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With the increase in utilization of portable devices and ever-growing demand for greater data rates in wireless transmission, an increasing demand for spectrum channels was observed since last decade. Currently, radio spectrum channels are assigned for quite long time periods to licensed subscribers who may not constantly use these bands, which leads to an inefficient use of the radio spectrum. The...
Signal classification plays an important role in spectrum sensing for cognitive radios to identify and avoid interference from other wireless devices. In this paper, we study a network of cognitive radios that jointly perform signal classification via cooperation. We propose a simple but effective linear cooperation scheme to fuse pre-processed measurements collected from spatially distributed cognitive...
Cooperative spectrum sensing has proved its efficiency in cognitive radio networks. One of the key element of cooperative spectrum sensing is data fusion, which performs at fusion center. It is the process of combining local sensing data for hypothesis testing. In this paper a scheme of combining local sensing information based on correlation has been proposed. The simulation results shows that square...
The presence of the primary signal changes not only the signal energy but also the correlation structure, a new spectrum sensing algorithm based on the determinant of the sample covariance matrix is then introduced. The new algorithm utilizes the fact that the determinant of the sample covariance matrixes of received signals is different from that of noise samples with high probability to detect whether...
Cooperative spectrum sensing for cognitive radio (CR) networks has been widely studied to increase the reliability of the primary user detection. However, when there are a large number of cooperating CRs, this typically leads to an increase in overhead in sensing reporting as well as in sensing report combining. A large number of CRs participating in cooperative spectrum sensing also increases the...
As the first step of cognitive radio, spectrum sensing is one of the most important technologies which find the available spectrum for the cognitive users. At present, the promising OFDM techniques are widely used in many wireless communication systems. As a result, sensing the existence of OFDM signals becomes vital for CR system. For this, a cyclostationary statistical test based on spectrum sensing...
The demand for wireless communication has grown remarkably in the last year, consequently raising the problem of spectrum scarcity. In this context, cognitive radio is an emerging technology that aims to overcome that scarcity, which is one of the most challenging problems in modern wireless communication. Among its fundamental function, the most important is the spectrum sensing which require precise...
The demand for wireless communication has grown remarkably in the last year, consequently raising the problem of spectrum scarcity. In this context, cognitive radio is an emerging technology that aims to overcome that scarcity which is one of the most challenging problems in modern wireless communication. Among its fundamental function, the most important is the spectrum sensing which require precise...
In this paper, we investigate the performance of a general multi-layer decentralized system setup for cooperative spectrum sensing, which includes realistic sensing/reporting channels and correlated log-normal shadow-fading in all wireless links of the cooperative network. Our investigations will show that, even though often overlooked in typical cooperative spectrum sensing analysis, shadowing correlation...
Spectrum sensing is the necessary function to achieve spectrum sharing. Distributed and collaborative spectrum sensing can improve the sensing credibility greatly, however when there are too many sensing nodes in the cognitive radio system, for example IEEE802.22 Wireless Regional Area Network system, it will produce large signaling overhead. To reduce the signaling overhead, the selection of sensing...
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