能量协作下中继系统性能推导及仿真分析

Derivation of the performance of the relay system and simulation analysis of the system under energy cooperation

由于无线传感器网络频繁使用中继节点带来了能量空洞问题,所以提出了一种单中继通信下基于能量协作的降低中断概率和减少能量消耗的方案。该方案假设中继节点分布为泊松点过程,并且源节点和中继节点能够从环境中收集能量。首先,在发送数据的初始阶段,源节点依据自身电池储能状态有概率地选择直通链路或者中继链路,再结合中继节点位置与电池稳态分布,利用信噪比推导出系统的中断概率表达式;而后,建立以消耗能量值最小化为目标函数的最优化模型,通过粒子群算法求出使系统消耗能量最少时的参数分配。由仿真结果可知,与原有方案相比,所提出的模型能获得更低的中断概率,且证明了能量协作可明显地减少通信过程中的能量消耗。

Aiming at the problem of the energy hole caused by the frequent use of relay nodes in wireless sensor networks,a single relay system based on energy cooperation is proposed.The scheme assumes that the distribution position of the relay node obeys the Poisson point process, and that the source node and the relay node can harvest energy from the environment. When the source transmits a signal to the relay, some energy is also sent by the source to the relay. According to the battery storage state the source transmits its data to the destination either directly or cooperatively by the relay. Combined with the position of the relay node and the steady-state distribution of the battery, the system outage probability is derived. The optimization model is established to minimize the system consumed energy. The particle swarm algorithm is used to get the optimal system parameters. Simulation results verify the performance of the proposed model. It is also proved that energy cooperation can significantly reduce the energy loss in the communication link.