Cognitive radio (CR) technology has been suggested for effective use of spectral resources. Spectrum sensing is one of the main operations of CR users to identify the vacant frequency bands. Cooperative spectrum sensing (CSS) is used to increase the performance of CR networks by providing spatial diversity. The accuracy of spectrum sensing is the most important challenge in the CSS process sinc...

in this paper, an interference management for multi-beam satellite network to enhance spectral efficiency is studied. first, a two-satellite for future generation satellite network using cognitive radio technology is provided.this network is composed of a secondary satellite and aprimary satellite where the primary satellite system does not suffer from severe destructive interferences coming fr...

We design a novel nano-ring resonator using two-dimensional photonic crystal (2D-PhC), for bio-sensing applications. The structure of biosensor is created by two-curve-shaped ring resonator which sandwiched by two waveguides. These are configured by removing one row of air holes. The refractive index of sensing hole is changed by binding an analyte. Hence, intensity of the transmission spectrum...

Cognitive radio (CR) network is an excellent solution to the spectrum scarcity problem. Cooperative spectrum sensing (CSS) has been widely used to precisely detect of primary user (PU) signals. The trustworthiness of the CSS is vulnerable to spectrum sensing data falsification (SSDF) attack. In an SSDF attack, some malicious users intentionally report wrong sensing results to cheat the fusion c...

we design a novel nano-ring resonator using two-dimensional photonic crystal (2d-phc), for bio-sensing applications. the structure of biosensor is created by two-curve-shaped ring resonator which sandwiched by two waveguides. these are configured by removing one row of air holes. the refractive index of sensing hole is changed by binding an analyte. hence, intensity of the transmission spectrum...

Cognitive Radio (CR) networks enable dynamic spectrum access and can significantly improve spectral efficiency. Cooperative Spectrum Sensing (CSS) exploits the spatial diversity between CR users to increase sensing accuracy. However, in a realistic scenario, the trustworthy of CSS is vulnerable to Spectrum Sensing Data Falsification (SSDF) attack. In an SSDF attack, some malicious CR users deli...

Spectrum sensing is an important functional unit of the cognitive radio networks. The spectrum sensing is one of the main challenges encountered by cognitive radio. This paper presents a survey of spectrum sensing techniques and they are studied from a cognitive radio perspective. The challenges that go with spectrum sensing are reviewed. Two sensing schemes, namely; cooperative sensing and eig...

collaborative spectrum sensing (css) is an effective approach to improve the detection performance in cognitive radio (cr) networks. inherent characteristics of the cr have imposed some additional security threats to the networks. one of the common threats is primary user emulation attack (puea). in puea, some malicious users try to imitate primary signal characteristics and defraud the cr user...

As the use of Cognitive Radio is increasing day by day, the problems related to spectrum sensing is also increasing. This paper presents a survey on different spectrum sensing methodologies. Furthermore, various sensing features like multi-dimensional spectrum sensing, cooperative sensing, dynamic spectrum access, external sensing algorithms and other alternative sensing methods are reviewed.