认知传感网络的信能无线传输优化

Optimization of Signal Energy Wireless Transmission of Cognitive Sensor Network

针对目前无线传感网络频谱资源匮乏、能源供给不足等问题,构建了一种新型的认知多播无线传感网络,并研究适用于该网络的信能协同传输问题,提出一种更有效的能量收集方案,从而解决认知传感网络中能量不足的问题;该方案以网络中所有次级用户收集到的和能量为优化目标,结合多播技术,在满足用户的服务质量要求、限制次用户对主用户的干扰和保证次级发射器的发射功率的约束下,构建了一种非线性的非凸优化问题;其中针对原始的非凸优化问题,提出一种基于半正定松弛的算法,将其转化为可直接求解的凸优化问题,从而延长网络的生存周期;并在该优化问题的基础上进一步提出一种基于序贯参数凸逼近技术的优化算法,以降低该系统复杂度;最后将研究结果用Matlab仿真实现,仿真结果表明,文章所提的算法和传统的信能同传技术相比,有效提高了次用户能量收集的性能。

Aiming at the current shortages of spectrum resources and insufficient energy supply in wireless sensor networks,a new type of cognitive multicast wireless sensor network is constructed,and the problem of coordinated transmission of information and energy is studied to be suitable for this network,and a more effective method of energy harvesting scheme is proposed to solve the problem of insufficient energy in cognitive sensor networks.This scheme takes the energy collected by all secondary users in the network as the optimization goal,and the multicast technology is combined to meet the user's service quality requirements,the interference of the secondary users is limited to the primary user,and the constraints of the transmit power of the secondary transmitter is ensured,a nonlinear non-convex optimization problem is constructed.Among them,for the original non-convex optimization problem,an algorithm based on semi-positive definite relaxation is proposed,which is transformed into a convex optimization problem that can be solved directly,so the life cycle of the network is prolonged;And based on the optimization problem and the sequential parameter convex approximation technique,an optimization algorithm is further proposed o to reduce the complexity of the system.Finally,the research results are realized by Matlab simulation.The simulation results show that,compared with the traditional simultaneous transmission of signal and energy technology,the algorithm proposed in this paper can effectively improve the performance of energy harvesting of secondary users.