The key challenge of spectrum sensing is the Detection of weak signals or primary user in noise with a very small probability of miss detection, which requires better understanding of very low SNR regimes. Cognitive radio allows unlicensed users to access licensed frequency bands through dynamic spectrum access so as to reduce spectrum scarcity. The spectrum sensing problem has gained new aspec...

Cognitive radio (CR) has been an active research topic in wireless communications. In this dissertation, radio behavior and potential security threats in cognitive radio networks are investigated in order to successfully deploy CR networks and realize its benefits. We study complex CR misuse issues during its secondary access processes, including misbehavior, cheating, and attack. Different cou...

Networking cognitive radios and nodes from primary system (PS) results in a heterogeneous coexisting multiradio wireless network, so that significant network throughput gain can be achieved. However, by investigating cognitive radio network (CRN) architecture, the links in CRNs are unlikely to support complete security check due to link dynamics, opportunistic availability, and uni-directional ...

Beyond 3G (B3G) wireless connectivity can efficiently be realized by exploiting cognitive networking concepts. Cognitive systems dynamically reconfigure the Radio Access Technologies (RATs) and the spectrum they use, based on experience, in order to adapt to the changing environment conditions. However, dynamic reconfiguration decisions call for robust discovery, i.e. radio-scene analysis and c...

Control Channel Dilemma (CCD) is still an open problem for Cognitive Radio Network (CRN). In this article, we investigate and present a novel solution of Distributed Coordination in CRN to mitigate the necessity for a common control channel. This scheme is based on the fact that a group of nearby nodes almost detects the same frequency spectrum. That will allow every group of close nodes to cho...

A cognitive radio (CR) is a transceiver that is aware, adaptive, and capable of learning. It may be visualized and realized as an intelligent software package (cognitive engine) controlling a software defined radio platform. The cognitive engine executes a set of nested loops constituting a cognition cycle, drawing on experience and stored knowledge to optimize a set of user-chosen quality of s...

In modern societies, spectrum bands become very expensive and highly requested resources. Many applications based on wireless communications require smart collaboration and wise sharing of available resources. To achieve this goal, concepts of cognitive radio have been recently formulated. Even though, these systems are newly proposed, many researchers are becoming enthusiastically involved in ...

This paper presents a spatially distributed and dynamic billing, pricing and allocation mechanism for which a user terminal requires Cognitive Radio abilities. That is, the Cognitive Radio abilities will be applied to the economical environment. The radio resource goods are allocated to the users by a multi-unit sealed-bid auction. Intelligent entities like the bidding strategy have to represen...

This paper introduce the concept of cognitive UWB radio, a wireless system based on UWB transmission able to self adapt to the characteristics of the surrounding environment. UWB is an promising underlying method for coexistence among different systems. However, the performance may not be as good as expected due to the changing spectrum environment. Thus, cognitive UWB radio is proposed by taki...

In this paper, resource allocation models for cognitive radio networks (CRN) using game theory are presented. The study includes the concept of cognitive radio (CR) networks, cooperative and non-cooperative game theory, and modeling of strategic interaction process for CR enabled secondary users. The prime objective of the present study is to compare existing game models for CR networks in term...