In cognitive radio (CR), the spectrum sensing of the primary user (PU) may consume some electrical power from the battery capacity of the secondary user (SU), resulting in a decrease in the transmission power of the SU. In this paper, a multislot simultaneous spectrum sensing and energy harvesting model is proposed, which uses the harvested radio frequency (RF) energy of the PU signal to supply...

1389-1286/$ see front matter 2009 Elsevier B.V doi:10.1016/j.comnet.2009.02.009 * Corresponding author. Tel.:+34 93 4017197; fax E-mail addresses: [email protected] ieee.org (X. Gelabert), [email protected] (I.F. A upc.edu (O. Sallent), [email protected] (R. Agustí) 1 This work was conducted during his stay at BWN This paper addresses the problem of opportunistic access of secondary u...

In today’s scenario the introduction of new wireless applications and services and its increasing demand is creating issues in the allocation of the available radio spectrum which is limited and precious resource. As spectrum utilization depends strongly on time and place, a fixed spectrum assignment leads to under utilization of spectrum. Cognitive radio is a new technology which provides a dy...

Spectrum sensing is an essential phase in cognitive radio networks (CRNs). It enables secondary users (SUs) to access licensed spectrum, which is temporarily not occupied by the primary users (PUs). The widely used scheme of spectrum sensing is cooperative sensing, in which an SU shares its sensing results with other SUs to improve the overall sensing performance, while maximizing its throughpu...

Spectrum sensing is an essential phase in cognitive radio networks (CRNs). It enables secondary users (SUs) to access licensed spectrum, which is temporarily not occupied by the primary users (PUs). The widely used scheme of spectrum sensing is cooperative sensing, in which an SU shares its sensing results with other SUs to improve the overall sensing performance, while maximizing its throughpu...

Cognitive radio has attracted considerable attention as an enabling technology for addressing the problem of radio frequency shortages. In cognitive radio networks (CRNs), secondary users (SUs) are allowed to opportunistically utilize the licensed spectrum bands of primary users (PUs) when these bands are temporarily unused. Thus, SUs should monitor the licensed spectrum bands to detect any PU ...

introduction: photonics refers to the technology of generating and harnessing light and other forms of radiant energy whose quantum unit is the photon. photonic technology in the meridian and acupoints research has shown the unique advantages, by which the microcosmic material basis and macroscopic phenomena research can be integrated to interpret the occurrence of propagated sensation along me...

This paper describes a multichannel super-heterodyne signal analyzer, called the Spectrum Analysis Solution (SAS), which performs multi-purpose spectrum sensing to support spectrally adaptive and cognitive radar applications. The SAS operates from ultrahigh frequency (UHF) to the S-band and features a wideband channel with eight narrowband channels. The wideband channel acts as a monitoring cha...

Cognitive Radio (CR) is a novel technology that can improve the utilization efficiency of the radio spectrum and also address the spectrum scarcity problem by opportunistically using the unused channels (spectrum holes / white spaces) in the Licensed Spectrum of Primary Users. Spectrum sensing is the primary function of CR which determines the spectrum holes for opportunistic usage by Secondary...

The idea of software defined radio was proposed by J. Mittola. It was a radio designed on programmable chips. The idea of SDR was further enhanced in the form of Cognitive radios. It was proposed by the J.Mittola for the solution of the Spectrum Scarcity problem. Cognitive Radio based networks have the two types of users. One type of the users is known as primary users and the other are known a...