Results 51 to 60 of about 3,285 (273)
Cyclostationary Feature Detection Based on Compressed Sensing and Wavelet De-Noising
Dianxin kexue, 2015 To improve the vacant spectrum utilization，ultra-wideband spectrum sensing is critical for cognitive radio （CR）as it enables secondary users to dynamically access the unoccupied spectrum bands.However，the fast and accurate spectrum sensing is still a ...
Haifeng Tan +3 more
doaj +2 more sources
Cooperative Spectrum Sensing Algorithm Based on CS-SLIM Iterative Minimization Sparse Learning
International Journal of Distributed Sensor Networks, 2013 Dynamic spectrum management is a key technology in cognitive wireless sensor network (C-WSN), in which spectrum sensing plays an important role. In this paper, we propose an improved approach as sparse learning via iterative minimization based on ...
Ning Cao, Xiaowen Hu, Hao Lu, Minghe Mao
doaj +1 more source
Enhanced compressive wideband frequency spectrum sensing for dynamic spectrum access [PDF]
EURASIP Journal on Advances in Signal Processing, 2012 Wideband spectrum sensing detects the unused spectrum holes for dynamic spectrum access (DSA). Too high sampling rate is the main problem. Compressive sensing (CS) can reconstruct sparse signal with much fewer randomized samples than Nyquist sampling with high probability.
Yipeng Liu 0001, Qun Wan
openaire +2 more sources
Orbital Geometry‐Governed Response of Pressure‐Tunable Quantum Defects in hBN
Advanced Functional Materials, EarlyView.Defects in hBN act as ultrasensitive quantum manometers when the energy of the intradefect optical transitions is modified by lattice compression. The orbital geometry of the electron wave functions governs how electron hopping and Coulomb interactions react uniquely to the reduction of the van der Waals gap and in‐plane compression, leading to robust ...
Magdalena Grzeszczyk +6 more
wiley +1 more source
Cognitive MAC protocols for mobile Ad-Hoc networks [PDF]
, 2013 This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The term of Cognitive Radio (CR) used to indicate that spectrum radio could be accessed dynamically and opportunistically by unlicensed users.
Masrub, Abdullah Ashur
core
Large Transverse Thermoelectric Effect in Weyl Semimetal TaIrTe4 Engineered for Photodetection
Advanced Functional Materials, EarlyView.This experimental work shows that the anomalous scanning photocurrent response patterns of the Weyl semimetal TaIrTe4${\rm TaIrTe}_4$ under visible and long‐wave infrared illumination are due to a large transverse thermoelectric response of the material.
Morgan G. Blevins +6 more
wiley +1 more source
Advanced Functional Materials, EarlyView.A quantum dot–tellurium thin‐film photodetector autonomously discriminates visible and infrared wavelengths through polarity‐reversible photoresponses. Engineered carrier separation and gain modulation enable filter‐free multispectral sensing within a single‐device architecture.
Yong Min Lee +7 more
wiley +1 more source
Sub-Nyquist Wideband Spectrum Sensing and Sharing [PDF]
, 2017 PhDThe rising popularity of wireless services resulting in spectrum shortage has motivated dynamic spectrum sharing to facilitate e cient usage of the underutilized spectrum.
Ma, Yuan
core
Wideband and Multiband Temporal Sensing for Opportunistic Spectrum Access
, 2018 Opportunistic spectrum access is a proposed solution to the problem of increasing scarcity of radio resources. In certain bands, spectrum is utilized extremely inefficiently by the licensed, or primary, users.
Bruno, Joseph M
core +1 more source
Chiral Phase Change Nanomaterials
Advanced Functional Materials, EarlyView.This work demonstrates reversible, non‐volatile phase transitions in chiral Ge2${\rm Ge}_2$Sb2${\rm Sb}_2$Te5${\rm Te}_5$ (GST) nanohelices for high‐speed optical modulation of chirality and dynamic control of the state of polarization (SOP). The chiral nanostructures are fabricated using a highly directional, wafer‐scale physical vapor deposition ...
Joshua A. Burrow +11 more
wiley +1 more source