多天线认知系统中最优协作用户数的选择研究

The Research of Optimal Number of Collaboration Users in Multi-antenna CR system

针对非理想控制信道传输错误对认知系统中多天线多用户协作频谱感知性能影响的问题,提出一种使得认知系统误检概率最小的最优协作用户数选择方案,并推导给出其闭式表达式。该方案首先根据单根天线错误检测概率最小的原则推导出认知用户单根天线最优的判决门限。然后利用"K秩"准则对多天线进行合并,根据认知用户错误检测概率最小的原则推导出最优的"K"值。最后根据认知系统误检概率最小的原则推导出最优的协作感知用户数。通过仿真验证了该方案理论的正确性,并分析给出了控制信道错误概率对认知系统检测性能的影响。相比于传统的协作检测算法,本方案具有更好的检测性能。

In view of the effect on the sensing performance of multi-antenna multi-user in cognitive radio （CR） system by imperfect control channel, an optimal selection scheme of the number of collaboration users that minimizes the error de- tection probability of CR system is proposed, and the closed expression of the optimal number of collaboration users is dem- onstrated. The algorithm firstly analyzes the decision threshold of each antenna of CR user based on the minimal error de- tection probability. Secondly, ＂K＂ rank rule to merge the multi-antenna is adopted, and the optimal ＂K＂ value is deduced based on minimal error detection probability of each CR user. Thirdly, the optimal number of collaboration users is deduced based on minimal error detection probability of the system. The validity of theoretical derivation is proved through simula- tion, and the effect on CR system by the error probability of control channel is analyzed. From a detection performance per- spective, the proposed ＇scheme is advantageous comparing with conventional collaboration detection algorithms.