Aiming at the suppression of enemy air defense(SEAD)task under the complex and complicated combat sce-nario,the spatiotemporal cooperative path planning methods are studied in this paper.The major research contents in...Aiming at the suppression of enemy air defense(SEAD)task under the complex and complicated combat sce-nario,the spatiotemporal cooperative path planning methods are studied in this paper.The major research contents include opti-mal path points generation,path smoothing and cooperative rendezvous.In the path points generation part,the path points availability testing algorithm and the path segments availability testing algorithm are designed,on this foundation,the swarm intelligence-based path point generation algorithm is utilized to generate the optimal path.In the path smoothing part,taking ter-minal attack angle constraint and maneuverability constraint into consideration,the Dubins curve is introduced to smooth the path segments.In cooperative rendezvous part,we take esti-mated time of arrival requirement constraint and flight speed range constraint into consideration,the speed control strategy and flight path control strategy are introduced,further,the decoupling scheme of the circling maneuver and detouring maneuver is designed,in this case,the maneuver ways,maneu-ver point,maneuver times,maneuver path and flight speed are determined.Finally,the simulation experiments are conducted and the acquired results reveal that the time-space cooperation of multiple unmanned aeriel vehicles(UAVs)is effectively real-ized,in this way,the combat situation suppression against the enemy can be realized in SEAD scenarios.展开更多
In order to save energy and make more efficient use of wireless channel, this article puts forward an energy saving cooperative relaying scheme which actuates the cooperative transmission only when the feedback from t...In order to save energy and make more efficient use of wireless channel, this article puts forward an energy saving cooperative relaying scheme which actuates the cooperative transmission only when the feedback from the destination indicates failure of the direct transmission. The proposed scheme selects the optimal relay and its corresponding transmission power in each time slot based on channel condition and residual energy with the objective of minimizing energy consumption and extending network lifetime. In the study, the finite-state Markov channel model is used to characterize the correlation structure of channel fading in wireless networks, and the procedure of relay selection and transmission power decision is formulated as a Markov decision process. Numerical and simulation results show that the proposed scheme consumes less energy and prolongs the network lifetime.展开更多
Cooperative spectrum sensing in cognitive radio is investigated to improve the detection performance of Primary User(PU).Meanwhile,cluster-based hierarchical cooperation is introduced for reducing the overhead as well...Cooperative spectrum sensing in cognitive radio is investigated to improve the detection performance of Primary User(PU).Meanwhile,cluster-based hierarchical cooperation is introduced for reducing the overhead as well as maintaining a certain level of sensing performance.However,in existing hierarchically cooperative spectrum sensing algorithms,the robustness problem of the system is seldom considered.In this paper,we propose a reputation-based hierarchically cooperative spectrum sensing scheme in Cognitive Radio Networks(CRNs).Before spectrum sensing,clusters are grouped based on the location correlation coefficients of Secondary Users(SUs).In the proposed scheme,there are two levels of cooperation,the first one is perfonned within a cluster and the second one is carried out among clusters.With the reputation mechanism and modified MAJORITY rule in the second level cooperation,the proposed scheme can not only relieve the influence of the shadowing,but also eliminate the impact of the PU emulation attack on a relatively large scale.Simulation results show that,in the scenarios with deep-shadowing or multiple attacked SUs,our proposed scheme achieves a better tradeoff between the system robustness and the energy saving compared with those conventionally cooperative sensing schemes.展开更多
文摘Aiming at the suppression of enemy air defense(SEAD)task under the complex and complicated combat sce-nario,the spatiotemporal cooperative path planning methods are studied in this paper.The major research contents include opti-mal path points generation,path smoothing and cooperative rendezvous.In the path points generation part,the path points availability testing algorithm and the path segments availability testing algorithm are designed,on this foundation,the swarm intelligence-based path point generation algorithm is utilized to generate the optimal path.In the path smoothing part,taking ter-minal attack angle constraint and maneuverability constraint into consideration,the Dubins curve is introduced to smooth the path segments.In cooperative rendezvous part,we take esti-mated time of arrival requirement constraint and flight speed range constraint into consideration,the speed control strategy and flight path control strategy are introduced,further,the decoupling scheme of the circling maneuver and detouring maneuver is designed,in this case,the maneuver ways,maneu-ver point,maneuver times,maneuver path and flight speed are determined.Finally,the simulation experiments are conducted and the acquired results reveal that the time-space cooperation of multiple unmanned aeriel vehicles(UAVs)is effectively real-ized,in this way,the combat situation suppression against the enemy can be realized in SEAD scenarios.
基金The authors would like to thank the reviewers for their de-tailed reviews and constructive comments, which have helped improve the quality of this paper. This work was supported by the National Natural Science Foundation of China under Grant No. 61101107 the Scientific Research and Innovation Plan for the Youth of BUPT under Grant No. 2011RC0305 the National International Science and Technology Cooperation Project under Grant No. 2010DFA11320.
文摘In order to save energy and make more efficient use of wireless channel, this article puts forward an energy saving cooperative relaying scheme which actuates the cooperative transmission only when the feedback from the destination indicates failure of the direct transmission. The proposed scheme selects the optimal relay and its corresponding transmission power in each time slot based on channel condition and residual energy with the objective of minimizing energy consumption and extending network lifetime. In the study, the finite-state Markov channel model is used to characterize the correlation structure of channel fading in wireless networks, and the procedure of relay selection and transmission power decision is formulated as a Markov decision process. Numerical and simulation results show that the proposed scheme consumes less energy and prolongs the network lifetime.
基金ACKNOWLEDGEMENT This work was partially supported by the Na- tional Natural Science Foundation of China under Grant No. 61071127 and the Science and Technology Department of Zhejiang Pro- vince under Grants No. 2012C01036-1, No. 2011R10035.
文摘Cooperative spectrum sensing in cognitive radio is investigated to improve the detection performance of Primary User(PU).Meanwhile,cluster-based hierarchical cooperation is introduced for reducing the overhead as well as maintaining a certain level of sensing performance.However,in existing hierarchically cooperative spectrum sensing algorithms,the robustness problem of the system is seldom considered.In this paper,we propose a reputation-based hierarchically cooperative spectrum sensing scheme in Cognitive Radio Networks(CRNs).Before spectrum sensing,clusters are grouped based on the location correlation coefficients of Secondary Users(SUs).In the proposed scheme,there are two levels of cooperation,the first one is perfonned within a cluster and the second one is carried out among clusters.With the reputation mechanism and modified MAJORITY rule in the second level cooperation,the proposed scheme can not only relieve the influence of the shadowing,but also eliminate the impact of the PU emulation attack on a relatively large scale.Simulation results show that,in the scenarios with deep-shadowing or multiple attacked SUs,our proposed scheme achieves a better tradeoff between the system robustness and the energy saving compared with those conventionally cooperative sensing schemes.
