拟建设的新疆奇台110 m全可动射电望远镜(Qi Tai Radio Telescope, QTT)具有极高的系统灵敏度,良好的无线电环境是QTT科学产出的重要保证.为确保QTT建设阶段台址各类电磁干扰的有效监测,开发了自动化、高可靠性电波环境监测系统,该系统...拟建设的新疆奇台110 m全可动射电望远镜(Qi Tai Radio Telescope, QTT)具有极高的系统灵敏度,良好的无线电环境是QTT科学产出的重要保证.为确保QTT建设阶段台址各类电磁干扰的有效监测,开发了自动化、高可靠性电波环境监测系统,该系统开发依据需求分析,采用高紧凑性微波器件集成方案;系统性能实测结果表明6 GHz以下频段系统增益大于40 dB,噪声系数小于2 dB;7 GHz以下频段测量不确定度小于1.49 dB.同时,该系统考虑了户外防护、防雷及电磁兼容设计,具有较高的可靠性.另外,开发了自动化电波环境测量及监控软件和基于HDF5的数据处理及成图软件,实现自动化频谱监测及高效数据处理及分析.展开更多
Considering the dynamic changes and uncertainty features of the radio environment in cognitive wireless networks(CWNs),the environment cognition ability is critical for the performance evaluation of CWNs design and op...Considering the dynamic changes and uncertainty features of the radio environment in cognitive wireless networks(CWNs),the environment cognition ability is critical for the performance evaluation of CWNs design and optimization.However,there are no effective metrics to evaluate the ability and gain of information cognition in CWNs from an information theory perspective.Therefore,the novel cognitive information concept is proposed and defined as a metric to evaluate the uncertainty of both the internal and external environments of one system that can be removed by other systems or nodes using cognitive radio techniques.As an intelligent wireless communication system that is aware of its surrounding radio,network,and user multi-domains environment,the more cognitive information it achieves,the higher level cognitive capability it is.In this paper,we define and analyze the mathematical features of cognitive information.Results reveal that the increase of cognitive information can improve the spectrum efficiency and reduce the interference probability simultaneously in CWNs.Thus cognitive information can be regarded as a metric for CWNs optimization.Finally,we apply the theory of cognitive information in the parameters optimization in energy detection and cooperative spectrum sensing.展开更多
基金supported by the National Natural Science Foundation of China (61227801,61201152,61121001)the Major State Basic Research Development Program of China (973 Program,2009CB320400)+2 种基金the National Science and Technology Major Project (2012ZX03003006)the Program for New Century Excellent Talents in University (NCET-01-0259)the Fundamental Research Funds for the Central Universities (2013RC0106)
文摘Considering the dynamic changes and uncertainty features of the radio environment in cognitive wireless networks(CWNs),the environment cognition ability is critical for the performance evaluation of CWNs design and optimization.However,there are no effective metrics to evaluate the ability and gain of information cognition in CWNs from an information theory perspective.Therefore,the novel cognitive information concept is proposed and defined as a metric to evaluate the uncertainty of both the internal and external environments of one system that can be removed by other systems or nodes using cognitive radio techniques.As an intelligent wireless communication system that is aware of its surrounding radio,network,and user multi-domains environment,the more cognitive information it achieves,the higher level cognitive capability it is.In this paper,we define and analyze the mathematical features of cognitive information.Results reveal that the increase of cognitive information can improve the spectrum efficiency and reduce the interference probability simultaneously in CWNs.Thus cognitive information can be regarded as a metric for CWNs optimization.Finally,we apply the theory of cognitive information in the parameters optimization in energy detection and cooperative spectrum sensing.
