The coexistence of heterogeneous networks within the same spectrum for enhancing the spectrum efficiency has attracted large interest lately in the research community. Furthermore, the research interest towards the deployment of small cells and multibeam satellites is increasing due to high capacity, easier deployment and higher energy efficiency. However, due to the scarcity of available spect...

With today’s increase in the usage of wireless devices and the consequent spectrum allocation, radio spectrum is becoming scarce. However studies have shown that most of the allotted spectrum is not used for large periods of time. Cognitive radio has been proposed to exploit the presence of these spectrum holes. Spectrum sensing which is one of the most important operations of cognitive radio, ...

Recent studies show that the fixed spectrum assignment policy enforced today results in poor spectrum utilization. To address this problem, the concept of cognitive radio is proposed to address the issue of spectrum efficiency and has been receiving an increasing attention in recent years, since it equips wireless users the capability to optimally adapt their operating parameters according to t...

This paper investigates resource allocation for network-coded primary-secondary cooperation in orthogonal frequency division multiplexing (OFDM)-based cognitive multicast networks, in which cognitive radio (CR), network coding (NC), multicast, and OFDM are effectively combined toward the spectrum efficient fifth generation (5G) wireless communication systems. Different from the conventional one...

Cognitive radio (CR) offer solution by utilizing the spectrum holes in space without introducing an unacceptable fear of harmful interference for the primary user. And also solve the spectrum inefficiency and spectrum scarcity problem. That are represented the potential opportunities for non-interfering use of spectrum which requires three main tasks Spectrum Sensing, Spectrum Analysis and Spec...

Cognitive radio (CR) can significantly improve spectrum efficiency by allowing the secondary users to temporarily access the primary user’s under-utilized licensed spectrum. Spectrum mobility issues arise when the primary user appears at the channels being occupied by the secondary users. The secondary users to return the occupied channel because the primary users have the preemptive priority t...

We consider a cognitive radio network in which a multiple-access secondary system coexists with an automatic repeat request (ARQ)-based primary system under heavy primary traffic. To achieve spectrum sharing without degrading the performance of the primary system, the secondary transmitters alternate between cooperation and access modes based on a credit system. In the cooperation mode, the sec...

Address for Correspondence Head of the Department, PG Student, Kamaraj College of Engineering and Technology, Virudhunagar, Tamilnadu India. ABSTRACT In this paper to propose an approach for detecting the presence of malicious attack which is commonly known as primary user emulation attack (PUEA), this type of attack act as the primary signal and delude the secondary user and occupy the whole f...

Secondary spectrum access emerges as a means to increase spectrum utilization significantly in a near future. However, the technical availability and the economic value of the secondary access have not been fully investigated. Particularly, the impact of the secondary access on the real-life primary systems remains mostly unaddressed. Among the primary systems of interest are aeronautical commu...

Recent studies show that the fixed spectrum assignment policy enforced today results in poor spectrum utilization. To address this problem, the concept of cognitive radio is proposed to address the issue of spectrum efficiency and has been receiving an increasing attention in recent years, since it equips wireless users the capability to optimally adapt their operating parameters according to t...