The Experts below are selected from a list of 7098 Experts worldwide ranked by ideXlab platform
Ahmed El Shafie - One of the best experts on this subject based on the ideXlab platform.
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Cooperative Access Schemes for Efficient SWIPT Transmissions in Cognitive Radio Networks
arXiv: Networking and Internet Architecture, 2016Co-Authors: Ahmed El Shafie, Naofal Al-dhahir, Ridha HamilaAbstract:We investigate joint information and energy cooperative schemes in a slotted-time cognitive radio network with a Primary Transmitter-receiver pair and a set of secondary Transmitter-receiver pairs. The Primary Transmitter is assumed to be an energy-harvesting node. We propose a three-stage cooperative transmission protocol. During the first stage, the Primary user releases a portion of its time slot to the secondary nodes to send their data and to power the energy-harvesting Primary Transmitter from the secondary radio-frequency signals. During the second stage, the Primary Transmitter sends its data to its destination and to the secondary nodes. During the third stage, the secondary nodes amplify and forward the Primary data. We propose five different schemes for secondary access and powering the Primary Transmitter. We derive closed-form expressions for the Primary and secondary rates for all the proposed schemes. Two of the proposed schemes use distributed beamforming to power the Primary Transmitter. We design a sparsity-aware relay-selection scheme based on the compressive sensing principles. Our numerical results demonstrate the gains of our proposed schemes for both the Primary and secondary systems.
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Maximum Secondary Stable Throughput of a Cooperative Secondary Transmitter–Receiver Pair: Protocol Design and Stability Analysis
IEEE Transactions on Vehicular Technology, 2016Co-Authors: Ahmed El Shafie, Tamer Khattab, Amr El-keyi, Mohamed NafieAbstract:In this paper, we investigate the impact of cooperation between a secondary Transmitter–receiver pair and a Primary Transmitter on the maximum stable throughput of the Primary–secondary network. Each Transmitter, either Primary or secondary, has a buffer for storing its own traffic. In addition to its own buffer, the secondary Transmitter has a buffer for storing a fraction of the undelivered Primary packets due to channel impairments. Moreover, the secondary destination has a relaying queue (buffer) for storing a fraction of the undelivered Primary packets. In our proposed cooperative system, the secondary Transmitter and the secondary destination increase the spectrum availability for the secondary packets by relaying the unsuccessfully transmitted packets of the Primary Transmitter. We consider two multiple-access strategies to be used by the secondary Transmitter and the secondary destination to utilize the silence sessions of the Primary Transmitter. Numerical results demonstrate the gains of our proposed cooperative system over the noncooperation case and the systems when the secondary Transmitter is the only cooperating node in the network.
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GLOBECOM Workshops - Cooperative Access Schemes for Efficient SWIPT Transmissions in Cognitive Radio Networks
2015 IEEE Globecom Workshops (GC Wkshps), 2015Co-Authors: Ahmed El Shafie, Naofal Al-dhahir, Ridha HamilaAbstract:We investigate joint information and energy cooperative schemes in a slotted-time cognitive radio network with a Primary Transmitter-receiver pair and a set of secondary Transmitter-receiver pairs. The Primary Transmitter is assumed to be an energy-harvesting node. We propose a three-stage cooperative transmission protocol. During the first stage, the Primary user releases a portion of its time slot to the secondary nodes to send their data and to power the energy-harvesting Primary Transmitter from the secondary radio-frequency signals. During the second stage, the Primary Transmitter sends its data to its destination and to the secondary nodes. During the third stage, the secondary nodes amplify and forward the Primary data. We propose five different schemes for secondary access and powering the Primary Transmitter. We derive closed-form expressions for the Primary and secondary rates for all the proposed schemes. Two of the proposed schemes use distributed beamforming to power the Primary Transmitter. We design a sparsity-aware relay-selection scheme based on the compressive sensing principles. Our numerical results demonstrate the gains of our proposed schemes for both the Primary and secondary systems.
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CrownCom - Transmit and receive cooperative cognition: Protocol design and stability analysis
8th International Conference on Cognitive Radio Oriented Wireless Networks, 2013Co-Authors: Ahmed El Shafie, Tamer Khattab, Amr El-keyi, Mohamed NafieAbstract:In this paper, we investigate the stability of a cooperative cognitive system. We propose a cooperative secondary Transmitter-receiver system (CSTR), where, the secondary Transmitter (ST) and the secondary receiver (SR) increase the spectrum availability for the ST packets by relaying the unsuccessfully transmitted packets of the Primary Transmitter (PT). We assume receiving nodes with multipacket reception capability (MPR). We provide two inner bounds and two outer bounds on the stability region of the considered system.
Vijayarangan - One of the best experts on this subject based on the ideXlab platform.
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Comparison of Primary Transmitter Detection based Spectrum Sensing Techniques in Cognitive Radio Systems
Wireless Communication, 2012Co-Authors: P. Lingeswari, K.j. Prasanna Venkatesan, VijayaranganAbstract:Cognitive Radios aim to implement dynamic frequency usage which is proposed to increase the efficiency of the spectrum and can sense their environment, detect the idle bands and then allocate the secondary users into the detected idle bands without any interference to Primary users‟ communications. There are three main techniques for spectrum sensing: Primary Transmitter detection, cooperative detection and interference based detection. This paper focuses on sensing the idle bands using Transmitter detection techniques in Cognitive Radio based systems. Generally Transmitter detection includes three techniques: energy detection, matched filter detection and cyclostationary feature detection. Using simulations, a comparative analysis of the three techniques has been carried out in terms of power spectral density for low signal to noise ratio. It has been found that energy detection out performs the other techniques by means of detection probability and also the sensing time is less as compared to cyclostationary feature detection. Hence, Energy detection does not require the prior knowledge about the Primary signal. The simulation results are analyzed.
Harpreet S. Dhillon - One of the best experts on this subject based on the ideXlab platform.
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Coexistence of RF-powered IoT and a Primary Wireless Network With Secrecy Guard Zones
IEEE Transactions on Wireless Communications, 2018Co-Authors: Mustafa A. Kishk, Harpreet S. DhillonAbstract:This paper studies the secrecy performance of a wireless network (Primary network) overlaid with an ambient RF energy harvesting Internet of Things (IoT) network (secondary network). The nodes in the secondary network are assumed to be solely powered by ambient RF energy harvested from the transmissions of the Primary network. We assume that the secondary nodes can eavesdrop on the Primary transmissions due to which the Primary network uses secrecy guard zones . The Primary Transmitter goes silent if any secondary receiver is detected within its guard zone. Using tools from stochastic geometry, we derive the probability of successful connection of the Primary network as well as the probability of secure communication. Two conditions must be jointly satisfied in order to ensure successful connection: 1) the signal-to-interference-plus-noise ratio (SINR) at the Primary receiver is above a predefined threshold, and 2) the Primary Transmitter is not silent. In order to ensure secure communication, the SINR value at each of the secondary nodes should be less than a predefined threshold. Clearly, when more secondary nodes are deployed, more Primary Transmitters will remain silent for a given guard zone radius, which will in turn impact the amount of energy harvested by the secondary network. Our results concretely show the existence of an optimal deployment density for the secondary network that maximizes the density of nodes that are able to harvest sufficient amount of energy. Furthermore, we show the dependence of this optimal deployment density on the guard zone radius of the Primary network. In addition, we show that the optimal guard zone radius selected by the Primary network is a function of the deployment density of the secondary network. This interesting coupling between the performance of the two networks is studied using tools from game theory. We propose an algorithm that can assist the two networks to converge to Nash equilibrium. The convergence of this algorithm is verified using simulations. Overall, this paper is one of the few concrete works that symbiotically merge tools from stochastic geometry and game theory.
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Coexistence of RF-powered IoT and a Primary Wireless Network with Secrecy Guard Zones
arXiv: Information Theory, 2017Co-Authors: Mustafa A. Kishk, Harpreet S. DhillonAbstract:This paper studies the secrecy performance of a wireless network (Primary network) overlaid with an ambient RF energy harvesting IoT network (secondary network). The nodes in the secondary network are assumed to be solely powered by ambient RF energy harvested from the transmissions of the Primary network. We assume that the secondary nodes can eavesdrop on the Primary transmissions due to which the Primary network uses secrecy guard zones. The Primary Transmitter goes silent if any secondary receiver is detected within its guard zone. Using tools from stochastic geometry, we derive the probability of successful connection of the Primary network as well as the probability of secure communication. Two conditions must be jointly satisfied in order to ensure successful connection: (i) the SINR at the Primary receiver is above a predefined threshold, and (ii) the Primary Transmitter is not silent. In order to ensure secure communication, the SINR value at each of the secondary nodes should be less than a predefined threshold. Clearly, when more secondary nodes are deployed, more Primary Transmitters will remain silent for a given guard zone radius, thus impacting the amount of energy harvested by the secondary network. Our results concretely show the existence of an optimal deployment density for the secondary network that maximizes the density of nodes that are able to harvest sufficient amount of energy. Furthermore, we show the dependence of this optimal deployment density on the guard zone radius of the Primary network. In addition, we show that the optimal guard zone radius selected by the Primary network is a function of the deployment density of the secondary network. This interesting coupling between the two networks is studied using tools from game theory. Overall, this work is one of the few concrete works that symbiotically merge tools from stochastic geometry and game theory.
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WCNC - Modeling and Analysis of Ambient RF Energy Harvesting in Networks with Secrecy Guard Zones
2017 IEEE Wireless Communications and Networking Conference (WCNC), 2017Co-Authors: Mustafa A. Kishk, Harpreet S. DhillonAbstract:This paper studies the secrecy performance in wireless networks (Primary network) overlaid with an ambient RF energy harvesting network (secondary network). The nodes in the secondary network are assumed to be solely powered by ambient RF energy harvested from transmissions of the Primary network. We assume that the secondary nodes can eavesdrop on the Primary transmissions due to which the Primary network uses {\em secrecy guard zones}. The Primary Transmitter goes silent if any secondary receiver is detected within its guard zone. Using tools from stochastic geometry, we first derive the optimal guard zone radius that minimizes the probability of going silent while ensuring a predefined minimum secure connection probability. Clearly, when more secondary nodes are deployed, more Primary Transmitters will remain silent for a given guard zone radius, thus impacting the amount of energy harvested by the secondary network. This introduces an interesting coupling between the performance of the two networks. We study this coupling using tools from game theory and propose an algorithm that can assist the two networks to converge to Nash equilibrium. Our results demonstrate the convergence of the proposed algorithm to the Nash equilibrium in finite number of iterations. Overall, this work forms one of the few concrete works that symbiotically merge tools from stochastic geometry and game theory.
Khalid A. Qaraqe - One of the best experts on this subject based on the ideXlab platform.
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GLOBECOM Workshops - Secrecy Outage Performance for Underlay MIMO CRNs with Energy Harvesting and Transmit Antenna Selection
2016 IEEE Globecom Workshops (GC Wkshps), 2016Co-Authors: Hongjiang Lei, Huan Zhang, Gaofeng Pan, Imran Shafique Ansari, Khalid A. QaraqeAbstract:This paper considers underlay multiple-input multiple-output cognitive radio networks including a Primary Transmitter, a Primary receiver, a secondary source, a secondary destination, and an eavesdropper, where the secondary Transmitter is powered by renewable energy that is harvested from the Primary Transmitter in order to improve both energy efficiency and spectral efficiency. It is assumed that all the channel state information are available and transmit antenna selection scheme is utilized at the secondary Transmitter. We investigate the secrecy outage performance of the secondary system and the closed-form expression for the secrecy outage probability is derived. Simulations are conducted to validate the accuracy of our derived analytical results. Results show that the secrecy performance of the secondary system improves as the transmit antenna number and the receiver antenna number increases.
P. Lingeswari - One of the best experts on this subject based on the ideXlab platform.
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Comparison of Primary Transmitter Detection based Spectrum Sensing Techniques in Cognitive Radio Systems
Wireless Communication, 2012Co-Authors: P. Lingeswari, K.j. Prasanna Venkatesan, VijayaranganAbstract:Cognitive Radios aim to implement dynamic frequency usage which is proposed to increase the efficiency of the spectrum and can sense their environment, detect the idle bands and then allocate the secondary users into the detected idle bands without any interference to Primary users‟ communications. There are three main techniques for spectrum sensing: Primary Transmitter detection, cooperative detection and interference based detection. This paper focuses on sensing the idle bands using Transmitter detection techniques in Cognitive Radio based systems. Generally Transmitter detection includes three techniques: energy detection, matched filter detection and cyclostationary feature detection. Using simulations, a comparative analysis of the three techniques has been carried out in terms of power spectral density for low signal to noise ratio. It has been found that energy detection out performs the other techniques by means of detection probability and also the sensing time is less as compared to cyclostationary feature detection. Hence, Energy detection does not require the prior knowledge about the Primary signal. The simulation results are analyzed.