为了提高宽带认知无线电的吞吐量,提出了能量检测时间和子信道传输功率的联合分配.针对认知无线电的传输帧结构,联合分配被建立成关于时间和功率的多变量优化问题,即在保证各子信道的虚警概率、检测概率及总功率满足需求的基础上,最大化认知无线电的吞吐量.通过采用二分搜索算法和交替方向优化算法,获得了优化问题的最优解.联合分配属于凸优化问题,因此存在特定的时间和功率,最大化认知无线电的吞吐量.实验结果表明:在瑞利衰落信道下,相比感知——吞吐量折中方案,联合分配能够提高认知无线电的吞吐量.
To improve the throughput of wideband cognitive radio (CR), a joint allocation of energy detection time and subchannel transmission power was proposed. The joint allocation was formulated as a multi-variable optimization problem based on the transmission frame structure of CR, which max- imized the throughput of CR while keeping the probabilities of false alarm and detection in each sub- channel and the aggregate power satisfying the demands. The optimal solution of the optimization problem was obtained through binary search algorithm and alternant direction optimization algorithm. As the joint allocation is convex optimization, there exist specific detection time and power that maxi- mize the throughput of CR. Compared to the sensing-throughput tradeoff scheme, the joint allocation can improve the throughput of CR in rayleigh fading channel.