This paper presents a sophisticated radio spectrum measurement platform specifically envisaged and designed for spectrum occupancy surveys in the context of Dynamic Spectrum Access/Cognitive Radio (DSA/CR). The presented tool is a very flexible computercontrolled radio measurement system, which has successfully been used in extensive spectrum measurement campaigns and empirical studies in the c...

Cognitive Radio (CR) has risen as a tempting solution to the problem of spectral inefficiency as it performs sensing of the radio environment, sharing it without harmful interference to Primary Users (PU) and quickly quitting the frequency band if the corresponding licensed user emerges. Spectrum Sensing is the most crucial task for the establishment of cognitive radio based communication mecha...

Cognitive radio (CR) has been seen as a promising technology to make radio spectrum usage more effective by providing an opportunistic access for secondary users to the licensed spectrum areas. CR systems need to detect the presence of a primary user (PU) signal by continuously sensing the spectrum area of interest. Radiowave propagation effects like fading and shadowing often complicate the de...

Radio spectrum is a very scarce and important resource for wireless communication systems. However, a recent study conducted by Federal Communications Commission (FCC) found that most of the currently allocated radio spectrum is not efficiently utilized by the licensed primary users. Granting opportunistic access of the spectrum to unlicensed secondary users has been suggested as a possible way...

The cognitive radio (CR) is evolved as the potential technology to solve the problem of spectrum scarcity and to meet the stringent requirements of upcoming wireless services. CR has two distinct features, the spectrum sensing and the parameter adaptation. The former feature helps the CR to find the vacant spectrum slots/channels in the radio band while the latter mechanism allows it to adjust ...

Although wireless mesh networks (WMNs) have quickly been successfully deployed, the dual usage of wireless communication makes them very resource dependent. Proposed cognitive radio (CR) concepts appear to be a good solution to provide WMNs with additional bandwidth and improved efficiency. In addition, we believe that applying CR to WMN can be very beneficial to CR, speeding the development an...

In the last years, an increasing attention of the communications researchers has been focused on the Cognitive Radio (CR) concept and on its possible supporting technologies and applications. The proposed approach deals the problem of information acquisition and handling for cooperative Cognitive Radio Terminals, in order to perform Spectrum Sensing tasks in a distributed way. The proposed solu...

Cognitive Radio (CR) is a technology that promises to solve the spectrum shortage problem by allowing secondary users to coexist with primary user without causing any interference to the communication. It aims to improve the utilization of the radio spectrum. Although the operational aspects of CR are being explored widely, its security aspects have gained little attention. In this survey, we p...

Software-defined radio (SDR), software radio (SWR), and cognitive radio (CR) are futuristic concepts that promise to significantly impact wireless communications technologies. Today, however, technology ironically is one of the limiting factors in the production of a true software radio that is capable of dynamically reconfiguring itself to meet user requirements or spectral limitations. Specif...

There is a rapid advancement in wireless communication technology providing the network services anywhere and anytime. 4G communication systems are being developed to solve the various problems the current communication systems (3G, 2.5G) are facing.4G will be an intelligent technology that will reduce the number of different technologies to a single global standard. Cognitive Radio (CR) is the...