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Mohamed Nafie - One of the best experts on this subject based on the ideXlab platform.
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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 Elkeyi, 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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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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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.
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Maximum Secondary Stable Throughput of a Cooperative Secondary Transmitter-Receiver Pair: Protocol Design and Stability Analysis
arXiv: Information Theory, 2012Co-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 (PT) on the maximum stable throughput of the primary-Secondary network. Each Transmitter, primary or Secondary, has a buffer for storing its own traffic. In addition to its own buffer, the Secondary Transmitter (ST) has a buffer for storing a fraction of the undelivered primary packets due to channel impairments. Moreover, the Secondary destination has a relaying queue for storing a fraction of the undelivered primary packets. In the proposed cooperative system, the ST and the Secondary destination increase the spectrum availability for the Secondary packets by relaying the unsuccessfully transmitted packets of the PT. We consider two multiple access strategies to be used by the ST and the Secondary destination to utilize the silence sessions of the PT. Numerical results demonstrate the gains of the proposed cooperative system over the non-cooperation case.
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ICT - An achievable rate region for a primary network shared by a Secondary link
2010 17th International Conference on Telecommunications, 2010Co-Authors: John Tadrous, Ahmed Sultan, Mohamed NafieAbstract:We consider a multiple access primary network with N Transmitters. A Secondary link of one Transmitter and a corresponding receiver causes interference to the primary network. An achievable rate region for the primary network and the Secondary link is obtained given the following mode of operation. The Secondary Transmitter employs rate-splitting so that the primary receiver can decode part of the Secondary's signal and cancel it. The Secondary receiver, on the other hand, treats primary interference as noise. Given a Gaussian channel model, we investigate the effect of rate-splitting on the rate region for two cases. The first case is when the link between the Secondary Transmitter and the primary receiver supports a higher data rate than that of the link between the Secondary Transmitter and its corresponding receiver. The second case is the opposite scenario. For each case we determine the optimal rate-splitting that maximizes the sum throughput of the primary network and the Secondary link subject to a constraint on primary rate. The optimal solution for the first case does not require rate-splitting. For the second, rate-splitting is needed and the primary rate constraint is met with equality.
Fazlul Kader - One of the best experts on this subject based on the ideXlab platform.
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A power-domain NOMA based overlay spectrum sharing scheme
Future Generation Computer Systems, 2020Co-Authors: Fazlul KaderAbstract:Abstract Non-orthogonal multiple access (NOMA) and cooperative spectrum sharing (CSS) are integrated into this work to enhance both spectrum efficiency and utilization. A clustering-based overlay spectrum sharing is proposed by exploiting NOMA in coordinated direct and relay transmission (CDRT) (termed as CSS-NOMA-CDRT). In CSS-NOMA-CDRT, a primary strong NOMA user is directly served by the primary Transmitter, whereas a primary NOMA weak user needs the assistance of a relay to communicate with the primary Transmitter within a cluster. Instead of using a dedicated relay, a Secondary Transmitter acts as a relay to forward the primary symbol to NOMA weak user and the Secondary Transmitter transmits own symbol to its receiver at the same time. The performance of the proposed CSS-NOMA-CDRT is evaluated with closed-form solutions, in terms of ergodic sum capacity and outage probability. Through the analytical and Monte Carlo simulation results, it is demonstrated that CSS-NOMA-CDRT can obtain remarkable capacity gain as compared to the conventional NOMA-based CDRT.
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ICUFN - Cooperative spectrum sharing with space time block coding and non-orthogonal multiple access
2016 Eighth International Conference on Ubiquitous and Future Networks (ICUFN), 2016Co-Authors: Fazlul Kader, Soo Young ShinAbstract:In this paper, we have proposed a novel two-phase cooperative spectrum sharing protocol on the basis of Alamouti space time block coded (STBC) non-orthogonal multiple access. The network scenario comprising of a primary Transmitter-receiver pair and a Secondary Transmitter-receiver pair. During the first two time slots, the primary Transmitter transmits two STBC primary symbols to the cooperative Secondary Transmitter. The Secondary Transmitter acting as a decode-and-forward relay for the primary system is allowed to transmit its own Secondary signal superposed on the STBC coded primary signal in exchange of cooperation during the next two time slots. Simulation and theoretical results demonstrate the efficacy of the proposed protocol compared to the conventional super positing coding based overlay scheme in terms of the outage probability and the ergodic capacity.
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Outage capacity analysis of a Secondary network in interference limited cognitive radio spectrum sharing system
2014 17th International Conference on Computer and Information Technology (ICCIT), 2014Co-Authors: Fazlul Kader, Asaduzzaman, Soo Young ShinAbstract:In this paper, we investigate the outage capacity of a Secondary network in a cognitive radio (CR) cooperative spectrum sharing system consisting of a primary Transmitter (PTx)-receiver (PRx) pair as well as multiple Secondary Transmitter (STx)-receiver (SRx) pairs. We evaluate the outage capacity of the Secondary network in slow fading channel by considering three different scenarios based on the primary user (PU) activity. The scenarios are: spectrum access by a Secondary user (SU) when the data rate of the PTx to PRx over the direct link achieves primary request target rate R PT , spectrum access by a SU when the data rate of the PTx to PRx falls below R PT over the direct link but achieves R PT on the relaying link (PTx-relay-PRx) and spectrum access by two SUs at the same time when PTx-PRx pair is idle or primary system is in outage. In this paper, a closed-form expression of the outage capacity is derived. Theoretical results show that outage capacity improves when the active Secondary Transmitter is located farther away from the PRx.
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Hybrid Spectrum Sharing with Cooperative Secondary User Selection in Cognitive Radio Networks
KSII Transactions on Internet and Information Systems, 2013Co-Authors: Fazlul Kader, Asaduzzaman, Moshiul HoqueAbstract:In this paper, we propose a cooperative hybrid spectrum sharing protocol by jointly considering interweave (opportunistic) and underlay schemes. In the proposed protocol, Secondary users can access the licensed spectrum along with the primary system. Our network scenario comprises a single primary Transmitter-receiver (PTx-PRx) pair and a group of M Secondary Transmitter-receiver (STx-SRx) pairs within the transmission range of the primary system. Secondary Transmitters are divided into two groups: active and inactive. A Secondary Transmitter that gets an opportunity to access the Secondary spectrum is called “active”. One of the idle or inactive Secondary Transmitters that achieves the primary request target rate R PT will be selected as a best decode-and-forward (DF) relay (Re) to forward the primary information when the data rate of the direct link between PTx and PRx falls below R PT . We investigate the ergodic capacity and outage probability of the primary system with cooperative relaying and outage probability of the Secondary system. Our theoretical and simulation results show that both the primary and Secondary systems are able to achieve performance improvement in terms of outage probability. It is also shown that ergodic capacity and outage probability improve when the active Secondary Transmitter is located farther away from the PRx.
Daesik Hong - One of the best experts on this subject based on the ideXlab platform.
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optimal spectrum access for energy harvesting cognitive radio networks
IEEE Transactions on Wireless Communications, 2013Co-Authors: Sungsoo Park, Daesik HongAbstract:We consider energy harvesting cognitive radio networks in which a Secondary Transmitter harvests energy from ambient sources or wireless power transfer systems while opportunistically accessing the spectrum licensed to the primary network. The primary traffic is modeled as a time-homogeneous discrete Markov process, and the Secondary Transmitter may not be able to operate continuously due to sporadic and unstable energy sources. At the beginning of each time slot, the Secondary Transmitter thus needs to determine whether to remain idle so as to conserve energy, or to execute spectrum sensing to acquire knowledge of the current spectrum occupancy state. It also needs to configure the spectrum sensor detection threshold to achieve an effective tradeoff between false alarms and misdetections. This sequential decision-making, done to maximize the expected total throughput, requires the joint design of a spectrum sensing policy and a detection threshold under the energy causality and collision constraints. We formulate this stochastic optimization problem as a constrained partially observable Markov decision process (POMDP), and then convert it to a computationally tractable unconstrained POMDP. Numerical results show that the proposed approach enables efficient usage of the harvested energy by exploiting the temporal correlation of the primary traffic.
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Outage Probability of Cognitive Relay Networks with Interference Constraints
IEEE Transactions on Wireless Communications, 2011Co-Authors: Jemin Lee, Hano Wang, Jeffrey G. Andrews, Daesik HongAbstract:This paper evaluates the outage probability of cognitive relay networks with cooperation between Secondary users based on the underlay approach, while adhering to the interference constraint on the primary user, i.e., the limited amount of interference which the primary user can tolerate. A relay selection criterion, suitable for cognitive relay networks, is provided, and using it, we derive the outage probability. It is shown that the outage probability of cognitive relay networks is higher than that of conventional relay networks due to the interference constraint, and we quantify the increase. In addition, the outage probability is affected by the distance ratio of the interference link (between the Secondary Transmitter and the primary receiver) to the relaying link (between the Secondary Transmitter and the Secondary receiver). We also prove that cognitive relay networks achieve the same full selection diversity order as conventional relay networks, and that the decrease in outage probability achieved by increasing the selection diversity (the number of relays) is not less than that in conventional relay networks.
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capacity enhancement of Secondary links through spatial diversity in spectrum sharing
IEEE Transactions on Wireless Communications, 2010Co-Authors: Hano Wang, Jemin Lee, Sungtae Kim, Daesik HongAbstract:Previous investigations on capacity of Secondary users in spectrum-sharing environments have determined the capacity of a Secondary link based on the interference power threshold set at the primary receiver. In contrast to these previous works, we show that the capacity of a Secondary link is determined based on a geographical relationship expressed as the ratio of the distance between the primary receiver and Secondary Transmitter to the distance between the Secondary Transmitter and receiver. Proceeding from that and in an effort, to enhance the capacity of the Secondary user, which is limited by this distance-ratio, we adopt a Secondary Transmitter with M antennas. Furthermore, we analyze the capacity achieved using a simple antenna selection process.
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Throughput maximization of SINR-based spectrum sharing policy
TENCON 2009 - 2009 IEEE Region 10 Conference, 2009Co-Authors: Hano Wang, Dongkyu Kim, Gosan Noh, Daesik HongAbstract:We propose a spectrum sharing policy based on signal-to-interference-noise ratio (SINR) at a primary receiver. Contrast to the conventional spectrum sharing policy based on full channel state information (CSI) feedback, in our spectrum sharing policy, a Secondary link can share the primary user's spectrum only using a binary state feedback for the interference link between a Secondary Transmitter and a primary receiver. In this paper, the maximized throughput of the proposed spectrum sharing policy is analyzed. The maximized throughput is determined by the ratio of the distance between the Secondary Transmitter and the primary receiver to the distance between the Secondary Transmitter and receiver. A Secondary link with large distance ratio value can support high data rate applications only using simple binary state feedback as long as the SINR constraint of the primary user is guaranteed.
Ahmed El Shafie - One of the best experts on this subject based on the ideXlab platform.
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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 Elkeyi, 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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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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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.
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Maximum Secondary Stable Throughput of a Cooperative Secondary Transmitter-Receiver Pair: Protocol Design and Stability Analysis
arXiv: Information Theory, 2012Co-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 (PT) on the maximum stable throughput of the primary-Secondary network. Each Transmitter, primary or Secondary, has a buffer for storing its own traffic. In addition to its own buffer, the Secondary Transmitter (ST) has a buffer for storing a fraction of the undelivered primary packets due to channel impairments. Moreover, the Secondary destination has a relaying queue for storing a fraction of the undelivered primary packets. In the proposed cooperative system, the ST and the Secondary destination increase the spectrum availability for the Secondary packets by relaying the unsuccessfully transmitted packets of the PT. We consider two multiple access strategies to be used by the ST and the Secondary destination to utilize the silence sessions of the PT. Numerical results demonstrate the gains of the proposed cooperative system over the non-cooperation case.
Tamer Khattab - One of the best experts on this subject based on the ideXlab platform.
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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 Elkeyi, 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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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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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.
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Maximum Secondary Stable Throughput of a Cooperative Secondary Transmitter-Receiver Pair: Protocol Design and Stability Analysis
arXiv: Information Theory, 2012Co-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 (PT) on the maximum stable throughput of the primary-Secondary network. Each Transmitter, primary or Secondary, has a buffer for storing its own traffic. In addition to its own buffer, the Secondary Transmitter (ST) has a buffer for storing a fraction of the undelivered primary packets due to channel impairments. Moreover, the Secondary destination has a relaying queue for storing a fraction of the undelivered primary packets. In the proposed cooperative system, the ST and the Secondary destination increase the spectrum availability for the Secondary packets by relaying the unsuccessfully transmitted packets of the PT. We consider two multiple access strategies to be used by the ST and the Secondary destination to utilize the silence sessions of the PT. Numerical results demonstrate the gains of the proposed cooperative system over the non-cooperation case.