Algorithm For Eliminate The Positioning NLOS Error Based On Building Structure

NLOS error is the main reason to affect the accuracy of the positioning system, especially in the indoor positioning system, non-line-of-sight propagation caused by the architectural structure of the building will make the error of receiver signal measured value exist, eventually leading to the great deviation between positioning result and the real coordinates. Through learning the existing method of eliminating NLOS error and understanding the existing positioning system, we found that the existing NLOS error elimination algorithm will estimated the specific deviation caused by NLOS error after confirmed the signal error exsit, by using the statistical properties. it is difficult to get the specific amount of the NLOS error when errors in high density. thus leading to the existing indoor positioning system is easy to be affected by interior architecture structure, and the accuracy decline sharply when signal go through the wall. Therefore, it is necessary to study an algorithm which can calculate the size of the NLOS error caused by the building structure accurately, while can be used in the indoor environment. then improve the accuracy of indoor positioning by eliminating the precise NLOS error.In this paper, we build a model based on the building structure, construct a structure matrix to represent wall of different types building structure; we analyzes the effect of building structure on the signal spreading, and build a error model of building structure based on measurement of the TOA and RSSI value of signal.Then, it proposed a NLOS error elimination algorithm based on the building structure by using the topology structure and error model of the building structure. This algorithm combined the existing localization algorithms and it's properties to determine the scope of the error, using the energy loss model and the error range segmentation to estimated the NLOS error of TOA signal, then input the corrected TOA value into the localization algorithm, to calculate the accurate coordinate.Finally, the paper analysis, verify the error model and NLOS error elimination algorithm based on architecture structure by using MATLAB software. Compared with other error model, It can use GTRs positioning algorithm to get higher coordinate precision based on the error model of building structure; After using the NLOS error elimination algorithm of the building structure in the therory,The positioning accuracy of each Model were improved, It increased by 47.94%, the model accuracy of traditional Gaussian model and logarithmic were increased by 20.5% and 25.84%. The algorithm has obvious improvement in positioning accuracy, having a certain practicality.