Optimal number of secondary users for cooperative sensing in cognitive radio networks

2009 ◽  
Author(s):  
Lei Zhang ◽  
Ding Zhang ◽  
Guangming Huang
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Networks ◽  
Radio Networks ◽  
Optimal Number ◽  
Cooperative Sensing ◽  
Secondary Users

scholarly journals Performance Analysis of Cooperative Spectrum Sensing under Guaranteed Throughput Constraints for Cognitive Radio Networks

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
H. F. Al-Doseri ◽  
M. A. Mangoud
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Networks ◽  
Cooperative Spectrum Sensing ◽  
Primary User ◽  
Radio Networks ◽  
Probability Of Detection ◽  
Cooperative Sensing ◽  
Soft Decision ◽  
Secondary Users ◽  
Sensing Time

One of the main challenges in cognitive radio networks is the ability of secondary users to detect the primary user presence with high probability of detection. In previous research, optimizing cooperative sensing in cognitive radio networks is performed for either a targeted probability of detection or a false alarm. After setting one of the probabilities as an optimization constraint, the other is optimized. In this paper, a guaranteed constant throughput at the secondary users is introduced as a target while optimizing probability of detection for cooperative sensing. Both sensing time values and number of cooperated cognitive radio secondary users are investigated to maximize the probability of detection of primary user. AND and OR hard decision schemes are considered and compared with soft decision scheme which is weighted modified deflection coefficient scheme (W-MDC). It is illustrated that cooperation of all users and utilizing full frames for sensing time will not provide maximum probability of detection. A tradeoff between performances of cognitive radio networks with and without optimization is presented. The effects of varying network sizes, normalized target throughput, maximum frame duration times, and received signal-to-noise ratio at the fusion center are investigated for different fusion rules.

Operating point selection for primary and secondary users in cognitive radio networks

2009 ◽  
Vol 53 (8) ◽  
pp. 1158-1170 ◽  
Author(s):  
Xavier Gelabert ◽  
Ian F. Akyildiz ◽  
Oriol Sallent ◽  
Ramon Agustí
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Networks ◽  
Radio Networks ◽  
Operating Point ◽  
Point Selection ◽  
Secondary Users ◽  
Selection For ◽  
Primary And Secondary Users

Asynchronous Channel Allocation in Opportunistic Cognitive Radio Networks

2015 ◽  
pp. 388-426
Author(s):  
Sylwia Romaszko ◽  
Petri Mähönen
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Networks ◽  
Channel Allocation ◽  
Optimal Solution ◽  
Radio Networks ◽  
Traffic Patterns ◽  
Spectrum Access ◽  
Secondary Users ◽  
Channel Parameters ◽  
Channel Service

In the case of Opportunistic Spectrum Access (OSA), unlicensed secondary users have only limited knowledge of channel parameters or other users' information. Spectral opportunities are asymmetric due to time and space varying channels. Owing to this inherent asymmetry and uncertainty of traffic patterns, secondary users can have trouble detecting properly the real usability of unoccupied channels and as a consequence visiting channels in such a way that they can communicate with each other in a bounded period of time. Therefore, the channel service quality, and the neighborhood discovery (NB) phase are fundamental and challenging due to the dynamics of cognitive radio networks. The authors provide an analysis of these challenges, controversies, and problems, and review the state-of-the-art literature. They show that, although recently there has been a proliferation of NB protocols, there is no optimal solution meeting all required expectations of CR users. In this chapter, the reader also finds possible solutions focusing on an asynchronous channel allocation covering a channel ranking.

Security for Cognitive Radio Networks

2012 ◽  
pp. 238-256 ◽  
Author(s):  
Rajni Dubey ◽  
Sanjeev Sharma ◽  
Lokesh Chouhan
Keyword(s):  
Cognitive Radio ◽  
Wireless Network ◽  
Cognitive Radio Networks ◽  
Reference Model ◽  
Development Stage ◽  
Radio Networks ◽  
Full Duplex ◽  
Secondary Users ◽  
Wireless Communication Network ◽  
Open Systems Interconnection

Most of the frequency spectrum bands have already been licensed, and the licensed spectrum is not being utilized efficiently. Cognitive Radio Networks (CRNs) are the kind of full duplex radio that automatically altered its transmission or reception parameters, in such a way that the entire wireless communication network of which it is a node communicates efficiently, while avoiding interference with primary or secondary users. In this chapter, the authors introduce the concept of security threats that may pose a serious attack in CRN. Due to the unique characteristics of CRN, such network is highly vulnerable to security attacks compared to wireless network or infrastructure-based wireless network. The main objective of this chapter is to assist CR designers and the CR application engineers to consider the security factors in the early development stage of CR techniques. Challenges and various security issues are explored with respect to OSI (Open Systems Interconnection) reference model. Various possible and attacks are discussed broadly and respective solutions are also proposed by this chapter. Different architectures and models are also explained, and compared with the existing models.

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