scholarly journals Spectrum-Efficient Resource Allocation in Multi-Radio Multi-Hop Cognitive Radio Networks

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4493 ◽  
Author(s):  
Bin Han ◽  
Ying Luo ◽  
Min Zeng ◽  
Hong Jiang
Keyword(s):  
Cognitive Radio ◽  
Simulation Analysis ◽  
Computational Cost ◽  
Optimal Solution ◽  
Primary User ◽  
Spectrum Efficiency ◽  
Mixed Integer ◽  
Spectrum Utilization ◽  
Long Distance ◽  
Average Spectrum

The multi-hop cognitive radio network (CRN) has attracted much attention in industry and academia because of its seamless wireless coverage by forming multi-hop links and high spectrum utilization of cognitive radio (CR) technology. Using multi-slot statistical spectrum status information (SSI), this work investigates the average spectrum efficiency (SE) of a multi-radio multi-hop (MRMH) CRN where each hop is permitted to use different spectra and long-distance hops can reuse the same idle primary user (PU) spectrum. Faced with the modeled SE problem, which is a complex non-convex fractional mixed integer nonlinear programming (MINLP) problem, the optimal spectrum and power allocation for multi-hop links in multi-slot and multi-channel scenarios can be obtained with the proposed successive multi-step convex approximation scheme (SMCA). As shown through computational complexity and simulation analysis, SMCA can obtain an approximate lower bound of the optimal solution for the modeled SE problem with a lower computational cost. Furthermore, some potential relationships between network performance and spectrum idle rate can be easily discussed with SMCA, which can provide some sensible deployment strategies for the MRMH CRN in future multi-slot scenarios.

Development of mathematical model for multi-user coded-cooperation based cognitive radio system and its outage probability analysis

2021 ◽  
Author(s):  
Garima Singh ◽  
Gurjit Kaur
Keyword(s):  
Mathematical Model ◽  
Cognitive Radio ◽  
Outage Probability ◽  
Utilization Efficiency ◽  
Spectrum Efficiency ◽  
Spectrum Utilization ◽  
Radio System ◽  
Cognitive Radio System ◽  
Temperature Constraint ◽  
Coded Cooperation

Abstract In this paper, single and multi-user coded-cooperation based cognitive radio system is developed by designing its mathematical model where both source and relay will communicate to a single destination with the help of each other. Then all possible multi-user scenarios are developed and their end-to-end outage probability (Pout) is calculated for underlay mode of cognitive radio. The performance of the system is analyzed in the form of channel gain and interference temperature constraint for Rayleigh fading channel. The proposed system concludes that the coded cooperation with cognitive radio outperform the available techniques in the form of bandwidth, diversity, spectrum utilization efficiency and also improves the quality of communication. Furthermore, the theoretical analysis of the outage probability for both system models is validated by asymptotic analysis. The proposed system can set as a standard for all those cognitive radio applications which requires better spectrum efficiency even if there is a scarcity of multiple physical antennas.

scholarly journals Energy Efficiency Design for Secure MISO Cognitive Radio Network Based on a Nonlinear EH Model

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Lei Ni ◽  
Xinyu Da ◽  
Hang Hu ◽  
Miao Zhang
Keyword(s):  
Energy Efficiency ◽  
Cognitive Radio ◽  
Optimization Problem ◽  
Optimal Solution ◽  
Primary User ◽  
Open Architecture ◽  
Maximization Problem ◽  
Transmit Beamforming ◽  
Secrecy Rate ◽  
Single Output

In this work, we investigate the secrecy energy efficiency (SEE) optimization problem for a multiple-input single-output (MISO) cognitive radio (CR) network based on a practical nonlinear energy-harvesting (EH) model. In particular, the energy receiver (ER) is assumed to be a potential eavesdropper due to the open architecture of a CR network with simultaneous wireless information and power transfer (SWIPT), such that the confidential message is prone to be intercepted in wireless communications. The aim of this work is to provide a secure transmit beamforming design while satisfying the minimum secrecy rate target, the minimum EH requirement, and the maximum interference leakage power to primary user (PU). In addition, we consider that all the channel state information (CSI) is perfectly known at the secondary transmitter (ST). We formulate this beamforming design as a SEE maximization problem; however, the original optimization problem is not convex due to the nonlinear fractional objective function. To solve it, a novel iterative algorithm is proposed to obtain the globally optimal solution of the primal problem by using the nonlinear fractional programming and sequential programming. Finally, numerical simulation results are presented to validate the performance of the proposed scheme.

scholarly journals Design of Hybrid Blind Detection Based Spectrum Sensing Technique

2020 ◽  
Vol 12 (4) ◽  
pp. 575-583
Author(s):  
V. Sharma ◽  
S. Joshi
Keyword(s):  
Cognitive Radio ◽  
Spectrum Sensing ◽  
Cooperative Spectrum Sensing ◽  
Primary User ◽  
Research Area ◽  
Detection Accuracy ◽  
Blind Detection ◽  
Spectrum Utilization ◽  
Detection Techniques ◽  
Generation Spectrum

Cognitive Radio is a boon to efficient utilization of spectrum to meet the demand of next generation. Spectrum Sensing (SS) is an active research area, essential to meet the requirement of efficient spectrum utilization as it detects the vacant bands. This paper develops a Hybrid Blind Detection (HBD) technique for cooperative spectrum sensing which combines the Energy Detector (ED) and the Anti-Eigen Value Detection (AVD) techniques together to enhance the detection accuracy of a cognitive radio. Collaboration among the cognitive users is achieved to reduce the error and hard fusion based detection is implemented to detect the existence of primary user. The detection accuracy of the design is evaluated with respect to detection probabilities and the results are examined for improvements with the traditional two stage detection techniques. Fusion rules for the cooperative environment are implemented and compared to detect majority rule suitable for the proposed design.

scholarly journals Hybrid Cognitive-Radio NOMA with Blind Transmission Mode Identification and BER Constraints

2021 ◽  
Author(s):  
Hamad Yahya ◽  
Emad Alsusa ◽  
Arafat Al-Dweik
Keyword(s):  
Cognitive Radio ◽  
Multiple Access ◽  
Side Information ◽  
Primary User ◽  
Base Station ◽  
Transmission Mode ◽  
Receiver Design ◽  
Spectrum Utilization ◽  
Power Domain ◽  
Mode Tm

<div>The synergy of nonorthogonal multiple access (NOMA) and cognitive radio (CR) can provide efficient spectrum utilization for future wireless networks and enable supporting heterogeneous quality of service (QoS) requirements. In this context, this article aims at evaluating the throughput of a downlink CR-NOMA network where the secondary user (SU) data is opportunistically multiplexed with the primary user (PU) data using power-domain NOMA. The data multiplexing process is constrained by the PU QoS requirements. The multiplexing process can be considered seamless with respect to the PU because its receiver design will generally remain unchanged. Moreover, we consider the case where the SU detects its own data by blindly identifying the adopted transmission mode (TM) at the base station, which can be PU orthogonal multiple access PU-OMA, SU-OMA, PU/SU-NOMA, and no transmission. Consequently, the network can be classified as a hybrid underlay-interweave. The detection process is considered blind because the SU does not receive side information about the adopted TM. The obtained analytical results corroborated by Monte Carlo simulation results show that the proposed CR-NOMA network can provide substantial throughput improvement over conventional NOMA networks, particularly at low signal-to-noise ratios (SNRs) because the unutilized PU spectrum can be used by the SU. Moreover, in good channel conditions the PU can tolerate some interference from the SU, which may improve the channel utilization significantly. </div><div><br></div>

A SURVEY OF IMPLEMENTATION OF OPPORTUNISTIC SPECTRUM ACCESS ATTACK WITH ITS PREVENTIVE SENSING PROTOCOLS IN COGNITIVE RADIO NETWORKS

2015 ◽  
Vol 3 (6) ◽  
pp. 389
Author(s):  
Monisha Ravi ◽  
Nisha Ravi ◽  
N. Ravi
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Networks ◽  
Primary User ◽  
Radio Spectrum ◽  
Radio Networks ◽  
Spectrum Efficiency ◽  
Network Simulator ◽  
Secondary Users ◽  
Primary User Emulation Attack ◽  
Research Areas

Recently, the expansive growth of wireless services, regulated by governmental agencies assigning spectrum to licensed users, has led to a shortage of radio spectrum. Since the FCC (Federal Communications Commissions) approved unlicensed users to access the unused channels of the reserved spectrum, new research areas seeped in, to develop Cognitive Radio Networks (CRN), in order to improve spectrum efficiency and to exploit this feature by enabling secondary users to gain from the spectrum in an opportunistic manner via optimally distributed traffic demands over the spectrum, so as to reduce the risk for monetary loss, from the unused channels. However, Cognitive Radio Networks become vulnerable to various classes of threats that decrease the bandwidth and spectrum usage efficiency. Hence, this survey deals with defining and demonstrating framework of one such attack called the Primary User Emulation Attack and suggests preventive Sensing Protocols to counteract the same. It presents a scenario of the attack and its prevention using Network Simulator-2 for the attack performances and gives an outlook on the various techniques defined to curb the anomaly.

scholarly journals Throughput Maximization by Optimizing Secondary Users in a Cooperative Cognitive Radio Network using Hard Fusion Rules

2020 ◽  
Vol 9 (7) ◽  
pp. 801-804
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Network ◽  
Cooperative Spectrum Sensing ◽  
Primary User ◽  
Spectrum Efficiency ◽  
Throughput Maximization ◽  
Radio Network ◽  
Secondary Users ◽  
Fusion Rules ◽  
Channel Throughput

Cognitive radio network is a promising technology for enabling secondary users to utilize the licensed spectrum of the primary user without causing interference. The data trans- mitted by the secondary users through primary channel without affecting the primary user is known as channel throughput. In cooperative spectrum sensing(CSS) as the number of secondary users increases the channel throughput increases which in turn reduces the spectrum efficiency due to more spectrum wastage. Therefore in this paper, channel throughput is maximized by optimizing secondary users proposed and throughput for variable secondary users for OR and AND fusion rules is investigated. The optimal secondary users is estimated mathematically and simulation results shows the variation of throughput for variable number of secondaryusers

scholarly journals Enhancement of Opportunistic Co-Occurrence of U-LTE and Wi-Fi/Iot in 5 GHz Using Cognitive Radio

2019 ◽  
Vol 8 (11) ◽  
pp. 25-31
Keyword(s):  
Cognitive Radio ◽  
Channel Allocation ◽  
Research Area ◽  
Spectrum Efficiency ◽  
Spectrum Utilization ◽  
Radio Communication ◽  
Regulatory Requirement ◽  
Unlicensed Spectrum ◽  
5 Ghz ◽  
Modern Era

In this modern era, Unlicensed Long-Term Evolution (U-LTE) is the most interested research area to enable its access in 5GHz ISM unlicensed band for increasing data rate and spectral efficiency. The major constraint for accessing these frequencies is being able to coexist with other Wi-Fi/IoT users. Such constraint has been tackled by developing Wi-Fi/IoT by using Cognitive Radio Network (CRN) with two objectives such as deploying the Listen-Before-Talk (LBT) regulatory requirement of radio communication in U-LTE and enhancing their co-existence with Wi-Fi/IoT users in a non-interference manner. However, uplink data transmission was not considered in the unlicensed spectrum usage and also the spectrum efficiency was less. Hence, in this paper, the co-occurrence between LTE and Wi-Fi/IoT using CRN is further enhanced and realized. Initially, the co-occurrence between LTE and Wi-Fi in the unlicensed spectrum is enhanced by proposing efficient spectrum utilization based on Conflict-Tolerant Channel Allocation (CTCA) algorithm that reduces the channel inconsistencies efficiently. Moreover, this algorithm is enhanced to increase the spectrum efficiency and simultaneous transmissions in the similar channel based on an enhanced Cell ON/OFF mechanism which optimizes the resource allocation. Finally, the simulation results show that the performance efficiency of the proposed system compared to the existing in terms of spectrum efficiency, throughput and transmission time delay

scholarly journals Spectrum Handoff in Cognitive Radio Networks: A Survey

2017 ◽  
Vol 10 (04) ◽  
pp. 765-772 ◽  
Author(s):  
Nisar Lala ◽  
Altaf Balkhi ◽  
G M Mir
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Networks ◽  
Primary User ◽  
Radio Networks ◽  
Spectrum Utilization ◽  
Secondary Users ◽  
Spectrum Handoff ◽  
Suitable Target ◽  
Promising Solution ◽  
Minimum Performance

Cognitive radio (CR) is a promising solution to improve the spectrum utilization by enabling unlicensed users to exploit the spectrum in an opportunistic manner. Spectrum handoff is a different type of handoff in CR necessitated by the reappearance of primary user (PU) in the licensed band presently occupied by the secondary users (SUs). Spectrum handoff procedures aim to help the SUs to vacate the occupied licensed spectrum and find suitable target channel to resume the unfinished transmission. The purpose of spectrum mobility management in cognitive radio networks is to make sure that the transitions are made smoothly and rapidly such that the applications running on a cognitive user perceive minimum performance degradation during a spectrum handoff. In this paper, we will survey the literature on spectrum handoff in cognitive radio networks.

MAC Layer Spectrum Sensing in Cognitive Radio Networks

2013 ◽  
pp. 210-230
Author(s):  
Mohamed Hamid ◽  
Abbas Mohammed
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Networks ◽  
Performance Metrics ◽  
Computational Cost ◽  
Radio Spectrum ◽  
Radio Networks ◽  
Superior Performance ◽  
Mac Layer ◽  
Spectrum Utilization ◽  
Network Nodes

Efficient use of the available licensed radio spectrum is becoming increasingly difficult as the demand and usage of the radio spectrum increases. This usage of the spectrum is not uniform within the licensed band but concentrated in certain frequencies of the spectrum while other parts of the spectrum are inefficiently utilized. In cognitive radio environments, the primary users are allocated licensed frequency bands while secondary cognitive users can dynamically allocate the empty frequencies within the licensed frequency band, according to their requested quality of service specifications. In this chapter, the authors investigate and assess the performance of MAC layer sensing schemes in cognitive radio networks. Two performance metrics are used to assess the performance of the sensing schemes: the available spectrum utilization and the idle channel search delay for reactive and proactive sensing schemes. In proactive sensing, the adapted and non-adapted sensing period schemes are also assessed. Simulation results show that proactive sensing with adapted periods provides superior performance at the expense of higher computational cost performed by network nodes.

Energy Harvesting in Cognitive Networks Using Feasible Channel Selection Assignment

2020 ◽  
Vol 13 (2) ◽  
pp. 173-182
Author(s):  
M. Balasubramanian ◽  
V. Rajamani
Keyword(s):  
Cognitive Radio ◽  
Energy Harvesting ◽  
Primary User ◽  
Spectrum Management ◽  
Cognitive Networks ◽  
Secondary User ◽  
Spectrum Efficiency ◽  
Cognitive Radio Systems ◽  
Token Passing ◽  
Radio Systems

Background: The importance of this paper is to achieve maximum spectrum efficiency and proper channel allotment between Primary and Secondary User. The licensed and unlicensed users gets promoted as the channel allotment is properly carried out. To improve energy capability and spectral proficiency consider energy collecting cognitive radio systems to update both energy feasibility and spectral viability. Energy Harvesting Provides possibility of sharing energy in wireless networks which improves the performance of channel capacity. Methods: In this paper an Token Passing algorithm is proposed that switches the channels between Primary User and Secondary User. The energy efficiency decision is taken according to when primary user is idle or not. When the primary user is idle the secondary user cannot harvest any energy and when the primary channel is occupied the secondary channel harvest energy from primary user so that the harvested energy will be used by the secondary user during channel allotment. This proposed algorithm provides energy harvesting and spectrum efficiency. Results: The result shows that the most extraordinary achievable throughput R (eh) of the energy harvesting cognitive radio. The State Transition will move from busy to idle and idle to busy which is represented as S0 and S1. The other parameters are Sensing Energy es, Sampling frequency fs, Primary Signal which accepts a noise SNR γp. As Token Passing Algorithm provides tokens for primary and secondary user it takes lesser time and achieves better throughput than the FDMA and suboptimal algorithm. Conclusion: This paper achieves the maximum spectrum efficiency and energy harvesting by properly allotting spectrum for both primary and secondary user. The primary user and secondary user and spectrum management perform the channel allotment efficiently through the idle and busy state and Token Passing Algorithm does energy harvesting. An efficient scheme is developed for allocating energy in energy harvesting cognitive radio systems.

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