Because of the specific of underwater acoustic channel,spectrum sensing entails many difficulties in cognitive underwater acoustic communication( CUAC) networks, such as severe frequency-dependent attenuation and low ...Because of the specific of underwater acoustic channel,spectrum sensing entails many difficulties in cognitive underwater acoustic communication( CUAC) networks, such as severe frequency-dependent attenuation and low signal-to-noise ratios. To overcome these problems, two cooperative compressive spectrum sensing( CCSS) schemes are proposed for different scenarios( with and without channel state information). To strengthen collaboration among secondary users( SUs),cognitive central node( CCN) is provided to collect data from SUs. Thus,the proposed schemes can obtain spatial diversity gains and exploit joint sparse structure to improve the performance of spectrum sensing. Since the channel occupancy is sparse,we formulate the spectrum sensing problems into sparse vector recovery problems,and then present two CCSS algorithms based on path-wise coordinate optimization( PCO) and multi-task Bayesian compressive sensing( MT-BCS),respectively.Simulation results corroborate the effectiveness of the proposed methods in detecting the spectrum holes in underwater acoustic environment.展开更多
针对指挥信息系统(command,control,communications,computers,intelligence,surveillance and reconnaissance,C4ISR)服务部署分散、作战平台计算/存储资源有限、演化实时性要求高的特点,基于分层结构设计了系统状态分布式监控与演化...针对指挥信息系统(command,control,communications,computers,intelligence,surveillance and reconnaissance,C4ISR)服务部署分散、作战平台计算/存储资源有限、演化实时性要求高的特点,基于分层结构设计了系统状态分布式监控与演化总体架构,并在该架构下提出了一种服务部署方案层级动态调整方法。通过定义信息流转长度与方案调整代价设计了服务部署调整方案的数学优化模型,针对部署方案中同时包含服务部署位置和信息流转路径的特点,将成对交换思想、最短路径规划与m-best策略相结合提出了一种贪心求解算法,以实现调整方案的快速生成。实验证明,该方法能够在保证系统信息流转效能的同时有效控制系统的演化范围,适用于执行任务过程中服务部署方案的敏捷调整。展开更多
基金National Natural Science Foundations of China(Nos.60872073,51075068,60975017,61301219)Doctoral Fund of Ministry of Education,China(No.20110092130004)
文摘Because of the specific of underwater acoustic channel,spectrum sensing entails many difficulties in cognitive underwater acoustic communication( CUAC) networks, such as severe frequency-dependent attenuation and low signal-to-noise ratios. To overcome these problems, two cooperative compressive spectrum sensing( CCSS) schemes are proposed for different scenarios( with and without channel state information). To strengthen collaboration among secondary users( SUs),cognitive central node( CCN) is provided to collect data from SUs. Thus,the proposed schemes can obtain spatial diversity gains and exploit joint sparse structure to improve the performance of spectrum sensing. Since the channel occupancy is sparse,we formulate the spectrum sensing problems into sparse vector recovery problems,and then present two CCSS algorithms based on path-wise coordinate optimization( PCO) and multi-task Bayesian compressive sensing( MT-BCS),respectively.Simulation results corroborate the effectiveness of the proposed methods in detecting the spectrum holes in underwater acoustic environment.
文摘针对指挥信息系统(command,control,communications,computers,intelligence,surveillance and reconnaissance,C4ISR)服务部署分散、作战平台计算/存储资源有限、演化实时性要求高的特点,基于分层结构设计了系统状态分布式监控与演化总体架构,并在该架构下提出了一种服务部署方案层级动态调整方法。通过定义信息流转长度与方案调整代价设计了服务部署调整方案的数学优化模型,针对部署方案中同时包含服务部署位置和信息流转路径的特点,将成对交换思想、最短路径规划与m-best策略相结合提出了一种贪心求解算法,以实现调整方案的快速生成。实验证明,该方法能够在保证系统信息流转效能的同时有效控制系统的演化范围,适用于执行任务过程中服务部署方案的敏捷调整。
