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 this paper, we investigate an optimization of threshold level with energy detection to improve the spectrum sensing performance. Determining threshold level to minimize spectrum sensing error both reduces collision probability with primary user and enhances usage level of vacant spectrum, resulting in improving total spectrum efficiency. However, when determining threshold level, spectrum se...

Cognitive radio is an emerging technology that aims for efficient spectrum usage. Cognitive radios have been proposed as a solution to the spectrum underutilization problem and have been proven to increase spectrum efficiency . However, in this we are analyzing the performance of the cognitive radio based on cooperative spectrum sharing. Here we propose a twophase spectrum sharing protocol whic...

in this paper we introduce the notion of classical quasi-primary submodules that generalizes the concept of classical primary submodules. then, we investigate decomposition and minimal decomposition into classical quasi-primary submodules. in particular, existence and uniqueness of classical quasi-primary decompositions in finitely generated modules over noetherian rings are proved. moreover, w...

The paper suggests a radio mode identification algorithm for spectrum sensing that utilizes time frequency analysis and digital image processing techniques to identify various transmission parameters of the primary users. Identification of the spectral holes within the frequency band under observation has been of major interest in the research on spectrum sensing techniques; however the propose...

Cross-layer approach in cognitive wireless networks is proposed for efficient use of spectrum by detecting primary signals. The detection may be false detection of primary signal, missed detection of primary signal, or correct detection of primary signal. The quick and correct detection of primary signal will be helpful for utilization of the idle spectrum. In the current research, Su’s algorit...