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In this paper, we address the problem of routing disruption attacks in Cognitive Radio Networks (CRNs). In routing disruption attacks, the malicious node intentionally drop data packets to consume more network resources or degrade routing performance. We propose a trust management model to mitigate such attacks in CRNs. Through monitoring forwarding behaviors of secondary users (SUs), trusts of SUs...
Abstract-In cognitive radio networks, secondary users (SUs) face two conflicting objectives. Each SU seeks to minimize the sensing duration while maximizing the detection probability of primary users (PU) to avoid interfering with their transmissions. Both objectives have a substantial effect on energy efficiency. This paper investigates a noncooperative setting for selecting the sensing duration...
Selection of appropriate detection threshold (λ) is a very critical task in energy detection scheme based cognitive radio (CR) system. λ is mainly selected by using two principles called as constant detection rate (CDR) in which λ is calculated by taking fixed value of probability of detection (Pd) and constant false alarm rate (CFAR) in which λ is calculated by taking fixed value of probability of...
This paper presents a multichannel assignment problem in a centralized cognitive radio sensor network (CRSN). The basic aim of this problem is to maximize the overall system throughput and minimize the overall energy consumption of the CRSN. First, a weighted sum based optimization problem is formulated. Then the problem is represented using bipartite graph and solved using matching based hungarian...
In this paper, we consider a multi-level power allocation scheme for cognitive users in the cognitive radio networks. The proposed system uses a new frame structure to improve overall throughput of the cognitive radio systems. We propose a strategy in which, the licensed user can transmit with multiple levels of power which seems to be more realistic and practical. In this work, the proposed strategy...
In this paper, secure communication for RF-powered cognitive networks has been investigated in which the secondary source (SS) transmits confidential information to the destination (SD) using the harvested energy form primary transmitter (PT) in the presence of a passive eavesdropper (SE). Note that the transmission power at the SS is subject to two important constraint: 1) the maximum transmission...
We present a novel out-of-band spectrum sensing and channel allocation scheme for frequency hopping based cognitive radio networks using genetic algorithm. Based on the optimized solution derived from GA, a set of nodes for sensing the next hopping channel and a set of nodes for transmitting data on current channel are derived. The channel allocation is performed according to individual traffic demand...
For cognitive radio, dynamic spectrum access is a promising development direction. Dynamic spectrum access mechanism which is considered in this paper is a kind of channel reservation mechanism. Unlike most of the existing channel reservation mechanism, it is considered that the channel is reserved exclusively for unauthorized users in this paper. This reserved channel can only allow unauthorized...
Green cognitive radio has attracted significant research attention as an effective means of alleviating spectrum scarcity and energy-saving problem in wireless communications. In this paper, we focus on the power allocation for maximizing the transmission throughput and energy efficiency (EE) of secondary users (SUs). More specifically, we propose a multi-band power allocation scheme, where multiple...
In this paper, we consider the resource allocation problem in a Cognitive Radio (CR) downlink system employing both Orthogonal Frequency Division Multiple Access (OFDMA) and Multiple-Input Multiple-Output (MIMO) technologies. We aim at maximizing the total cognitive system throughput subject to the interference power constraint at the Primary Receiver (PR), the total transmission power constraint...
For the energy-constrained cognitive networks, it is particularly important to improve their energy efficiency (EE). We focus on the EE optimization of the continuous spectrum sensing (CSS). The EE of the secondary user (SU) networks is derived. To maximize the EE, an optimization problem is formulated under the constraints of sensing performance. After some theoretical analyses, the detailed processes...
Dynamic spectrum access technology is a kind of technology that provides a solution to the spectrum scarce problem. The most important issue in the CR network (both primary users and secondary users coexists in the network) is that the traffic of secondary users should not affect the primary users communication. In order to not affect the primary users, we have to detect the existence of the primary...
Cognitive radio (CR) network technology is widely used as a approach to the solve the scarce radio spectrum by allowing the unlicensed users to access the licensed spectrum. Since in the CR network, the licensed users are easily be affected by the introduce of the unlicensed user, we have to avoid to bring the interference to the licensed users when the unlicensed users try to transmit the data on...
Cognitive radio (CR) allows unauthorized users to access authorized band without interfering the authorized user, thereby improving the bandwidth efficiency. In addition, cooperative communications with relay stations (RSs) can be used to improve throughput performance of 4G downlink network. In this study a cognitive radio assisted cooperation (CRAC), which combines advantages of CR and cooperative...
Cognitive radios (CRs) use learning algorithms (LAs) located in the cognition engine (CE) to adapt their behaviour. CRs use LAs for spectrum prediction to enhance their quality of service (QoS). The CR's CE consumes battery power while classifying LAs. The LA classification reduces CR data transmission power and limits CR throughput. This paper proposes a framework to enhance CR QoS in LTE-Advanced...
Cognitive Radio (CR) has emerged as an intelligent technology to deal with spectrum scarcity. This research aims to simulate our already published research paper “DDH-MAC: A novel Dynamic De-Centralized Hybrid MAC protocol for Cognitive Radio Networks”. We have assessed the efficiency of the protocol by using a network simulation tool, OPNET 14.5 modeler. The simulation results were then compared...
A new cooperative spectrum sensing method for non-time-slotted full duplex cognitive radio networks (FD-CRNs) is proposed in this paper, with the self-interference channel considered as Nakagami-m fading channel, which is more practical compared with commonly used Rayleigh and Rice channel. Closed-form expressions of the probabilities of false alarm and detection are provided in this paper for non-time-slotted...
Decentralized cognitive radio networks (CRN) require efficient channel access protocols to enable cognitive secondary users (SUs) to access the primary channels in an opportunistic way Without any coordination. In this paper, we develop a distributed spectrum access protocol for the case where the SUs aim to maximize the total system throughput while competing for spectrum resources. To model the...
The periodic sensing requirements in cognitive radios cause interruptions for secondary user (SU) communication. As a result, the throughput of the secondary system during sensing can be very low. In this paper, we propose a monitoring scheme for Orthogonal Frequency Division Multiplexing (OFDM) based cognitive radio which can monitor the spectrum during ongoing communication and detect the emergence...
We suggest a cooperative spectrum sensing scheme for wideband cognitive radio network when primary user emulation attack (PUEA) is present. PUEA is known to be one of the practical challenges in deploying cognitive networks, where some malicious users try to emulate the primary signal and seduce unlicensed users to not let them access the unoccupied frequency. In this paper, the detection of primary...
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