Abstract: In respect of positioning, the RSSI is affected greatly by external factors, so it is hard to ensure the accuracy in either ranging or positioning. Due to the interference that is at both variance and mean levels, RSSI should be amended at the two levels. In the data acquisition stage of RSSI, a Gaussian model based on deviation (D-Gaussian) is developed to filter the interference at variance level so as to improve the availability of RSSI signal. Then, in the ranging stage, a dynamic window mechanism EWMA is introduced, i.e., the R-EWMA, to deal with the interference at mean level. Experimental results showed that the contradiction between positioning accuracy and the hardware costs in conventional positioning algorithm is moderated efficiently, thus reducing basically the error of RSSI positioning algorithm via processing RSSI properly.