User-oriented data acquisition chain task planningalgorithm for operationally responsive space satellite

With the development of operationally responsive space（ORS） and on-board processing techniques, the end users canreceive the observation data from the ORS satellite directly. Tosatisfy the demand for reducing the requirements-tasking-effectscycle from one day to hours, the various resources of the wholedata acquisition chain （including satellites, ground stations, dataprocessing centers, users, etc.） should be taken into an overallconsideration, and the traditional batch task planning mode shouldbe transformed into the user-oriented task planning mode. Consideringthere are many approaches for data acquisition due tothe new techniques of ORS satellite, the data acquisition chaintask planning problem for ORS satellite can be seen as the multimodalroute planning problem. Thereby, a framework is presentedusing label-constrained shortest path technique with the conflictresolution. To apply this framework to solve the ORS satellite taskplanning problem, the preprocessing and the conflict resolutionstrategies are discussed in detail. Based on the above work, theuser-oriented data acquisition chain task planning algorithm forORS satellite is proposed. The exact solution can be obtainedin polynomial time using the proposed algorithm. The simulationexperiments validate the feasibility and the adaptability of the proposedapproach.

Partial cooperative spectrum sensing schedule in cognitive network

Cognitive radio has emerged as a promising technology for maximizing the utilization efficiency of the limited spectrum resources while accommodating the increasing amount of services and applications in wireless networks. One of the most important and critical components of the cognitive radio is spectrum sensing and accordingly, detection of primary users. Considering the hardware constraints existing in cognitive devices, based on the coarse estimation of channel occupancy, partial cooperative spectrum sensing with adaptive spectrum schedule scheme is proposed to increase the possibility to discover more spectrum opportunities promptly. Simulation results show the gain of sensing performance and the energy-saving feature of partial spectrum sensing. Special security scheme is designed to protect the reliability of sensing result from the false message attack. For the scenarios tested, the proposed scheme is shown to increase opportunities by up to 15 percent.