The growing demand of wireless applications has put a lot of constraints on the usage of available radio spectrum which is limited and precious resource. However, a fixed spectrum assignment has lead to under utilisation of spectrum as a great portion of licensed spectrum is not effectively utilised. Cognitive radio is a promising technology which provides a novel way to improve utilisation eff...

Abstract—Cooperative spectrum sensing is a crucial challenge in cognitive radio networks. Cooperative sensing can increase the reliability of spectrum hole detection, optimize sensing time and reduce delay in cooperative networks. In this paper, an efficient central capacity optimization algorithm is proposed to minimize cooperative sensing time in a homogenous sensor network using OR decision ...

Soil salinity phenomena are one of the main problems of arid and semi-arid lands. Saline soils constitute a huge part of Iran, and also threaten its neighboring lands. Therefore, in order to optimum exploitation of such soils, qualitative monitoring is necessary. Recently, remote sensing techniques have been increasingly applied in monitoring soil characteristics. The present study was carried ...

Nowadays the demand of the wireless application has grown from day to day life. The Demand of wireless applications has put a many of constraints on the use of available radio spectrum which is a limited and precious resource. The static spectrum assignment leads to underutilization of the spectrum as a great portion of the licensed spectrum is not efficiently utilized. Cognitive radio (CR) is ...

Enabling cognitive radio (CR) requires revisiting the traditional task of spectrum sensing with specific and demanding requirements in terms of detection performance, real-time processing, and robustness to noise. Unfortunately, conventional spectrum sensing methods do not satisfy these demands. In particular, the Nyquist rate of signals typically sensed by a CR is prohibitively high so that sa...

An explosive growth in vehicular wireless applications gives rise to spectrum resource starvation. Cognitive radio has been used in vehicular networks to mitigate the impending spectrum starvation problem by allowing vehicles to fully exploit spectrum opportunities unoccupied by licensed users. Efficient and effective detection of licensed user is a critical issue to realize cognitive radio app...

Cognitive radio (CR) is a promising technology which avoids congestion in wireless communication by exploiting unused radio spectrum. The Spectrum sensing (SS) plays a fundamental requirement of CR which finds an unused free spectrum and detects the licensed user transmissions. This paper constitutes the study about the classification of spectrum sensing in energy detection, cyclostationary, ma...

Radio spectrum has turned into a precious natural resource from free goods due to the rapid development of wireless communication technology. In order to efficiently utilize radio spectrum, a spectrum policy should be enough appropriate to create new industries and new technologies. From this point of view, we have developed a distributed spectrum sensing system which collects dense information...

Cognitive radio (CR) has recently been identified as a promising technology to solve the spectrum inefficiency problem. CR users or secondary users (SUs) need to sense the presence of primary users (PUs) constantly and rapidly to utilize their unused spectrum. However, detection is compromised when a user experiences shadowing or fading effects. In such cases, the user cannot distinguish betwee...

Compressive sampling (CS), or compressive sensing, has the ability for reconstructing a sparse signal with small number of measurements. There are some applications like spectrum sensing in cognitive radio which not necessarily need a perfect reconstruction. Consequently in this application, toward the decrement of high signal acquisition costs in wideband system, CS methods have been used for ...