中文摘要：

为提高多信道认知无线电的吞吐量,提出采用交替方向优化联合分配次用户的频谱感知时间和子信道感知门限.基于＂先听后传＂的次用户帧结构,建立了感知时间和门限的优化分配模型.该模型在保证满足主用户通信需求和子信道频谱感知性能的前提下,最大化次用户各子信道的吞吐量总和.联合优化算法通过交替优化感知时间和门限能够获得模型的最优解.仿真结果表明：存在最优的感知时间和门限最大化次用户的吞吐量,并且相比之前的方案,联合分配能够提高次用户的吞吐量.

英文摘要：

In order to improve the throughput of multichannel CR, a joint allocation of spectrum sensing time and subchannel sensing threshold based on the alternating direction optimization is proposed. Based on the SU＇ s listen- before-transmit frame structure, an optimized allocation model is built to maximize the aggregate throughput of the SU over all the subehannels, providing that the communication demand of the PU and the performance of the subehannel spectrum sensing are guaranteed. The joint optimization algorithm is proposed to obtain the optimal solutions to the model through alternately optimizing sensing time and threshold. The simulation results show that there exist the optimal sensing time and threshold that maximize the SU＇ s throughput, and compared to the previous schemes, the joint allocation can improve the SU＇ s throughput.