基于平方位置误差下限的优化功率分配方案

摘要

在无线传感网络中，节点定位是基于位置的应用基本要求。然而，现多数文献仅关注定位精度，而忽略了能量消耗对定位精度的影响。为此，针对基于接收信号强度 RSSI（Received Signal Strength Indicator）定位方案，提出基于平方位置误差下限 SPEB （Squared Position Error Bound）的优化功率分配 SPEB-OPA（SPEB-Based Optimal Power Allocation）方案，目的在于最小化能量消耗。在 SPEB-OPA 算法中，将 SPEB 作为评定定位精度的参数，并推导出 SPEB 表达式，然后建立优化功率分配的目标函数，并考虑到锚节点位置存在误差。仿真结果表明，提出的 SPEB-OPA 方案极大地减少了功率消耗。当误差门限 T ＝8时，SPEB-OPA 方案的功率消耗比统一功率分配 UPA（Uniform Power allocation）方案减少至50％。%Sensor nodes positioning is a fundamental requirement of location-based applications in wireless sensor networks.However,now most of the literatures only focus on positioning accuracy,but the impact of energy consumption on positioning accuracy is overlooked.There-fore,for RSSI-based positioning scheme,we introduced an optimised power allocation scheme which is based on square position lower error bound (SPEB-OPA),aimed at minimising the energy consumption.In SPEB-OPA algorithm,we used SPEB as the parameter for estimating positioning accuracy,and deduced the SPEB expression.Then we set up the objective function of the optimised power allocation,and consid-ered the errors existed in positions of anchor nodes.Simulation results showed that the proposed SPEB-OPA scheme greatly decreased the power consumption.When the error threshold T =8,the power consumption of SPEB-OPA scheme was reduced to 50% of that of uniform power allocation (UPA)scheme.