Abstract: Received signal strength index (RSSI) based ranging technology is widely used in wireless sensor network (WSN)positioning technology,because of its low cost and low complexity.The RSSI value is easily affected by the environment,even if the RSSI value collected at the same location is subject to fluctuations and abrupt changes,thus the ranging error is large.Based on the analysis of RSSI ranging principle and the current common filtering algorithm,this paper proposed a hybrid filtering algorithm based on Dixon test filtering,median filtering and gaussian filtering by comparing the effect of single filtering through experiments and taking advantage of the significant effect of filtering.Firstly,the linear regression algorithm is used to optimize the parameters of the RSSI ranging model,and then the optimal value is obtained by filtering the abnormal RSSI value through the hybrid filter to achieve accurate ranging.The experimental results show that compared with a single filtering algorithm,the hybrid filtering algorithm can significantly reduce the fluctuation of the RSSI value,and eliminate the abnormal RSSI value more effectively.The filtered RSSI value is closer to the ideal value,and the ranging error is smaller.It proves that the hybrid filtering algorithm is effective and feasible

Key words: Hybrid filtering algorithm, Ranging algorithm, Received signal strength index, Wireless sensor network