An AOA assisted TOA positioning system

In this paper, time of arrival (TOA) and angle of arrival (AOA) errors in four typical cellular environments are analyzed and modeled. Based on the analysis, a hybrid TOA/AOA positioning (HTAP) algorithm, which utilizes TOA and AOA information delivered by serving base stations (BS), is proposed. The performance of the related positioning algorithms is simulated. It is shown that when the MS is close to the serving BS, HTAP will produce an accurate location estimate. When MS is far from the serving BS, the location estimate obtained by HTAP can be used as an initial location in our system to help a least square (LS) algorithm converge easily. When there are more than three TOA detected, weights and TOA numbers used in the LS algorithm should be dynamically adjusted according to the distance between MS and serving BS and the propagation environment for better positioning performance.