The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Filter bank multicarrier with offset quadrature amplitude modulation (FBMC-OQAM) signaling offers almost the full spectral efficiency (one complex symbol per unit area in the time-frequency plane) for long data packets. However, because of the ramp-up and ramp-down of the waveform at the beginning and the end of each packet, its spectral efficiency can drop significantly in short packets/data bursts...
In this paper, a low overhead preamble structure is proposed for the interference approximation method — complex (IAM-C) method in offset quadrature amplitude modulation based orthogonal frequency division multiplexing (OQAM-OFDM) systems. Compared with the conventional preamble structure with three columns of symbols, the proposed preamble structure only requires two columns of symbols as the preamble...
The Duffing-Van der Pol equation with fifth nonlinear-restoring force and one external forcing term is investigated. The existence and bifurcations of harmonic and second-order sub harmonic, and third-order sub harmonic, third-order super harmonic under small perturbations are obtained by using second-order averaging method.
In this paper we present analytical and numerical results concerning the inhibition of chaos in DufŒng-van der Pol system with Œth nonlinear-restoring force and two external forcing terms. We theoretically give parameter-space regions interval of initial phase difference on the basis of Melnikov methods proposed in, where homoclinic chaos can be suppressed. Numerical simulation results show the consistence...
In this paper, we propose a novel spectrum sensing technique, called as multi-slot spectrum sensing, to detect spectral holes and to opportunistically use under-utilized frequency bands without causing harmful interference to legacy (primary) networks. The key idea of the proposed sensing scheme is to combine the observations from the past N (N ?? 2) sensing blocks including the latest one. Specifically,...
To improve the spectrum utilization, more and more attention was paid to OFDM based opportunistic spectrum access (OSA) systems in recent years. In this paper, to enable coexistence between a secondary user and a primary user, a novel method called EAIC was proposed for spectral sculpting of OFDM signal effectively. In EAIC, however, the cancellation signals cause self-interferences to OFDM data tones...
Autonomic networks are networks that are self- organized with decentralized control and management. Accurate trust establishment and maintenance is essential for secure and reliable message transmissions in autonomic networks. Because of the mobility and dynamics, trust management in autonomic networks is a much more dynamic problem than in traditional server-based networks. In traditional networks,...
Knowledge delivery based on business process context can provide users the knowledge related to tasks in the business process. However, the providing knowledge tends to overload and disorient users due to excessive knowledge and unlimited knowledge links. To solve these problems, the extended user model, the levels of knowledge item, and the directed link vector are introduced to optimize the knowledge...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.