scholarly journals Interference Spreading through Random Subcarrier Allocation Technique and Its Error Rate Performance in Cognitive Radio Networks

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5700
Author(s):  
Amit Kachroo ◽  
Adithya Popuri ◽  
Mostafa Ibrahim ◽  
Ali Imran ◽  
Sabit Ekin
Keyword(s):  
Cognitive Radio ◽  
Error Rate ◽  
Orthogonal Frequency Division Multiplexing ◽  
Random Allocation ◽  
Secondary Users ◽  
Interference Temperature ◽  
Primary Users ◽  
Relationship Of ◽  
The Relationship ◽  
Ber Performance

In this letter, we investigate the idea of interference spreading and its effect on bit error rate (BER) performance in a cognitive radio network (CRN). The interference spreading phenomenon is caused because of the random allocation of subcarriers in an orthogonal frequency division multiplexing (OFDM)-based CRN without any spectrum-sensing mechanism. The CRN assumed in this work is of underlay configuration, where the frequency bands are accessed concurrently by both primary users (PUs) and secondary users (SUs). With random allocation, subcarrier collisions occur among the carriers of primary users (PUs) and secondary users (SUs), leading to interference among subcarriers. This interference caused by subcarrier collisions spreads out across multiple subcarriers of PUs rather than on an individual PU, therefore avoiding high BER for an individual PU. Theoretical and simulated signal to interference and noise ratio (SINR) for collision and no-collision cases are validated for M-quadrature amplitude modulation (M-QAM) techniques. Similarly, theoretical BER performance expressions are found and compared for M-QAM modulation orders under Rayleigh fading channel conditions. The BER for different modulation orders of M-QAM are compared and the relationship of average BER with interference temperature is also explored further.

Interference Modeling and Analysis in Cognitive Radio Networks

2013 ◽  
Vol 4 (4) ◽  
pp. 1-15
Author(s):  
Yanxiao Zhao ◽  
Bighnaraj Panigrahi ◽  
Kazem Sohraby ◽  
Wei Wang
Keyword(s):  
Cognitive Radio ◽  
Spectrum Sensing ◽  
Cognitive Radio Networks ◽  
Critical Role ◽  
Radio Networks ◽  
Secondary Users ◽  
Idle State ◽  
Modeling And Analysis ◽  
Interference Modeling ◽  
Primary Users

Cognitive radio networks (CRNs) have received considerable attention and viewed as a promising paradigm for future wireless networking. Its major difference from the traditional wireless networks is that secondary users are allowed to access the channel if they pose no harmful interference to primary users. This distinct feature of CRNs has raised an essential and challenging question, i.e., how to accurately estimate interference to the primary users from the secondary users? In addition, spectrum sensing plays a critical role in CRNs. Secondary users have to sense the channel before they transmit. A two-state sensing model is commonly used, which classifies a channel into either busy or idle state. Secondary users can only utilize a channel when it is detected to be in idle state. In this paper, we tackle the estimation of interference at the primary receiver due to concurrently active secondary users. With the spectrum sensing, secondary users are refrained from transmitting once an active user falls into their sensing range. As a result, the maximum number of simultaneously interfering secondary users is bounded, typically ranging from 1 to 4. This significant conclusion considerably simplifies interference modeling in CRNs. The authors present all the cases with possible simultaneously interfering secondary users. Moreover, the authors derive the probability for each case. Extensive simulations are conducted and results validate the effectiveness and accuracy of the proposed approach.

QoS Maintenance in Cognitive Radio Networks with Priority-Supporting Novel Channel Allocation Method

2019 ◽  
Vol 15 (1) ◽  
pp. 1-16
Author(s):  
K. Annapurna ◽  
B. Seetha Ramanjaneyulu
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Networks ◽  
Channel Allocation ◽  
Radio Networks ◽  
Secondary Users ◽  
Primary Users ◽  
Maximum Value ◽  
Blocking Probabilities ◽  
Bid Price

Satisfying the Quality of Service (QoS) is often a challenge in cognitive radio networks, because they depend on opportunistic channel accessing. In this context, appropriate pricing of vacant channels that is linked to the preference in their allocation, is found to be useful. However, ambiguity on the possible price at which the channel would be allotted is still a concern. In this work, an auction mechanism in which maximum value of the bid is predefined is proposed. With this, users quote their bid values as per their needs of getting the channels, up to the predefined maximum allowed bid price. However, final price of allocation is decided based on the sum total demand from all the users and the availability of vacant channels. Performance of the system is found in terms of blocking probabilities of secondary users and revenues to primary users. The proposed system is found to yield similar quantum of revenues as that of the Generalized Second Price (GSP) auction, while offering much lesser blocking probabilities to high-priority users to satisfy their QoS requirements.

scholarly journals Spectrum sensing in cognitive radio wireless networks for orthogonal freqnency division multiplexing in additive white Gaussian noise channel

2017 ◽  
Vol 1 (T4) ◽  
pp. 180-186
Author(s):  
Tri Minh Nguyen ◽  
Tu Thanh Nguyen ◽  
Phuong Huu Nguyen
Keyword(s):  
Cognitive Radio ◽  
Gaussian Noise ◽  
Orthogonal Frequency Division Multiplexing ◽  
Additive White Gaussian Noise ◽  
Sliding Window ◽  
White Gaussian Noise ◽  
Frequency Division ◽  
Low Snr ◽  
Primary Users ◽  
Ofdm Signals

Cognitive radio (CR) systems are one of the most interesting topics in recent years. They would enable more efficient use of the spectrum. The main problem of CR is how to dectect exactly the spectrum usage of primary users. There are many ways to do this, such as energy detector (ED), Axell’s detector, the sliding window detector, etc. Among them, cyclostationarity (CS) based dection methods attracted much attention because of their better results in low-SNR regimes. This paper will propose a method based on the autocorrelation property of orthogonal frequency division multiplexing (OFDM) signals in additive white Gaussian noise (AWGN).

scholarly journals Bio-inspired route estimation in cognitive radio networks

2020 ◽  
Vol 10 (3) ◽  
pp. 3095
Author(s):  
Miguel Tuberquia ◽  
Hans Lopez-Chavez ◽  
Cesar Hernandez
Keyword(s):  
Cognitive Radio ◽  
Ant Colony Optimization ◽  
Cognitive Radio Networks ◽  
Radio Networks ◽  
Ant Colony ◽  
Secondary Users ◽  
Mobility Spectrum ◽  
Hybrid Strategy ◽  
Primary Users ◽  
Specific Radio

Cognitive radio is a technique that was originally created for the proper use of the radio electric spectrum due its underuse. A few methods were used to predict the network traffic to determine the occupancy of the spectrum and then use the ‘holes’ between the transmissions of primary users. The goal is to guarantee a complete transmission for the second user while not interrupting the trans-mission of primary users. This study seeks the multifractal generation of traffic for a specific radio electric spectrum as well as a bio-inspired route estimation for secondary users. It uses the MFHW algorithm to generate multifractal traces and two bio-inspired algo-rithms: Ant Colony Optimization and Max Feeding to calculate the secondary user’s path. Multifractal characteristics offer a predic-tion, which is 10% lower in comparison with the original traffic values and a complete transmission for secondary users. In fact, a hybrid strategy combining both bio-inspired algorithms promise a reduction in handoff. The purpose of this research consists on deriving future investigation in the generation of multifractal traffic and a mobility spectrum using bio-inspired algorithms.

Towards Security Issues and Solutions in Cognitive Radio Networks

2015 ◽  
pp. 813-834
Author(s):  
Saed Alrabaee ◽  
Mahmoud Khasawneh ◽  
Anjali Agarwal
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Networks ◽  
Radio Networks ◽  
Network Technology ◽  
Spectrum Utilization ◽  
Secondary Users ◽  
Security Issues ◽  
Primary Users ◽  
Radio Technology ◽  
Cognitive Radio Technology

Cognitive radio technology is the vision of pervasive wireless communications that improves the spectrum utilization and offers many social and individual benefits. The objective of the cognitive radio network technology is to use the unutilized spectrum by primary users and fulfill the secondary users' demands irrespective of time and location (any time and any place). Due to their flexibility, the Cognitive Radio Networks (CRNs) are vulnerable to numerous threats and security problems that will affect the performance of the network. Little attention has been given to security aspects in cognitive radio networks. In this chapter, the authors discuss the security issues in cognitive radio networks, and then they present an intensive list of the main known security threats in CRN at various layers and the adverse effects on performance due to such threats, and the current existing paradigms to mitigate such issues and threats. Finally, the authors highlight proposed directions in order to make CRN more authenticated, reliable, and secure.

Introduction to Cognitive Radio Networks

2013 ◽  
pp. 1-30 ◽  
Author(s):  
Natarajan Meghanathan
Keyword(s):  
Cognitive Radio ◽  
Dynamic Spectrum Access ◽  
Dynamic Spectrum ◽  
Spectrum Access ◽  
Medium Access ◽  
Secondary Users ◽  
Comprehensive Review ◽  
Primary Users ◽  
Transmission Parameters ◽  
Perceived Availability

A cognitive radio (CR) is a radio that can change its transmission parameters based on the perceived availability of the spectrum bands in its operating environment. CRs support dynamic spectrum access and can facilitate a secondary unlicensed user to efficiently utilize the available underutilized spectrum allocated to the primary licensed users. A cognitive radio network (CRN) is composed of both the secondary users with CR-enabled radios and the primary users whose radios need not be CR-enabled. In this chapter, the authors provide an exhaustive analysis of the issues and the state-of-the-art literature solutions available with regards to the following four layers of the TCP/IP protocol layer stack, in the context of CRNs: physical layer (spectrum sensing), medium access control, routing, and transport layers. We discuss the various techniques/mechanisms/protocols that have been proposed for each of these four layers, in the context of CRNs. In addition to the above, we discuss in detail several security attacks that could be launched on CRNs and the countermeasure solutions that have been proposed to avoid or mitigate them. This chapter serves as a good comprehensive review and analysis of all the critical aspects for CRNs, and would lay a strong foundation for someone to further delve onto any particular aspect in greater depth.

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