Delay matching and NLOS error mitigation in CDMA wireless location systems

In CDMA wireless location systems,the incorrect delay matching and the non-line-of-sight(NLOS)error seriously limit the localization performance.Due to the difference between the PN-offset of two different bases is the integer multiple of 64 chips,a shifted matching method is presented to match the delay parameters with the base station.In order to mitigate the NLOS error,a function based on the assumed NLOS bases is proposed,and the target location can be obtained by weighted average of the function.Computer simulations are given to illustrate the effectiveness of the proposed method.Furthermore,if the number of the NLOS bases detected by the proposed function is relatively small,the location accuracy can be better improved by using the Taylor series expansion.