Impact of MIMO Technique on TOA-Based Location Estimation

In a cellular system, Multiple-Input/Multiple-Output (MIMO) technique increases the number of links for not only spatially multiplexing data to transmit/receive but also measuring the distance between a base station (BS) and a mobile station (MS) at the same time. Therefore, if the MIMO technique is applied to a system-based location estimation, it must enhance the location accuracy of a MS. This paper examines the impact of MIMO technique on the estimation accuracy of a Time Of Arrival (TOA)-based location estimation in a cellular system and proposes three location estimation methods for a 2 × 2 MIMO case. Computer simulation results on location estimation error reveal that a minimal selection method, which is simple but rich in some approximation errors by dealing with both BSs and MS as if they were equipped with a single antenna, respectively, performs best among the three methods and can significantly decrease the location estimation error.