Cognitive information metrics for cognitive wireless networks

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.