智能空间中RSSI定位问题研究

Research on RSSI-based Location in Smart Space

定位服务是智能空间所必须提供的基本服务,而定位精度的高低在很大程度上取决于距离测量精度.本文分析了现有无线测距技术运用到智能空间中存在的诸多问题,结合无线传感器节点的硬件特性,选择了基于RSSI的定位技术,提出了三种基于RSSI定位的实现机制:最小二乘曲线拟合法,信号强度分布法以及混合定位法.在此基础上,针对所提出的三种定位技术从定位计算量、定位误差等方面进行了实验测试与对比分析.结果表明,混合定位法所需的计算量小、定位精度高,能更好地满足于资源受限环境下的定位服务需求.由此可见,借助于本文提出的混合定位法,结合适当的迭代定位算法可以有效地应用于实际系统的定位.

Location is one of the fundamental services provided by smart space,and the location precision is mainly decided by the accuracy in distance measurement. However, the current wireless location technology applying into smart space brings on a series of problems. Considering the hardware characteristics of current wireless sensor nodes, the paper selects the location mechanism based on RSSI, and puts forward three methods： Least-Square Curve Fitting Method, Signal Strength Distribution Method and Hybrid Location Method. Then the paper tests performances of the three methods from location cost and location error. Seen from test results, the Hybrid Location Method which need little computing amount and has high precision is better able to meet the requirement of positioning services under the resource-constrained environment. It is proved that with appropriate iterative location algorithms, the Hybrid Location Method above can be effectively used in practical positioning applications.