Results 61 to 70 of about 27,142 (205)

Review of millimeter‐wave and terahertz near‐field synthetic aperture radar imaging technology

InfoScience, EarlyView.
Abstract This paper comprehensively reviews the development of millimeter‐wave (MMW) and terahertz (THz) near‐field imaging technologies, with an emphasis on the state of synthetic aperture radar (SAR)‐based imaging technologies. Near‐field imaging technologies are categorized into passive and active imaging modes, among which active imaging is favored
Qi Yang, Hongqiang Wang, Xu Chen, Xin Peng   +3 more
wiley   +1 more source

Multi-Beam Radar Communication Integrated System Design

Information, 2023
In this paper, we propose a multi-beam integrated radar and communication scheme using phased-array antenna, in which the same LFM-BPSK integrated waveform is used for both the radar and the communication beams.
Hao Ma, Jun Wang, Xin Sun, Wenxin Jin
doaj   +1 more source

Non‐Uniform Programmable Photonic Waveguide Meshes

Laser &Photonics Reviews, EarlyView.
Integrating defect cells into uniform hexagonal waveguide meshes overcomes the fundamental spectral and temporal limitations of programmable photonics. By leveraging the Vernier effect through non‐uniform coupled cavities, this architecture achieves a tenfold increase in free spectral range and ultra‐fast sampling times, paving the way for next ...
Cristina Catalá‐Lahoz, José Capmany
wiley   +1 more source

Application of Beamforming Technology in Ionospheric Oblique Backscatter Sounding with a Miniaturized L-Array

Remote Sensing, 2020
In this paper, a new dedicated multi-channel ionospheric oblique backscatter sounder is described. A miniaturized L-shaped antenna array was employed for the receiving of the oblique backscatter echoes in the present system. Firstly, two typical adaptive
Tongxin Liu, Guobin Yang, Zhengyu Zhao, Chunhua Jiang, Yaogai Hu   +4 more
doaj   +1 more source

Adaptive Beamforming and Adaptive Modulation-Assisted Network Performance of Multiuser Detection-Aided FDD and TDD CDMA Systems

, 2007
The network performance of a frequency division duplex and time division duplex (TDD) code division multiple access (CDMA)-based system is investigated using system parameters similar to those of the Universal Mobile Telecommunication System.
Blogh, J.S., Hanzo, L., Ni, S.
core   +1 more source

Nearfield broadband adaptive beamforming [PDF]

ISSPA '99. Proceedings of the Fifth International Symposium on Signal Processing and its Applications (IEEE Cat. No.99EX359), 2003
A nearfield broadband adaptive beamforming approach based on the modal expansion of the solution to the spherical wave equation is formulated. It provides an efficient parameterization for the nearfield beamforming problem with a single parameter to focus the beamformer to a desired operating radius and a set of modal coefficients to control the ...
T.D. Abhayapala, R.A. Kennedy, R.C. Williamson, D.B. Ward   +3 more
openaire   +1 more source

Preprocessing Procedure for Propagation Measurements on MEO Satellite Links

International Journal of Satellite Communications and Networking, EarlyView.
ABSTRACT This paper presents a software tool designed for preprocessing data from an experimental campaign aimed at characterizing the tropospheric propagation channel using Medium Earth Orbit (MEO) satellites. The collected data provide critical insights into the channel in scenarios involving continuous variations in azimuth and elevation, along with
Marlene Brás, Susana Mota, Armando Rocha   +2 more
wiley   +1 more source

A Robust Capon Beamforming Approach for Sparse Array Based on Importance Resampling Compressive Covariance Sensing

IEEE Access, 2019
Reconstructing the interference-plus-noise covariance matrix instead of searching for the optimal diagonal loading factor for the sample covariance matrix is a good method for calculating the adaptive beamforming coefficients.
Yuguan Hou, Hefu Gao, Qinghong Huang, Jinzi Qi, Xingpeng Mao, Cunfeng Gu   +5 more
doaj   +1 more source

Adaptive Multicell 3D Beamforming in Multi-Antenna Cellular Networks

, 2015
We consider a cellular network with multi-antenna base stations (BSs) and single-antenna users, multicell cooperation, imperfect channel state information, and directional antennas each with a vertically adjustable beam.
Coldrey, Mikael, Heath Jr., Robert W., Seifi, Nima, Svensson, Tommy   +3 more
core   +1 more source

Tracing Three Decades of Low Earth Orbit Satellite Communication Development: A Bibliometric and Main Path Analysis of Network Architectures, Protocol Evolution, and Emerging Intelligent Services

International Journal of Satellite Communications and Networking, EarlyView.
ABSTRACT Low Earth Orbit (LEO) satellite communication systems have evolved into a critical component of global broadband networks, enabling wide‐area connectivity, IoT services, and intelligent multilayer satellite–terrestrial integration. Despite rapid advancements in constellation deployment, routing mechanisms, resource management, and LEO–5G/6G ...
Wei‐Hao Su, Ya‐Chen Chuang, Long‐Sheng Chen   +2 more
wiley   +1 more source