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.
Secondary users (SUs) can flexibly access licensed channels to improve the spectrum utilization in cognitive radio networks (CRNs). In mobile cognitive radio ad hoc networks (MCRAHNs) where nodes can move, SUs are intermittently connected because of node mobility, as well as the uncertain channel availability. Providing multicast services in MCRAHNs is urgently needed with the compelling demand on...
Cooperative spectrum sensing can improve the detection reliability in cognitive radio network. How to report the local sensing results to the fusion center has not aroused much interest. Since OFDM has been widely recognized as a promising candidate for cognitive radio in opportunistic spectrum access scenarios, a OFDMA-based sensing reporting scheme is designed. Correspondingly, several fusion rules...
In the scenario of dynamic spectrum access application for cognitive radio (CR), the spectrum-sidelobe problem of OFDM (orthogonal frequency division multiplexing) must be considered. A precoding ahead of IDFT (inverse discrete Fourier transformation) is presented to suppress the in-band-out-of-subband (IBOSB) radiation. Its design is based on generalized eigenvalue problem. In order to improve its...
OFDM is one of the best physical-layer candidates for cognitive radio (CR) systems, but rectangular pulse shaping gives rise to large spectrum sidelobes and interferes with the licensed user on the adjacent band. In this paper, an approach is derived based on the signal continuity to measure the spectral decay rate of the shaping pulse for OFDM. And a novel family of pulses, the power of sech function,...
Optimal spectrum access is a fundamental issue for efficient wireless communications in multi-channel wireless networking systems. Opportunistic spectrum access, making fully use of channels with high quality, could pave a way for efficient transmission. Unfortunately, in heterogeneous wireless networks, these strategies suffer from the assumption of identical wireless channel quality, and the difficulties...
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.