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China Communications 2018年第6期15卷 98-108页

作者： Mei Rong Department of Electronic and Information Engineering Chang'an University

Interference alignment(IA) is suitable for cognitive radio networks(CRNs).However, in IA spectrum sharing(SS) process of general underlay CRNs, transmit power of cognitive radio transmitters usually should be reduced to satisfy interference constraint of primary user(PU), which may lead to low signalto-noise-ratio at cognitive radio receivers(CRRs). Consequently, sum rate of cognitive users(CUs) may fall short of the theoretical maximum through IA. To solve this problem,we propose an adaptive IA SS method for general distributed multi-user multi-antenna CRNs. The relationship between interference and noise power at each CRR is analyzed according to channel state information, interference requirement of PU, and power budget of CUs. Based on the analysis, scenarios of the CRN are classified into 4 cases, and corresponding IA SS algorithms are properly designed. Transmit power adjustment, CU access control and adjusted spatial projection are used to realize IA among CUs. Compared with existing methods, the proposed method is more general because of breaking the restriction that CUs can only transmit on the idle sub-channels. Moreover, in comparison to other five IA SS methods applicable in general CRN, the proposed method leads to improved achievable sum rate of CUs while guarantees transmission of PU.

关键词： cognitive radio networks spectrum sharing interference alignment scenario classification

Non-saturated throughput analysis of IEEE 802.11-based cognitive radio networks

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The Journal of China Universities of Posts and Telecommunications 2012年第6期19卷 6-13页

作者： ZHAO Yuan JIN Shun-fu TIAN Nai-shuo College of Information Science and Engineering Yanshan University College of Science Yanshan University

Technology of cognitive radio networks has emerged as an effective method to enhance the utilization of the radio spectrum where the primary users have priority to use the spectrum, and the secondary users try to exploit the spectrum unoccupied by the primary users. In this paper, considering the non-saturated condition, the performance analysis for the IEEE 802.11-based cognitive radio networks is presented with single-channel and multi-channel, respectively. For the single-channel case, an absorbing Markov chain model describing the system transitions is constructed, and one-step transition probability matrix of the Markov chain is given. By using the method of probability generating function, the non-saturated throughput of the secondary users is obtained. For the multi-channel case, taking into account the negotiation-based sensing policy, the mean number of unused channels perceived by the second users is given, and then the non-saturated aggregate throughput of the secondary users is derived. Finally, numerical examples are provided to show the influences of the non-saturated degree, the number of the secondary users and the channel utilization of the primary users on the performance measures for the non-saturated throughput with single-channel and the non-saturated aggregate throughput with multi-channel.

关键词： cognitive radio networks IEEE 802.11 non-saturated throughput absorbing Markov chain probability generating function

Energy-Efficient Target Channel Sequence Design for Spectrum Handoffs in cognitive radio networks

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China Communications 2017年第5期14卷 207-217页

作者： Xiaolong Yang Xuezhi Tan Chongqing Key Lab of Mobile Communications Technology Chongqing University of Posts and TelecommunicationsChongqing 400065China Communication Research Centre.Harbin Institute of Technology Harbin 150080China

cognitive radio is considered as an efficient way to improve the spectrum efficiency. As one of its key technologies,spectrum handoff can guarantee the transmission continuity of secondary users(SUs). In this paper,we address a new and more generalized spectrum handoff problem in cognitive radio networks(CRNs),by considering simultaneously energy efficiency,multiple spectrum handoffs and multiple channels. Furthermore,effects of the primary users'(PUs')arrival and service rate on the target channel sequence selection are also considered. In order to obtain the energy-efficient target channel sequence,we firstly analyze the energy consumption and the number of delivered bits per hertz in the spectrum handoff process,and formulate a ratio-type energy efficiency optimization problem,which can be transformed into a parametric problem by utilizing fractional programming. Then,we propose an algorithm combining dynamic programming with bisection(DPB)algorithm to solve the energy efficiency optimization problem. Our simulation results verify that the designed target channel sequence has better performance than the existing algorithms in terms of energy efficiency.

关键词： energy efficiency spectrum handoff: fractional programming cognitive radio networks

Cooperative Jamming for Enhancing Security of cognitive radio networks with Multiple Primary Users

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China Communications 2017年第7期14卷 93-107页

作者： Xiaofeng Feng Xinbo Gao Ru Zong State Key Laboratory of Integrated Services networks School of Electronic Engineering Xidian University

In cognitive radio networks(CRNs), through recruiting secondary user(SU) as friendly jammer, the secrecy rate obtained by primary user(PU) can be improved. Previous work only considered a simple scenario with a single PU in their frameworks. In this paper, we will consider a more complicated scenario with multiple PUs and try to investigate the cooperative jamming between multiple PUs and a single SU. When there are multiple PUs in CRN, in order to obtain more spectrum for data transmission, SU will cooperate with multiple PUs at the same time. Considering that both PU and SU are rational and selfish individuals, the interaction between PUs and SU is formulated as a multi-leaders and single-follower Stackelberg game, wherein PU is the leader and SU is the follower. And the Stackelberg Equilibrium(SE) is considered as the final decisions accepted by all PUs and SU. Furthermore, we also prove that when a specific condition is satisfied, the existence of SE can be guaranteed. And a Gauss-Jacobi iterative algorithm is proposed to compute a SE. Finally, simulation results are given to verify the performance and demonstrate that both of the PUs' secrecy rate and the SU's transmission rate can be improved through cooperation.

关键词： cognitive radio networks cooperative jamming physical layer security spectrum sharing stackelberg game

Energy Efficiency-Based Decision Making in cognitive radio networks

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China Communications 2016年第11期13卷 205-213页

作者： Hongning Li Qingqi Pei Leilei Xu State Key Laboratory of Integrated Services networks Xidian University School of Telecommunications Engineering Xidian University

As a constraint for smart devices,energy consumption has attract people's attention for a long time period. How to get higher resource utilization with less energy consumption is a challenge for cognitive radio networks. Secondary users have to participate in spectrum sensing at the cost of energy and access idle spectrum without interfering primary users. However,not all participating secondary users can access idle spectrum. How to ensure the participation users access spectrum efficiently with a larger probability is an urgent problem to be solved. We propose an Energy Efficiency-based Decision Making(EEDM) for cognitive radio networks,which fully considers residual energy and probability of obtaining spectrum resources. Simulation and analysis show that the proposed scheme can maximize proportion of allocated users under the premise of ensuring the accuracy of spectrum sensing,then balance users' energy consumption and access efficiency,so as to effectively improve the utilization of spectrum resources.

关键词： cognitive radio networks spectrum sensing energy efficiency decision making

Securing Privacy Using Optimization and Statistical Models in cognitive radio networks

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Computer Systems Science & Engineering 2022年第8期42卷 523-533页

作者： R.Neelaveni B.Sridevi J.Sivasankari Department of Electronics and Communication Engineering MNM Jain Engineering CollegeChennai60009India Department of Electronics and Communication Engineering Velammal Institute of TechnologyChennai602001India Department of Electronics and Communication Engineering Ultra College of Engineering and TechnologyMadurai625104India

cognitive radio networks(CRN)are the possible and ideal solution for meeting the spectrum needs of next-generation communication *** is a promising alternative approach that allows spectrum sharing in many *** licensed users considered Primary Users(PU)and unlicensed users as Secondary Users(SU).Time and power consumption on security issues are considered degrading factors in performance for improving the Quality of Service(QoS).Irrespective of using different optimization techniques,the same methodology is to be updated for the *** that,learning and optimization go hand in *** ensures the security in CRN,risk factors in spectrum sharing to SU for secure *** objective of the proposed work is to preserve the location of the SU from attackers and attain the clustering of SU to utilize the *** Colony Optimization(ACO)is implemented to increase the overall efficiency and utilization of the *** is used to form clusters of SUs in the co-operative spectrum sensing *** paper deals with threat detection and classifying threats using parameters such as unlikability,context privacy,anonymity,conditional traceability,and *** this privacy-preserving model,overall accuracy is 97.4%,and it is 9%higher than the conventional models without Privacy-Preserving Architecture(PPA).

关键词： Attacks secondary users cognitive radio networks security

Optimal resource allocation scheme for cognitive radio networks with relay selection based on game theory

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The Journal of China Universities of Posts and Telecommunications 2012年第6期19卷 25-28,62页

作者： ZHAI Lan-jie JI Hong LI Xi TANG Yi-wen School of Information and Communication Engineering Beijing University of Posts and Telecommunications

In this paper, we present a non-transferable utility coalition graph game （NTU-CGG） based resource allocation scheme with relay selection for a downlink orthogonal frequency division multiplexing （OFDMA） based cognitive radio networks to maximize both system throughput and system faimess. In this algorithm, with the assistance of others SUs, SUs with less available channels to improve their throughput and fairness by forming a directed tree graph according to spectrum availability and traffic demands of SUs. So this scheme can effectively exploit both space and frequency diversity of the system. Performance results show that, NTU-CGG significantly improves system faimess level while not reducing the throughput comparing with other existing algorithms.

关键词： cooperative relaying cognitive radio networks relay selection and resource allocation coalition graph game

Power Control and Routing Selection for Throughput Maximization in Energy Harvesting cognitive radio networks

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Computers, Materials & Continua 2020年第6期63卷 1273-1296页

作者： Xiaoli He Hong Jiang Yu Song Muhammad Owais School of Information Engineering South West University of Science and TechnologyMianyang621010China School of Computer Science Sichuan University of Science and EngineeringZigong643000China Department of Network Information Management Center Sichuan University of Science and EngineeringZigong643000China Alhamd Islamic University BalochistanPakistan

This paper investigates the power control and routing problem in the communication process of an energy harvesting(EH)multi-hop cognitive radio network(CRN).The secondary user(SU)nodes(i.e.,source node and relay nodes)harvest energy from the environment and use the energy exclusively for transmitting *** SU nodes(i.e.,relay nodes)on the path,store and forward the received data to the destination *** consider a real world scenario where the EH-SU node has only local causal knowledge,i.e.,at any time,each EH-SU node only has knowledge of its own EH process,channel state and currently received *** order to study the power and routing issues,an optimization problem that maximizes path throughput considering quality of service(QoS)and available energy constraints is *** solve this optimization problem,we propose a hybrid game theory routing and power control algorithm(HGRPC).The EH-SU nodes on the same path cooperate with each other,but EH-SU nodes on the different paths compete with each *** selecting the best next hop node,we find the best strategy that can maximize *** addition,we have established four steps to achieve routing,i.e.,route discovery,route selection,route reply,and route *** with the direct transmission,HGRPC has advantages in longer distances and higher hop *** algorithm generates more energy,reduces energy consumption and increases predictable residual *** particular,the time complexity of HGRPC is analyzed and its convergence is *** simulation experiments,the performance(i.e.,throughput and bit error rate(BER))of HGRPC is ***,experimental results show that HGRPC has higher throughput,longer network life,less latency,and lower energy consumption.

关键词： cognitive radio networks power control routing selection energy harvesting game theory amplify-and-forward(AF) throughput

Optimal spectrum allocation of primary users in light-handed cognitive radio networks

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Journal of Harbin Institute of Technology(New Series) 2012年第3期19卷 21-27页

作者：司鹏博孙恩昌张延华 College of Electronic Information and Control Engineering Beijing University of Technology College of Electronic Information and Control Engineering Beijing University of Technology100124 BeijingChina

In traditional cognitive radio(CR) network,secondary users(SUs) are always assumed to obey the rule of"introducing no interference to the primary users(PUs) ".However,this assumption may be not realistic as the CR devices becoming more and more intelligent *** this paper,with the concept of lighthanded CR,which is proposed to deal with the above mentioned problem by enforcing"punishment"to illegal CR transmissions,the action decisions of primary users(PUs) are modeled as a partially observable Markov decision process(POMDP),and the optimal spectrum allocation scheme with the objective of maximizing their reward is proposed,which is defined by the utility ***,a reduced scheme with much smaller state space has been proposed in this paper for lower computational *** simulation results show that the proposed schemes improve the reward significantly compared to the existing scheme.

关键词： cognitive radio networks light-handed CR optimal decision making POMDP

Detection time analysis for the multiple-user cooperative spectrum sensing scheme in cognitive radio networks

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Science in China(Series F) 2009年第10期52卷 1915-1925页

作者： ZHU Jia ZHENG BaoYu ZOU YuLong Institute of Signal Processing and Transmission Nanjing University of Posts and Telecomm Nanjing 210003 China

In this paper, a novel multiple-user cooperative spectrum sensing （MCSS） scheme is proposed to achieve the spatial diversity gains for cognitive radio （CR） networks, where only the best relay, selected among all the candidate relays in accordance with the quality of channel conditions, is utilized to cooperatively detect the primary user. Closed-form expressions of detection time for the traditional non-cooperative and the proposed MCSS schemes are derived over Rayleigh fading channels. In addition, numerical experimentations are conducted to make a performance comparison between the noncooperative sensing and our scheme. The result shows that by exploiting the multiple-user cooperation, the detection time is reduced greatly and moreover, diversity gains obtained by the MCSS scheme increase with a rise in the number of candidate relays.

关键词： cognitive radio networks multiple-user cooperation spectrum sensing cooperative diversity