Hybrid mobile station location methods for single base station multiple-input multipleoutput communication systems

Based on the joint estimations of time of arrival (TOA), angle of arrival (AOA) and angle of departure (AOD) of two or more single-bounced multipaths from a single base station (BS) and an mobile station (MS) in an MIMO system, two schemes, closed-form total least squares solution (CF-TLS) and constraint-based grid-search approach (CB-GSA) are presented to locate an MS. The CF-TLS method is time saving and provides good location accuracy when two or more resolvable single-bounced multipaths are available. However, the CB-GSA method always provides better location accuracy than the CF-TLS method at a cost of large computational burden. When only two single-bounced multipaths can be observed or the range and angle measurement errors are large, the location accuracy of the CB-GSA method outperforms that of the CF-TLS method significantly. By executing the CF-TLS method to give an initial estimation of an MS position, the search area of the CB-GSA method is narrowed, and the location time is significantly reduced. Simulations verify the effectiveness of the two proposed methods.