Cognitive Radio(CR) has been proposed as a system-level means to improve the spectrum utilization efficiency.The most significant premise for CR networks is to avoid harmful interference to the licensed users.Therefor...Cognitive Radio(CR) has been proposed as a system-level means to improve the spectrum utilization efficiency.The most significant premise for CR networks is to avoid harmful interference to the licensed users.Therefore,it is very important to estimate the potential inter-ference introduced by the deployment of CR networks so that CR networks can be coexistence with Licensed User(LU) networks by designing proper system parameters.In this paper,two statistical models of potential interference due to CR networks are developed based on transmitter and receiver oriented spectrum sensing schemes,respectively.The approximate probability dis-tributions of aggregate interference introduced by CR networks are then derived with respect to the obtained models.With the help of these probability distributions,a method is further pre-sented to get the critical system parameter,i.e.,sensing distance and user density of the CR networks,so that the introduced interference can be controlled to predefined level.Numerical results validate the proposed interference estimation method and confirm the effectiveness of in-terference distribution based system parameter design.展开更多
In this article, a new approach for modeling multiinput multi-output （MIMO） systems with unknown nonlinear interference is introduced. The semiparametric theory based MIMO model is established, and Kernel estimation...In this article, a new approach for modeling multiinput multi-output （MIMO） systems with unknown nonlinear interference is introduced. The semiparametric theory based MIMO model is established, and Kernel estimation is applied to combat the nonlinear interference. Furthermore, we derive MIMO capacity for these systems and explore the asymptotic properties of the new channel matrix via theoretical analysis. The simulation results show that the semiparametric theory based modeling and kernel estimation are valid to combat this kind of interference.展开更多
基金Supported by the High-tech Research and Development Program (863 Program) of China (No. 2009AA011801)the National Basic Research Program (973 Program) of China (No. 2009CB320405)+1 种基金the Foundation Project of National Key Laboratory of Science and Technology on Communications (No. 9140C0202061004)the Fundamental Research Funds for the Central Universities (No. ZYGX2009X002)
文摘Cognitive Radio(CR) has been proposed as a system-level means to improve the spectrum utilization efficiency.The most significant premise for CR networks is to avoid harmful interference to the licensed users.Therefore,it is very important to estimate the potential inter-ference introduced by the deployment of CR networks so that CR networks can be coexistence with Licensed User(LU) networks by designing proper system parameters.In this paper,two statistical models of potential interference due to CR networks are developed based on transmitter and receiver oriented spectrum sensing schemes,respectively.The approximate probability dis-tributions of aggregate interference introduced by CR networks are then derived with respect to the obtained models.With the help of these probability distributions,a method is further pre-sented to get the critical system parameter,i.e.,sensing distance and user density of the CR networks,so that the introduced interference can be controlled to predefined level.Numerical results validate the proposed interference estimation method and confirm the effectiveness of in-terference distribution based system parameter design.
基金the National Natural Science Foundation of China（60496312）；the Hi-Tech Research and Development Program of China （2006AA01Z260）；the Program for New Century Excellent Talents in University（NCET-05-116）.
文摘In this article, a new approach for modeling multiinput multi-output （MIMO） systems with unknown nonlinear interference is introduced. The semiparametric theory based MIMO model is established, and Kernel estimation is applied to combat the nonlinear interference. Furthermore, we derive MIMO capacity for these systems and explore the asymptotic properties of the new channel matrix via theoretical analysis. The simulation results show that the semiparametric theory based modeling and kernel estimation are valid to combat this kind of interference.
