NULL-SPACE PROJECTION AND WATERFILLING RESOURCE ALLOCATION IN MULTI-ANTENNA COGNITIVE RADIO NETWORKS  

作　　者：Rong Mei Zhu Shihua 

机构地区：[1]Department of Information and Communication Engineering,Xi＇an Jiaotong University, Xi＇an 710049,China

出　　处：《Journal of Electronics(China)》2010年第5期701-707,共7页电子科学学刊（英文版）

摘　　要：Cognitive Radio(CR) is a promising technique for the next generation mobile communi-cation system for its capability to solve the conflicts between the scarcity and underutilization of spectrum.In this paper,aiming at maximizing the system capacity of a multi-antenna CR system on the premise that avoid interference to the primary system in the same band simultaneously,a resource allocation method which is able to avoid interference between PRimary(PR) and CR users by pro-jecting the transmit signals of CR users on the null space of the PR users' channels is proposed.CR users with better channel condition are selected,and the interference from CR system to PR users can be removed completely by projecting the transmit signals of CR system on the null-space of PR users' channels.Parallel sub-channels are constructed for CR users through Singular Value Decomposition(SVD).At last,waterfilling is also adopted to increase the CR users' capacity.Simulation result demonstrates that compared with existing methods,our method can improve the achievable sum rate of CR users as well as reduce the outage probability of PR users.Cognitive Radio（CR） is a promising technique for the next generation mobile communi-cation system for its capability to solve the conflicts between the scarcity and underutilization of spectrum.In this paper,aiming at maximizing the system capacity of a multi-antenna CR system on the premise that avoid interference to the primary system in the same band simultaneously,a resource allocation method which is able to avoid interference between PRimary（PR） and CR users by pro-jecting the transmit signals of CR users on the null space of the PR users’ channels is proposed.CR users with better channel condition are selected,and the interference from CR system to PR users can be removed completely by projecting the transmit signals of CR system on the null-space of PR users＇ channels.Parallel sub-channels are constructed for CR users through Singular Value Decomposition（SVD）.At last,waterfilling is also adopted to increase the CR users’ capacity.Simulation result demonstrates that compared with existing methods,our method can improve the achievable sum rate of CR users as well as reduce the outage probability of PR users.

关 键 词：Cognitive Radio (CR) network Resource allocation Null-space projection Waterfilling 

分 类 号：TN92[电子电信—通信与信息系统]