一种视距与非视距混合环境下RSS定位方法

Research on the Positioning Technology of RSS in the Mixed Environment of the Line of Sight and Non-line of Sight

针对当前视距与非视距混合环境下无线定位精度不高且结果不太稳定问题,提出一种基于接收信号强度的动态定位方法.该方法采用混合高斯模型来同时刻画视距与非视距传播的影响,克服了现有方法中视距与非视距传播识别的难题,并利用动态期望最大算法来实时调整模型参数,以适应环境的时变特性.进一步,考虑到实际定位中测试位置几何关系对定位精度的影响,提出了基于最佳几何精度衰减因子组合的测试点选取方法.仿真实验表明,在视距与非视距混合环境下该方法不仅具有较高的定位精度,而且能够适应环境的动态变化.

A dynamic positioning method based on the received signal strength( RSS) is proposed to solve the problem of low accuracy and low robustness of wireless location in the mixed environment of the line of sight( LOS) and non line of sight( NLOS). This method adopts a mixed Gauss model to describe the communicative effects of both the LOS and NLOS environment to overcome problem of identifying them existing in current methods. Morever,a dynamic expectation maximum( DEM) algorithm is presented for real-time adjust of the model parameters,which can be suitable for environment timevarying characteristics. Furthermore,considering the influence on locating accuracy caused by the geometric relation of test positions,a method of test points selection is proposed on the basis of geometric dilution of precision( GDOP). The simulation results show that the algorithm presented in this paper can not only have a high positioning accuracy,but also fit the dynamic changes of the environment.