基于RSSI测距的WiFi室内定位算法研究

Research on WiFi Indoor Positioning Algorithm Based on RSSI Ranging

考虑AP(接入点)部署高度对定位精度的影响,提出了一种消除高度影响的加权质心定位算法。首先对采集的RSSI(接收信号强度指示)进行高斯拟合和Kalman滤波,根据室内信号传播模型得出终端与AP的距离;然后用几何方法对垂直距离做了消除,得出AP和终端的平面距离;最后用消除高度影响的加权质心定位算法计算位置。对于多层建筑物,还提出了一种楼层识别方法,结合二维平面定位构成近三维室内定位算法。在实验楼内用以上方法进行楼层识别,识别率可达100%。在大型教室进行定位实验,结果表明:改进后的算法相比传统定位算法在精度和稳定性上都有一定的提高。

A weighted centroid positioning algorithm to eliminate the influence of altitude is proposed consider- ing the influence of AP（ access point） deployment height on positioning accuracy. Firstly, the RSSI signal is collected and processed by Gaussian fitting and Kalman filtering, and the distance between the terminal and the AP is obtained according to the indoor signal propagation model. Then, the vertical distance is eliminated by the geometric method, and the plane distance between the AP and the terminal is obtained. Finally, the position coordinate is calculated by the weighted centroid positioning algorithm to eliminate the influence of altitude. For a multi-storey building, a floor recognition method is proposed, which combines the 2D planar positioning to construct a near-3D indoor positioning algorithm. In the laboratory building, the floor is recognised with the a- bove methods and the recognition rate is 100%. In the large-scale classroom for positioning experiments, the re- sults show that the improved algorithm has a certain increase on the accuracy and stability compared with the traditional positioning algorithm.