Cooperative spectrum sensing (CSS) can improve the spectrum sensing performance by introducing spatial diversity in cognitive radio networks (CRNs). However, such cooperation also introduces the delay for reporting sensing data. Conventional cooperation scheme assumes that the cooperative secondary users (SUs) report their local sensing data to the fusion center sequentially. This causes the re...

Spectrum sensing is the basic and essential mechanisms of Cognitive Radio (CR) to find the unused spectrum. This paper presents an overview of CR architecture, discusses the characteristics and benefits of a CR. Energy detectionbased spectrum sensing has beenproposed and used widely because it doesn’t require transmitted signal properties, channel information, or even the type of modulation. In...

Spectrum sensing in cognitive radio networks allows secondary users to sense the unused spectrum without causing interference to primary users. Cognitive radio requires more accurate sensing results from unused portions of the spectrum. Accurate spectrum sensing techniques can reduce the probability of false alarms and misdetection. In this paper, a two-stage spectrum sensing scheme is proposed...

Ever increasing wireless services and networks results in spectrum scarcity. But already allocated spectrum is in under utilization in the current static fixed spectrum allocation method .So dynamic spectrum access is only solution for this issue .Spectrum sensing is one of the key technique in cognitive radio for dynamic spectrum access. There are many algorithm proposed for the spectrum sensi...

Cognitive radio (CR) technology aims to achieve efficient radio spectrum utilization based on overlay spectrum sharing. Therefore, one of the main requirements of CR systems is the capability to detect and sense the presence of primary transmissions. However, sensing is affected by the behavior of the wireless channel, i.e., hidden node, interference, shadowing, and fading, which may result in ...

An explosive growth in vehicular wireless applications gives rise to spectrum resource starvation. Cognitive radio has been used in vehicular networks to mitigate the impending spectrum starvation problem by allowing vehicles to fully exploit spectrum opportunities unoccupied by licensed users. Efficient and effective detection of licensed user is a critical issue to realize cognitive radio app...

Aalto University, P.O. Box 11000, FI-00076 Aalto www.aalto.fi Author Sachin Chaudhari Name of the doctoral dissertation Spectrum Sensing for Cognitive Radios: Algorithms, Performance, and Limitations Publisher School of Electrical Engineering Unit Department of Signal Processing and Acoustics Series Aalto University publication series DOCTORAL DISSERTATIONS 135/2012 Field of research Signal Pro...

An allocation of sensing and reporting times is proposed to improve the sensing performance by scheduling them in an efficient way for cognitive radio networks with cluster-based cooperative spectrum sensing. In the conventional cooperative sensing scheme, all secondary users (SUs) detect the primary user (PU) signal to check the availability of the spectrum during a fixed sensing time slot. Th...

JOINT SPATIAL-TEMPORAL SPECTRUM SENSING AND COOPERATIVE RELAYING FOR COGNITIVE RADIO NETWORKS Tuan T. Do, PhD George Mason University, Spring, 2011 Dissertation Director: Dr. Brian L. Mark The number of wireless systems and services has grown tremendously over the last two decades. As a result, the availability of wireless spectrum has become extremely limited. Cognitive radio is a new techniqu...

Spectrum sensing is one of the most important tasks of each cognitive radio network. Cooperation among secondary users, by increasing the sensing accuracy can improve the network throughput, but also increases the energy consumption of cognitive radio network. In this paper, we propose the reliable data combining method for cooperative spectrum sensing, according to which the fusion center by u...