Results 221 to 230 of about 108,306 (265)

Effective schemes for OFDM sidelobe control in fragmented spectrum use

2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), 2013
OFDM as multicarrier scheme provides adaptive functionality that is required to implement waveform processing for cognitive radio, dynamic spectrum use and fragmented coexistence scenarios. However, OFDM faces some difficulties due to the relatively strong sidelobes around the active subcarriers, which introduces interference effects between adjacent ...
Loulou Alaa Eddin, Renfors Markku
openaire   +1 more source

How Problematic is Spectrum Fragmentation in Operator’s Gridless Network?

2014
Spectrum Fragmentation (SF) is considered as a drawback of Gridless Technology (GT). In this paper, we study the impact of SF in a specific incremental traffic scenario and show to what extent anticipating traffic growth can reduce this impact and improves the spectrum usage for next generation of transponders.
Amar, D., Le Rouzic, Esther, Brochier, Nicolas, Jean-Luc, Auge, Lepers, Catherine, Perrot, Nancy, Fazel, Sina   +6 more
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Infrared spectrum of NH4+(H2O): Evidence for mode specific fragmentation

The Journal of Chemical Physics, 2007
The gas phase infrared spectrum (3250–3810cm−1) of the singly hydrated ammonium ion, NH4+(H2O), has been recorded by action spectroscopy of mass selected and isolated ions. The four bands obtained are assigned to N–H stretching modes and to O–H stretching modes.
Tobias, Pankewitz, Anita, Lagutschenkov, Gereon, Niedner-Schatteburg, Sotiris S, Xantheas, Yuan-Tseh, Lee   +4 more
openaire   +2 more sources

Infrared Spectrum of an Anticodon Fragment of a Transfer RNA

Nature, 1969
WE have observed the infrared spectrum of a fragment of a transfer RNA (tRNA) in aqueous solution and obtained evidence for the existence of the hydrogen-bonded base pairs.
K, Morikawa, M, Tsuboi, Y, Kyogoku, T, Seno, S, Nishimura   +4 more
openaire   +2 more sources

Routing and Spectrum Assignment Algorithm based on Spectrum Fragment Assessment of Arriving Services

2019 28th Wireless and Optical Communications Conference (WOCC), 2019
Elastic Optical Network (EON) is the promising solution for future optical networks. Spectrum fragments is one of the key issues in EON which will affect the allocation of subsequent services and the utilization of spectrum resource. This paper proposes an improved RSA algorithm for elastic optical network based on spectrum fragment assessment of ...
Bokai Cheng, Cheng Hang, Yunfei Hu, Shixin Liu, Jiaoliang Yu, Yutong Wang, Jianhua Shen   +6 more
openaire   +1 more source

Efficient Hybrid Grouping Spectrum Assignment to Suppress Spectrum Fragments in Flexible Grid Optical Networks

Journal of Lightwave Technology, 2017
Flexible grid optical networks (FONs) can accommodate diverse kinds of service connections with higher networking flexibility and spectrum-utilization efficiency by employing a finer resource allocation granularity (known as frequency slot) and a more sophisticated path-routing and resource-allocation algorithm (known as routing and spectrum assignment
Yang Qiu, Jing Xu
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Fragmentation-avoiding spectrum assignment algorithm based on time-spectrum partition for elastic optical networks

Optical Fiber Technology, 2019
Abstract In order to address the fragmentation problem in the time domain and the spectrum domain in elastic optical networks, a fragmentation-avoiding spectrum assignment algorithm based on time-spectrum partition (FASA-TSP) is proposed. Firstly, a time-spectrum partition method, splitting whole optical spectrum into several spectrum partitions and ...
Huanlin Liu, Hao Hu, Yong Chen, Lixiang Du   +3 more
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Adaptive spectrum access strategies in the context of spectrum fragmentation in cognitive radio networks

Concurrency and Computation: Practice and Experience, 2012
SUMMARYBecause of the presence of incumbents in cognitive radio networks, the unused spectrum in the TV bands, popularly referred to as ‘white spaces’, are fragmented with the size of each fragment varying from one TV channel to several TV channels. What is more, because the secondary transmissions adjust their spectrum usage over time, white spaces ...
Yanhui Lu, Huijin Cao, Xiaomin Mu, Shouyi Yang   +3 more
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Efficient broadcast on fragmented spectrum in cognitive radio networks

2015 IEEE Conference on Computer Communications (INFOCOM), 2015
To improve spectrum utilization, cognitive radio (CR) is introduced to detect and exploit available spectrum resources autonomously. The flexible spectrum use imposes special challenges on broadcast because different CR devices may detect different available spectrum fragments at different locations.
Pei Huang, Chin-Jung Liu, Xi Yang, Li Xiao   +3 more
openaire   +1 more source

Fragment methods for IR spectrum calculations of organophosphorus compounds

Journal of Structural Chemistry, 2006
For highly toxic organophosphorus compounds on the limiting lists of the International Chemical Weapons Ban Treaty, fragment methods may be used for calculating their IR vibrational spectra; this is shown for O-alkyl alkylfluorophosphonates used as examples.
B. F. Myasoedov, L. A. Gribov, A. I. Pavlyuchko, I. V. Rybalchenko, G. I. Sigeikin, A. F. Kireev, V. N. Suvorkin   +6 more
openaire   +1 more source