Spectrum sensing is a critical functionality of Cognitive Radio(CR) systems. There are number of spectrum sensing techniques. One of techniques is energy detection. Energy detection is the simplest detection method and is the most commonly used. But, energy detection has a hidden terminal problem in real wireless communication, because of SU can be affected by frequency fading and shadowing. Co...

Cognitive radio is a novel technology that can potentially improve the utilization efficiency of the radio spectrum. Spectrum sensing is the key component of cognitive radio technology. However, detection is compromised when a user experiences shadowing or fading effects. In such cases, user cannot distinguish between an unused band and a deep fade. Thus, cooperative spectrum sensing is propose...

The ever growing wireless technologies has put a lot of demand on the usage of available spectrum, thus leading to spectrum underutilization and scarcity. To address this issue and improve spectrum utilization gave rise to the concept of the cognitive radio. The cognitive radio is known to enhance the utilization of spectrum of where a secondary user can utilize the spectrum of the primary user...

Radio frequency spectrum is a quite limited resource. With the increased dependence on modern wireless devices, the management and proper utilization of the spectrum has become a major challenge. The concept of cognitive radio aims to overcome these problems by helping to achieve improved spectral management, utilization, and efficiency. To sense the unoccupied spectrum gap is one of the essent...

This paper reviews applications of fuzzy logic to telecommunications and proposes a novel fuzzy combining scheme for cooperative spectrum sensing in cognitive radio systems. A summary of previous applications of fuzzy logic to telecommunications is given outlining also potential applications of fuzzy logic in future cognitive radio systems. In complex and dynamic operational environments, futur...

Spectrum sensing is the key component of cognitive radio technology. Spectrum sensing is a tough task because of shadowing, fading, and time-varying nature of wireless channels. However, detection is compromised when a user experiences shadowing or fading effects. In such cases, user cannot distinguish between an unused band and a deep fade. Thus, cooperative spectrum sensing is proposed to opt...

Spectrum sensing is one of the key elements in the establishment of cognitive radio. One of the most effective approaches for spectrum sensing is cyclostationary feature detection. Since modulated signals can be modeled as cyclostationary random signals, this feature can be used to recognize the cyclostationary modulated signal in a background of stationary noise even at low SNR regimes. This c...

Spectrum sensing techniques are envisaged to solve the problems in wireless networks resulting from the limited available spectrum and the inefficiency in the spectrum usage. In this paper various Spectrum Sensing Techniques like Energy Detection, Matched Filter, Cyclo-stationary Detection, Wavelet Detection are compared. The best one is evaluated for its performance. Then Cooperative Spectrum ...

Effective spectrum sensing strategies enable cognitive radios to enhance the spectrum efficiency. In this paper, modeling, performance analysis, and optimization of spectrum handoff in a centralized cognitive radio network are studied. More specifically, for a given sensing order, the average throughput of secondary users and average interference level among the secondary and primary users are ...

In cognitive radio networks, cognitive users can be coordinated to perform cooperative spectrum sensing so as to detect the primary user more accurately. In this paper, a hybrid cooperative spectrum sensing method is investigated to improve the sensing performance by exploiting double-fusion approach. In special, data fusion and decision fusion are both studied. For the first stage, cognitive u...