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  • Open Access

    ARTICLE

    Improved Channel Allocation Scheme for Cognitive Radio Networks

    Shahzad Latif1, Suhail Akraam2, Arif Jamal Malik3, Aaqif Afzaal Abbasi3, Muhammad Habib3, Sangsoon Lim4,*

    Intelligent Automation & Soft Computing, Vol.27, No.1, pp. 103-114, 2021, DOI:10.32604/iasc.2021.014388

    Abstract

    In recent years, wireless channel optimization technologies witnessed tremendous improvements. In this regard, research for developing wireless spectrum for accommodating a wider range of wireless devices increased. This also helped in resolving spectrum scarcity issues. Cognitive Radio (CR) is a type of wireless communication in which a transceiver can intelligently detect which communication channels are being used. To avoid interference, it instantly moves traffic into vacant channels by avoiding the occupied ones. Cognitive Radio (CR) technology showed the potential to deal with the spectrum shortage problem. The spectrum assignment is often considered as a key research challenge in Cognitive Radio… More >

  • Open Access

    ARTICLE

    Spectrum Allocation for Cognitive Radio Networks Using the Fireworks Algorithm

    Zhou Feng, Xue Weilian*

    Computer Systems Science and Engineering, Vol.33, No.4, pp. 275-286, 2018, DOI:10.32604/csse.2018.33.275

    Abstract The fireworks algorithm features a small number of parameters, remarkable optimization ability, and resistance to a local optimum. Based on the graph coloring model, the fireworks algorithm is introduced for the first time to solve the spectrum allocation problem for cognitive radio networks, thus maximizing utility and fairness of spectrum allocation. Two-layer binary coding is adopted for individual fireworks. The first layer refers to the coding of cognitive users used to determine channels that can be connected with the user. The second layer refers to the auxiliary coding of channels responsible for addressing mutual interference among multiple cognitive users when… More >

  • Open Access

    ARTICLE

    An Efficient Optimized Handover in Cognitive Radio Networks Using Cooperative Spectrum Sensing

    H. Anandakumara, K. Umamaheswarib

    Intelligent Automation & Soft Computing, Vol.24, No.4, pp. 843-849, 2018, DOI:10.1080/10798587.2017.1364931

    Abstract Cognitive radio systems necessitate the incorporation of cooperative spectrum sensing among cognitive users to increase the reliability of detection. We have found that cooperative spectrum sensing is not only advantageous, but is also essential to avoid interference with any primary users. Interference by licensed users becomes a chief concern and issue, which affects primary as well as secondary users leading to restrictions in spectrum sensing in cognitive radios. When the number of cognitive users increases, the overheads of the systems, which are meant to report the sensing results to the common receiver, which becomes massive. When the spectrum, which is… More >

  • Open Access

    ARTICLE

    Power Control and Routing Selection for Throughput Maximization in Energy Harvesting Cognitive Radio Networks

    Xiaoli He1, 2, Hong Jiang1, *, Yu Song1, 3, Muhammad Owais4

    CMC-Computers, Materials & Continua, Vol.63, No.3, pp. 1273-1296, 2020, DOI:10.32604/cmc.2020.09908

    Abstract 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 data. The SU nodes (i.e., relay nodes) on the path, store and forward the received data to the destination node. We 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… More >

  • Open Access

    ARTICLE

    Analysis of Underlay Cognitive Radio Networks Based on Interference Cancellation Mechanism

    Lei Wang1, Jian Liu1, Changming Zhao2, 3, *, Alan Yang4

    CMC-Computers, Materials & Continua, Vol.63, No.1, pp. 401-416, 2020, DOI:10.32604/cmc.2020.06680

    Abstract In this paper, we investigate the performance of secondary transmission scheme based on Markov ON-OFF state of primary users in Underlay cognitive radio networks. We propose flexible secondary cooperative transmission schemewith interference cancellation technique according to the ON-OFF status of primary transmitter. For maximal ratio combining (MRC) at destination, we have derived exact closed-form expressions of the outage probability in different situations. The numerical simulation results also reveal that the proposed scheme improve the secondary transmission performance compared with traditional mechanism in terms of secondary outage probability and energy efficiency. More >

  • Open Access

    ARTICLE

    Performance Analysis of Relay Based NOMA Cooperative Transmission under Cognitive Radio Network

    Yinghua Zhang1, 2, Jian Liu1, *, Yunfeng Peng1, Yanfang Dong2, Guozhong Sun2, Hao Huang3, Changming Zhao4, 5

    CMC-Computers, Materials & Continua, Vol.63, No.1, pp. 197-212, 2020, DOI:10.32604/cmc.2020.07059

    Abstract This paper proposes a hybrid spectrum accessing mechanism by using NOMA-based cooperative transmission and beam-forming technology. In this mechanism, the secondary user employs spectrum-sensing technology to detect the existence of the primary user. If the primary user does not exist, the secondary source user directly transmits data to the destination user. If the primary user exists, the secondary source user finds the optimal relay according to certain selection principle before transmitting data to the destination user through the chosen relay node. For the signal receiving stage, the secondary user takes use of beam-forming technology to receive the signal from both… More >

  • Open Access

    ARTICLE

    Intelligent Spectrum Detection Model Based on Compressed Sensing in Cognitive Radio Network

    Yanli Ji1, *, Weidong Wang2, Yinghai Zhang2

    CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.2, pp. 691-701, 2020, DOI:10.32604/cmes.2020.07861

    Abstract In view of the uncertainty of the status of primary users in cognitive networks and the fact that the random detection strategy cannot guarantee cognitive users to accurately find available channels, this paper proposes a joint random detection strategy using the idle cognitive users in cognitive wireless networks. After adding idle cognitive users for detection, the compressed sensing model is employed to describe the number of available channels obtained by the cognitive base station to derive the detection performance of the cognitive network at this time. Both theoretical analysis and simulation results show that using idle cognitive users can reduce… More >

  • Open Access

    ARTICLE

    Analysis of Underlay Cognitive Radio Networks Based on Interference Cancellation Mechanism

    Lei Wang1, Jian Liu1,*, Alan Yang2

    Journal of Information Hiding and Privacy Protection, Vol.1, No.3, pp. 119-133, 2019, DOI:10.32604/jihpp.2019.07296

    Abstract In this paper, we study the state-dependent interference channel, where the Rayleigh channel is non-causally known at cognitive network. We propose an active secondary transmission mechanism with interference cancellation technique according to the ON-OFF status of primary network. the secondary transmission mechanism is divided into four cases according to the active state of the primary user in the two time slots. For these interference cases, numerical results are provided to show that active interference cancellation mechanism significantly reduces the secondary transmission performance in terms of secondary outage probability and energy efficiency. More >

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