| Cognitive radio is an exciting emerging technology that has the potential of dealing with the stringent requirement and scarcity of the radio spectrum. Such revolutionary and transforming technology represents a paradigm shift in the design of wireless systems, as it will allow the agile and efficient utilization of the radio spectrum by offering distributed terminals or radio cells the abili...

Spectrum sensing is indispensable for cognitive radio to identify the available white spaces. Energy detection is considered as a preferred technique for spectrum sensing in cognitive radio networks. It is because of its simplicity, applicability and low computational complexity, energy detection is employed widely for spectrum sensing. This paper proposes an enhanced energy detection based spe...

Cognitive radio allows unlicensed users to access licensed frequency bands through dynamic spectrum access so as to reduce spectrum scarcity. This requires intelligent spectrum sensing techniques. This paper investigates the use of cyclo-stationary detector and performance evaluation for Digital Video Broadcast-Terrestrial (DVB-T) signals. Generally, DVB-T is specified in IEEE 802.22 standard i...

Cognitive radio is an intelligent communication system which focus on dynamic spectrum usage rather than fixed spectrum assignment. Cooperative spectrum sensing is a technique for detecting the primary user accurately based on information collected from various secondary users. Energy detection technique for spectrum sensing method is employed to determine the occupancy of the frequency spectru...

The spectrum scarcity has led to rethink in the current frequency spectrum usage and develop a new concept of wireless networking. Opportunistic Spectrum Networks (OSNs) have been considered as a promising solution to the problem of spectrum shortage. In this paper, in order to compensate for the need of complex hardware, a novel and efficient Medium Access Control (MAC) framework that integrat...

In this paper, we first investigate and contrast the features of energy detection and cyclostationary feature detection for spectrum sensing. Combining the advantages of both, we propose an adaptive twostage sensing scheme which first performs spectrum sensing using an energy detector in cognitive and dynamic spectrum access networks. Then this scheme decides whether or not to implement cyclost...

Cognitive radios (CRs) have been recently emerging as prime candidates to enhance spectral efficiency by exploiting spectrum-aware systems which can reliably monitor licensed users’ activities. CR users monitor such activities by performing spectrum sensing to detect potential white spaces. However, this process of local sensing might be a challenging task in fading environments. The inefficien...

Rapidly rising energy costs and increasingly rigid environmental standards have led to an emerging trend of addressing “energy efficiency” aspect of wireless communication technologies. Cognitive radio can play an important role in improving energy efficiency in wireless networks, because from the green perspective, spectrum is a natural resource which should not be wasted but be shared. In thi...

Spectrum sensing, the problem of detecting the presence of licensed user in the channel is considered in this paper. Energy detection is best suited for the spectrum sensing when prior knowledge about the primary users is unavailable. Existing works report improved versions of energy detection which primarily focuses on maximizing the detection performance. Sensing error minimization is an impo...

Cooperative energy spectrum sensing has been proved effective to detect the spectrum holes in Cognitive Radio (CR). However, its performance may suffer from the noise uncertainty, which is portrayed by the SNR wall in some literatures. In this paper we analyze the spectrum sensing performance under noise uncertainty and find an alternative approach to obtain the SNR wall. Then the average SNR w...