References of "Leus, Geert"
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See detailTo AND or To OR: On Energy-Efficient Distributed Spectrum Sensing with Combined Censoring and Sleeping
Maleki, Sina UL; Leus, Geert; Chatzinotas, Symeon UL et al

in IEEE Transactions on Wireless Communications (2015)

Distributed spectrum sensing improves the detection reliability of a cognitive radio network but generally comes at the price of a large power consumption. Since cognitive radios are generally low-power ... [more ▼]

Distributed spectrum sensing improves the detection reliability of a cognitive radio network but generally comes at the price of a large power consumption. Since cognitive radios are generally low-power sensors with limited batteries, a combined censoring and sleeping scheme is considered as an energy-efficient algorithm for distributed spectrum sensing. Each sensor switches off its sensing module with a specific sleeping rate. When the sensor is on, a censoring policy is employed in order to send the sensing result to the fusion center. The result is only transmitted, if it is deemed to be informative. Hence, the energy consumption of each sensor, including the sensing and transmission energies, is reduced. The underlying sensing parameters are derived by minimizing the maximum average energy consumption per sensor subject to a lower-bound on the global probability of detection and an upper-bound on the global probability of false alarm. We analyze the problem for the OR and the AND rule and provide a performance analysis for a case study based on the IEEE 802.15.4/ZigBee standard. It is shown that the combined censoring and sleeping scheme achieves a significant energy saving compared to the case where no censoring or sleeping is taken into account. [less ▲]

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See detailTo AND or To OR: How Shall the Fusion Center Rule in Energy-Constrained Cognitive Radio Networks?
Maleki, Sina UL; Leus, Geert; Chatzinotas, Symeon UL et al

in IEEE International Conference on Communications (ICC), 10-14 June 2014, Sydney, Australia (2014, June)

Distributed spectrum sensing enhances the detection reliability of a cognitive radio network. However, this comes at the price of a higher energy consumption. To solve this problem, a combined censoring ... [more ▼]

Distributed spectrum sensing enhances the detection reliability of a cognitive radio network. However, this comes at the price of a higher energy consumption. To solve this problem, a combined censoring and sleeping scheme is considered where the cognitive radios switch off their sensing module with a specific sleeping rate in each sensing period. The awake cognitive radios send their local decisions to the fusion center only if it is deemed to be informative. The fusion center either employs the OR or the AND rule to make the final decision about the presence or absence of the primary user. This paper investigates which rule performs better in terms of energy efficiency under various conditions. The underlying sensing parameters are derived by minimizing the maximum average energy consumption per sensor subject to a constraint on the probabilities of false alarm and detection. This way, it can be ensured that the spectrum opportunities are utilized efficiently while the primary users are not interfered with. A case study based on IEEE 802.15.4/ZigBee is considered for performance evaluation. It is shown that significant energy savings can be obtained by employing combined censoring and sleeping. [less ▲]

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See detailDistributed Wideband Spectrum Sensing for Cognitive Radio Networks
Arroyo-Valles, Rocio; Maleki, Sina UL; Leus, Geert

in 2014 IEEE International Conference on Acoustics Speech and Signal Processing (ICASSP) (2014, May)

Wideband spectrum sensing improves the agility of spectrum sensing and spectrum hand-off in cognitive radio systems. In this paper, a distributed wideband spectrum sensing technique over adaptive ... [more ▼]

Wideband spectrum sensing improves the agility of spectrum sensing and spectrum hand-off in cognitive radio systems. In this paper, a distributed wideband spectrum sensing technique over adaptive diffusion networks is proposed. Considering unknown and different channels between the primary and the cognitive users, an averaged received power spectrum across all the cognitive users is estimated by each user using diffusion adaptation techniques. This averaged power spectrum estimate is reliable enough for the users to perform spectrum sensing and make a decision regarding the presence or the absence of the primary user. The simulation results show that the detection performance of the system improves with the number of iterations. Further, a satisfactory detection performance at low SNRs is achieved after a few iterations, which is a desired characteristic for cognitive radio systems. Finally, it is shown that the cooperative technique outperforms the non-cooperative one in terms of estimation accuracy and detection performance. [less ▲]

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See detailOptimization of hard fusion based spectrum sensing for energy-constrained cognitive radio networks
Maleki, Sina UL; Prabhakar Chepuri, Sundeep; Leus, Geert

in Physical Communication (2013), 9

The detection reliability of a cognitive radio network improves by employing a cooperative spectrum sensing scheme. However, increasing the number of cognitive radios entails a growth in the cooperation ... [more ▼]

The detection reliability of a cognitive radio network improves by employing a cooperative spectrum sensing scheme. However, increasing the number of cognitive radios entails a growth in the cooperation overhead of the system. Such an overhead leads to a throughput degradation of the cognitive radio network. Since current cognitive radio networks consist of low-power radios, the energy consumption is another critical issue. In this paper, throughput optimization of the hard fusion based sensing using the k-out-of-N rule is considered. We maximize the throughput of the cognitive radio network subject to a constraint on the probability of detection and energy consumption per cognitive radio in order to derive the optimal number of users, the optimal k and the best probability of false alarm. The simulation results based on the IEEE 802.15.4/ZigBee standard, show that the majority rule is either optimal or almost optimal in terms of the network throughput. [less ▲]

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See detailA censoring strategy for decentralized estimation in energy-constrained adaptive diffusion networks
Arroyo-Valles, Rocio; Maleki, Sina UL; Leus, Geert

in IEEE 14th Workshop on Signal Processing Advances in Wireless Communications (SPAWC), 2013 (2013, June)

This paper presents a censoring strategy for distributed estimation over adaptive networks in scenarios where energy resources are limited. Sensors apply selective communication policies in order to save ... [more ▼]

This paper presents a censoring strategy for distributed estimation over adaptive networks in scenarios where energy resources are limited. Sensors apply selective communication policies in order to save energy for being able to transmit more important information later. Simulation results show an enhancement in network lifetime, by reducing communication processes among nodes with a slightly degraded result, compared with energy unconstrained schemes. [less ▲]

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See detailCensored Truncated Sequential Spectrum Sensing for Cognitive Radio Networks
Maleki, Sina UL; Leus, Geert

in IEEE Journal on Selected Areas In Communications (2013), 31(3), 364-378

Reliable spectrum sensing is a key functionality of a cognitive radio network. Cooperative spectrum sensing improves the detection reliability of a cognitive radio system but also increases the system ... [more ▼]

Reliable spectrum sensing is a key functionality of a cognitive radio network. Cooperative spectrum sensing improves the detection reliability of a cognitive radio system but also increases the system energy consumption which is a critical factor particularly for low-power wireless technologies. A censored truncated sequential spectrum sensing technique is considered as an energy-saving approach. To design the underlying sensing parameters, the maximum average energy consumption per sensor is minimized subject to a lower bounded global probability of detection and an upper bounded false alarm rate. This way both the interference to the primary user due to miss detection and the network throughput as a result of a low false alarm rate are controlled. To solve this problem, it is assumed that the cognitive radios and fusion center are aware of their location and mutual channel properties. We compare the performance of the proposed scheme with a fixed sample size censoring scheme under different scenarios and show that for low-power cognitive radios, censored truncated sequential sensing outperforms censoring. It is shown that as the sensing energy per sample of the cognitive radios increases, the energy efficiency of the censored truncated sequential approach grows significantly. [less ▲]

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See detailCensored truncated sequential spectrum sensing for cognitive radio networks
Maleki, Sina UL; Leus, Geert

in 17th International Conference on Digital Signal Processing (DSP), 2011 (2011, July)

A truncated censored sequential spectrum sensing technique is considered as an energy saving approach for a cooperative spectrum sensing system. In order to design the underlying sensing parameters, the ... [more ▼]

A truncated censored sequential spectrum sensing technique is considered as an energy saving approach for a cooperative spectrum sensing system. In order to design the underlying sensing parameters, the maximum energy consumption per sensor is minimized subject to a lower bounded global probability of detection and an upper bounded false alarm rate. We compare the performance of the proposed scheme with a fixed sample size censoring scheme. It is shown that the truncated censored sensing approach is highly energy efficient, particularly when the sensing cost is high. [less ▲]

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See detailEnergy and throughput efficient strategies for cooperative spectrum sensing in cognitive radios
Maleki, Sina UL; Prabhakar Chepuri, Sundeep; Leus, Geert

in 2011 IEEE 12th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC) (2011, June)

An efficient cooperative spectrum sensing based cognitive radio network employs a certain number of secondary users to sense the spectrum while satisfying a constraint on the detection performance. We ... [more ▼]

An efficient cooperative spectrum sensing based cognitive radio network employs a certain number of secondary users to sense the spectrum while satisfying a constraint on the detection performance. We derive the optimal number of cognitive radios under two scenarios: an energy efficient and a throughput optimization setup. In the energy efficient setup, the number of cooperating cognitive radios is minimized for a k-out-of-N fusion rule with a constraint on the probability of detection and false alarm while in the throughput optimization setup, we maximize the throughput of the cognitive radio network, by deriving the optimal reporting time in a sensing time frame which is proportional to the number of cognitive users, subject to a constraint on the probability of detection. It is shown that both problems can be simplified to line search problems. The simulation results show that the OR and the majority rule outperform the AND rule in terms of energy efficiency and that the OR rule gives a higher throughput than the AND rule with a smaller number of users. [less ▲]

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See detailEnergy-Efficient Distributed Spectrum Sensing for Cognitive Sensor Networks
Maleki, Sina UL; Pandharipande, Ashish; Leus, Geert

in IEEE Sensors Journal (2011), 11(3), 565-573

Reliability and energy consumption in detection are key objectives for distributed spectrum sensing in cognitive sensor networks. In conventional distributed sensing approaches, although the detection ... [more ▼]

Reliability and energy consumption in detection are key objectives for distributed spectrum sensing in cognitive sensor networks. In conventional distributed sensing approaches, although the detection performance improves with the number of radios, so does the network energy consumption. We consider a combined sleeping and censoring scheme as an energy efficient spectrum sensing technique for cognitive sensor networks. Our objective is to minimize the energy consumed in distributed sensing subject to constraints on the detection performance, by optimally choosing the sleeping and censoring design parameters. The constraint on the detection performance is given by a minimum target probability of detection and a maximum permissible probability of false alarm. Depending on the availability of prior knowledge about the probability of primary user presence, two cases are considered. The case where a priori knowledge is not available defines the blind setup; otherwise the setup is called knowledge-aided. By considering a sensor network based on IEEE 802.15.4/ZigBee radios, we show that significant energy savings can be achieved by the proposed scheme. [less ▲]

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See detailOptimal hard fusion strategies for cognitive radio networks
Maleki, Sina UL; Prabhakar Chepuri, Sundeep; Leus, Geert

in IEEE Wireless Communications and Networking Conference (WCNC), 2011 (2011, March)

Optimization of hard fusion spectrum sensing using the k-out-of-N rule is considered. Two different setups are used to derive the optimal k. A throughput optimization setup is defined by minimizing the ... [more ▼]

Optimization of hard fusion spectrum sensing using the k-out-of-N rule is considered. Two different setups are used to derive the optimal k. A throughput optimization setup is defined by minimizing the probability of false alarm subject to a probability of detection constraint representing the interference of a cognitive radio with the primary user, and an interference management setup is considered by maximizing the probability of detection subject to a false alarm rate constraint. It is shown that the underlying problems can be simplified to equality constrained optimization problems and an algorithm to solve them is presented. We show the throughput optimization and interference management setups are dual. The simulation results show the majority rule is optimal or near optimal for the desirable range of false alarm and detection rates for a cognitive radio network. Furthermore, an energy efficient setup is considered where the number of cognitive radios is to be minimized for the AND and the OR rule and a certain probability of detection and false alarm constraint. The simulation results show that the OR rule outperforms the AND rule in terms of energy efficiency. [less ▲]

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See detailTwo-stage spectrum sensing for cognitive radios
Maleki, Sina UL; Pandharipande, Ashish; Leus, Geert

in 2010 IEEE International Conference on Acoustics Speech and Signal Processing (ICASSP) (2010, March)

We consider a two-stage sensing scheme for cognitive radios where coarse sensing based on energy detection is performed in the first stage and, if required, fine sensing based on cyclostationary detection ... [more ▼]

We consider a two-stage sensing scheme for cognitive radios where coarse sensing based on energy detection is performed in the first stage and, if required, fine sensing based on cyclostationary detection in the second stage. We design the detection threshold parameters in the two sensing stages so as to maximize the probability of detection, given constraints on the probability of false alarm. We compare this scheme with ones where only energy detection or cyclostationary detection is performed. The performance comparison is made based on the probability of detection, probability of false alarm and mean detection time. [less ▲]

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See detailEnergy-efficient distributed spectrum sensing with convex optimization
Maleki, Sina UL; Pandharipande, Ashish; Leus, Geert

in 3rd IEEE International Workshop on Computational Advances in Multi-Sensor Adaptive Processing (CAMSAP), 2009 (2009, December)

We consider the problem of distributed spectrum sensing in cognitive radio networks with a central fusion center, from an energy efficiency viewpoint. In our scheme, each cognitive radio adopts a ... [more ▼]

We consider the problem of distributed spectrum sensing in cognitive radio networks with a central fusion center, from an energy efficiency viewpoint. In our scheme, each cognitive radio adopts a combination of sleeping and censoring to obtain a sensing result based on energy detection, while the fusion center combines all the sensing results using an OR decision rule. Our goal is to minimize the network energy consumption, given constraints on the global probabilities of detection and false-alarm. We show that the underlying optimization problem can be solved as a convex optimization problem. We then show the energy efficiency of our scheme via simulations using a ZigBee transceiver model. [less ▲]

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See detailEnergy-efficient spectrum sensing for cognitive sensor networks
Maleki, Sina UL; Pandharipande, Ashish; Leus, Geert

in 35th Annual Conference of IEEE Industrial Electronics, 2009. IECON '09 (2009, November)

We consider a combined sleeping and censoring scheme for energy-efficient spectrum sensing in cognitive sensor networks. We analyze the detection performance of this scheme by theoretically deriving the ... [more ▼]

We consider a combined sleeping and censoring scheme for energy-efficient spectrum sensing in cognitive sensor networks. We analyze the detection performance of this scheme by theoretically deriving the global probabilities of detection and false-alarm. Our goal is to minimize the energy consumption incurred in distributed sensing, given constraints on the global probabilities of detection and false-alarm, by optimally designing the sleeping rate and the censoring thresholds. Using specific transceiver models for sensors based on IEEE 802.15.4/ZigBee, we show the energy savings achieved under an optimum choice of the design parameters. [less ▲]

Detailed reference viewed: 72 (3 UL)