认知网中多时隙联合频谱感知和功率分配

为了降低认知无线网中认知用户对主用户的干扰,并为了最大化系统的认知吞吐量,提出了一种多时隙频谱感知和功率分配的联合优化方案。该方案将系统的每个帧分为若干个时隙,每个时隙分别进行频谱感知,通过合并每个时隙的感知结果,有效的提高了系统的检测精度,降低了系统的干扰概率。同时理论分析了感知时间与传输功率分配方案,发现两者都存在最优分配解,在约束认知用户检测概率与传输功率的基础上,将吞吐量描述为关于感知时间与功率的多约束优化问题,通过设计联合迭代算法对认知吞吐量进行了联合优化并获得了最优感知时间与最优传输功率分配。仿真结果表明,所提联合优化方案吞吐量性能最接近理论最优方案,并可通过牺牲部分吞吐量性能降低系统干扰概率,且复杂度较低。

Multi-slot Cooperative Spectrum Sensing and Power Allocation in Cognitive Network

In cognitive network, in order to decrease the interference to the primary user caused by the cognitive user and maximize the throughput of the cognitive user, a multi-slot spectrum sensing and power allocation optimization scheme which is proposed. Each frame of the system is divided into several time slots, and the cognitive user can sense the primary user in each time slot. Combing the time slot results could effectively improve the detection probability and reduce the probability of the system interference. Meanwhile, the optimal sensing time and power allocation scheme are analyzed in theory. Based on the constraints of the detection probability and the total transmission power, the cognitive throughput is formulated as an optimization problem with multiple constraints. In the end, the optimal sensing time and power allocation are obtained by the joint iterative algorithm. The simulation results show that the proposed joint optimization algorithm is closed to the optimal scheme and can efficiently reduce the system interference by sacrificing the partial throughput performance, and it also has lower complexity.