Results 71 to 80 of about 22,442 (264)

Wideband Spectrum Sensing by Model Order Selection [PDF]

IEEE Transactions on Wireless Communications, 2015
Spectrum sensing is an essential functionality in cognitive radio (CR) systems allowing us to discover spectrum opportunities and enabling primary user (PU) protection. Wideband spectrum sensing (WS) improves the awareness of the surrounding radio environment by jointly monitoring multiple frequency bands.
MARIANI, ANDREA, GIORGETTI, ANDREA, CHIANI, MARCO   +2 more
openaire   +1 more source

Circular‐Polarization‐Sensitive Organic Photodetectors with a Chiral Nanopatterned Electrode Inverse‐Designed by Genetic Algorithm

Advanced Functional Materials, EarlyView.
A chiral photodetector capable of selectively distinguishing left‐ and right‐handed circularly polarized light is experimentally demonstrated. The device, which features a nanopatterned electrode inverse‐designed by a genetic algorithm within a metal–dielectric–metal nanocavity that incorporates a vacuum‐deposited small‐molecule multilayer, exhibits ...
Kyung Ryoul Park, Jewoong Lee, In‐Suk Choi, Changsoon Kim   +3 more
wiley   +1 more source

A Novel Decentralized Scheme for Cooperative Compressed Spectrum Sensing in Distributed Networks

International Journal of Distributed Sensor Networks, 2015
Compressed sensing (CS) recently turns out to be an effective approach to alleviate the sampling bottleneck in wideband spectrum sensing. However, the computation overhead incurred by compressed reconstruction is nontrivial, especially in a power ...
Huang Jijun, Zha Song
doaj   +1 more source

S-transformation based integrated approach for spectrum estimation, storage, and sensing in cognitive radio

Digital Communications and Networks, 2019
Cognitive Radio (CR) uses the principle of dynamic spectrum allocation to improve the utilization of spectrum bands. The estimation of missing data is essential for maintaining an uninterrupted quality of service in the CR.
Pyari Mohan Pradhan, Ganapati Panda
doaj   +1 more source

Wide-band planar inverted-F antenna for cognitive radio [PDF]

, 2009
A wide-band Planar Inverted-F Antenna (PIFA) is presented. The proposed antenna is simply structured consist of main patch supported by shorting wall and shorting pin, fed by 50 ohm microstrip transmission line. The antenna achieves an enhanced impedance
AbuTarboush, HF, Al-Raweshidy, H, Budimir, D, Nilavalan, R   +3 more
core  

Broadband, Flexible, Skin‐Compatible Carbon Dots/Graphene Photodetectors for Wearable Applications

Advanced Functional Materials, EarlyView.
Broadband, flexible photodetectors integrating nitrogen‐rich carbon dots with single‐layer graphene on plastic substrates are demonstrated. A biocompatible chitosan–glycerol electrolyte enables efficient low‐voltage gating and on‐skin operation. The devices exhibit ultraviolet‐to‐near‐infrared response, mechanical robustness under bending, and verified
Nouha Loudhaief, Petr Rozhin, Ilaria Bertuol, Ali Raza, Leonardo Viti, Subhankar Roy, Enrico Cavarzerani, Luca Sbuelz, Matteo Brilli, Andrea Serinolli, Jacopo Nicoletti, Riccardo Piccoli, Sebastián Castilla, Simone Dal Zilio, Enrique Rodríguez‐Castellón, Miriam Serena Vitiello, Maurizio Selva, Flavio Rizzolio, Alvise Perosa, Giovanni Antonio Salvatore, Domenico De Fazio   +20 more
wiley   +1 more source

An adaptive approach for integrating primary user behavior in compressive spectrum sensing

EURASIP Journal on Wireless Communications and Networking
Compressive sensing (CS) has been widely used to sense the wideband spectrum with fewer measurements by taking advantage of radio spectrum underutilization.
Ahmed A. Tawfik, Sherif M. Abuelenin, Mohamed F. Abdelkader   +2 more
doaj   +1 more source

Distributed Compressed Spectrum Sensing via Cooperative Support Fusion

International Journal of Distributed Sensor Networks, 2013
Spectrum sensing in wideband cognitive radio (CR) networks faces several significant practical challenges, such as extremely high sampling rates required for wideband processing, impact of frequency-selective wireless fading and shadowing, and limitation
Zha Song, Huang Jijun, Liu Peiguo, He Jianguo   +3 more
doaj   +1 more source

Three‐Dimensional Hierarchical Nanowire‐Networks with Deep‐Focus Tolerance and Adhesion Robustness for Harsh‐Environment SERS Sensing

Advanced Functional Materials, EarlyView.
A 3D nanowire‐network SERS substrate with robust adhesion is developed, featuring pronounced z‐direction optical activity, ultralow detection limit (1.5 × 10−13 M), and excellent signal uniformity (RSD < 10%). Enabled by enhanced light scattering, increased optical density of states, and structural reinforcement, the substrate demonstrates stable, high‐
Jinglai Duan, Wentao Wang, Xiu Liang, Yongliang Zhang, Jie Liu, Yu Bai, Dangyuan Lei   +6 more
wiley   +1 more source

High Entropy Wide‐Bandgap Borates with Broadband Luminescence and Large Nonlinear Optical properties

Advanced Functional Materials, EarlyView.
High‐entropy rare‐earth borates exhibit excellent nonlinear optical and broadband luminescence properties arising from multi‐component doping, chemical disorder, increased configurational entropy, and increased lattice and electronic anharmonicity. This formulation enabled us to obtain a large, environmentally stable single crystal with 3X higher laser‐
Saugata Sarker, Yu Wang, Yongwen Sun, Caeli Benyacko, Saeed S.I. Almishal, Tao Zhou, Zhiyu Zhang, Jadupati Nag, Himirkanti Sarkar, Jeffrey Shallenberger, Hemant Yennawar, Yang Yang, Jon‐Paul Maria, Zhiqiang Mao, Venkatraman Gopalan   +14 more
wiley   +1 more source