The most important components of the cognitive radio concept is its ability to measure, sense and learn. One also should be aware of the parameters related to the radio channel characteristics and the availability of spectrum and power. In cognitive radio technology, primary users can be defined as the users who have the highest priority on the usage of a specific part of the spectrum. Secondar...

Spectrum inefficient utilization and growing in demand of wireless services is one of the challenges facing the wireless communication systems as the spectrum is a finite resource. There is a need of better and smarter exploitation of the limited spectrum which will enables the usage and to allowing sharing of temporally unused spectrum allocated to the television broadcast service in non inter...

The efficient utilization of underutilized spectrum is the main theme of current research. The cognitive radio with the help of Q-learning algorithm is used to detect the presence of primary signals and utilize the spectrum in the absence of primary signals. The proposed Q-learning algorithm model identifies previously known signals and learns to detect the signals which otherwise could not be ...

dynamic spectrum access (DSA) that promises to alleviate the spectrum shortage problem in wireless networks. By employing spectrum sensing techniques or referring to the geolocation databases, a CR (or a CR-enabled secondary user) is able to intelligently decide which licensed spectrum band is free for use without causing harmful interference to licensed (or primary) users. Besides, the spectru...

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. More...

Sharing of spectrum has been identified as a key requirement in cognitive radio networks(CRNs). We address the problem of spectrum sharing with spectrum pricing where the primary user wants to sell the spectrum to the secondary users. By equilibrium pricing scheme, each of the players in the spectrum sharing game aims to take the strategy which maximize its own profit under sojourn-time constra...

Due to introduction of smart phones with data intensive multimedia and interactive applications and exponential growth of wireless devices, there is a shortage for useful radio spectrum. Even though the spectrum has become crowded, many spectrum occupancy measurements indicate that most of the allocated spectrum is underutilised. Hence radically new approaches in terms of allocation of wireless...

Cognitive radio is a new concept of reusing licensed spectrum in an unlicensed manner. The motivation for cognitive radio is various measurements of spectrum utilization, that generally show unused resources in frequency, time and space. These ”spectrum holes” could be exploited by cognitive radios. Some studies suggest that the spectrum is extremely underutilized, and that these spectrum holes...

Cognitive radio networks provide the capability to share the wireless channel with licensed (primary) users in an opportunistic manner. Primary users have a license to operate in a certain spectrum band; their access can only be controlled by the Primary Operator and is not affected by any other unlicensed (secondary) user. On the other hand, secondary users (SUs) have no spectrum license, and ...