamforming for Integrated Sensing and Communications With Low Resolution DACs
Ahmet M. Elbir, Abdulkadir Celik, Ahmed M. Eltawil
Integrated sensing and communications (ISAC) has emerged as a means to efficiently utilize spectrum and thereby save cost and power. At the higher end of the spectrum, ISAC systems…
Near-Field Signal Processing: Unleashing the Power of Proximity
Ahmet M. Elbir, Özlem Tuğfe Demir, Kumar Vijay Mishra +2
After nearly a century of specialized applications in optics, remote sensing, and acoustics, the near-field (NF) electromagnetic propagation zone is experiencing a resurgence in re…
The Curse of Beam-Squint in ISAC: Causes, Implications, and Mitigation Strategies
Ahmet M. Elbir, Kumar Vijay Mishra, Abdulkadir Celik +1
Integrated sensing and communications (ISAC) has emerged as a means to efficiently utilize spectrum and thereby save cost and power. At the higher end of the spectrum, ISAC systems…
Index Modulation for Integrated Sensing and Communications: A Signal Processing Perspective
Ahmet M. Elbir, Abdulkadir Celik, Ahmed M. Eltawil +1
A joint design of both sensing and communication can lead to substantial enhancement for both subsystems in terms of size, cost as well as spectrum and hardware efficiency. In the…
Cooperative RIS and STAR-RIS assisted mMIMO Communication: Analysis and Optimization
Anastasios Papazafeiropoulos, Ahmet M. Elbir, Pandelis Kourtessis +2
Reconfigurable intelligent surface (RIS) has emerged as a cost-effective and promising solution to extend the wireless signal coverage and improve the performance via passive signa…
NEAT-MUSIC: Auto-calibration of DOA Estimation for Terahertz-Band Massive MIMO Systems
Ahmet M. Elbir, Abdulkadir Celik, Ahmed M. Eltawil
Terahertz (THz) band is envisioned for the future sixth generation wireless systems thanks to its abundant bandwidth and very narrow beamwidth. These features are one of the key en…
Spherical Wavefront Near-Field DoA Estimation in THz Automotive Radar
Ahmet M. Elbir, Kumar Vijay Mishra, Symeon Chatzinotas
Automotive radar at terahertz (THz) band has the potential to provide compact design. The availability of wide bandwidth at THz-band leads to high range resolution. Further, very n…
Near-field Hybrid Beamforming for Terahertz-band Integrated Sensing and Communications
Ahmet M. Elbir, Abdulkadir Celik, Ahmed M. Eltawil
Terahertz (THz) band communications and integrated sensing and communications (ISAC) are two main facets of the sixth generation wireless networks. In order to compensate the sever…
Terahertz-Band Direction Finding With Beam-Split and Mutual Coupling Calibration
Ahmet M. Elbir, Kumar Vijay Mishra, Symeon Chatzinotas
Terahertz (THz) band is currently envisioned as the key building block to achieving the future sixth generation (6G) wireless systems. The ultra-wide bandwidth and very narrow beam…
Sparse Array Design for Direction Finding using Deep Learning
Kumar Vijay Mishra, Ahmet M. Elbir, Koichi Ichige
In the past few years, deep learning (DL) techniques have been introduced for designing sparse arrays. These methods offer the advantages of feature engineering and low prediction-…
Antenna Selection With Beam Squint Compensation for Integrated Sensing and Communications
Ahmet M. Elbir, Asmaa Abdallah, Abdulkadir Celik +1
Next-generation wireless networks strive for higher communication rates, ultra-low latency, seamless connectivity, and high-resolution sensing capabilities. To meet these demands,…
Spatial Path Index Modulation in mmWave/THz-Band Integrated Sensing and Communications
Ahmet M. Elbir, Kumar Vijay Mishra, Asmaa Abdallah +2
As the demand for wireless connectivity continues to soar, the fifth generation and beyond wireless networks are exploring new ways to efficiently utilize the wireless spectrum and…
NBA-OMP: Near-field Beam-Split-Aware Orthogonal Matching Pursuit for Wideband THz Channel Estimation
Ahmet M. Elbir, Kumar Vijay Mishra, Symeon Chatzinotas
The sixth-generation networks envision the terahertz (THz) band as one of the key enabling technologies because of its ultrawide bandwidth. To combat the severe attenuation, the TH…
Near-Field Terahertz Communications: Model-Based and Model-Free Channel Estimation
Ahmet M. Elbir, Wei Shi, Anastasios K. Papazafeiropoulos +2
Terahertz (THz) band is expected to be one of the key enabling technologies of the sixth generation (6G) wireless networks because of its abundant available bandwidth and very narr…
BSA-OMP: Beam-Split-Aware Orthogonal Matching Pursuit for THz Channel Estimation
Ahmet M. Elbir, Symeon Chatzinotas
Terahertz (THz)-band has been envisioned for the sixth generation wireless networks thanks to its ultra-wide bandwidth and very narrow beamwidth. Nevertheless, THz-band transmissio…
Machine Learning for Metasurfaces Design and Their Applications
Kumar Vijay Mishra, Ahmet M. Elbir, Amir I. Zaghloul
Metasurfaces (MTSs) are increasingly emerging as enabling technologies to meet the demands for multi-functional, small form-factor, efficient, reconfigurable, tunable, and low-cost…
Millimeter-Wave Radar Beamforming with Spatial Path Index Modulation Communications
Ahmet M. Elbir, Kumar Vijay Mishra, Abdulkadir Çelik +1
To efficiently utilize the wireless spectrum and save hardware costs, the fifth generation and beyond (B5G) wireless networks envisage integrated sensing and communications (ISAC)…
Twenty-Five Years of Advances in Beamforming: From Convex and Nonconvex Optimization to Learning Techniques
Ahmet M. Elbir, Kumar Vijay Mishra, Sergiy A. Vorobyov +1
Beamforming is a signal processing technique to steer, shape, and focus an electromagnetic wave using an array of sensors toward a desired direction. It has been used in several en…
A Unified Approach for Beam-Split Mitigation in Terahertz Wideband Hybrid Beamforming
Ahmet M. Elbir
The sixth generation networks envision the deployment of terahertz (THz) band as one of the key enabling property thanks to its abundant bandwidth. However, the ultra-wide bandwidt…
Terahertz-Band Channel and Beam Split Estimation via Array Perturbation Model
Ahmet M. Elbir, Wei Shi, Anastasios K. Papazafeiropoulos +2
For the demonstration of ultra-wideband bandwidth and pencil-beamforming, the terahertz (THz)-band has been envisioned as one of the key enabling technologies for the sixth generat…
Terahertz-Band Integrated Sensing and Communications: Challenges and Opportunities
Ahmet M. Elbir, Kumar Vijay Mishra, Symeon Chatzinotas +1
The sixth generation (6G) wireless networks aim to achieve ultra-high data transmission rates, very low latency and enhanced energy-efficiency. To this end, terahertz (THz) band is…