Patent ID: 7151940
Filing Date: 2006-12-19
Classification: G01S,H04W

Abstract:
1. A method for increasing accuracy for locating a cellular mobile station in an urban area, comprising the following steps: 1) determining whether there is any synchronous measurement request, and if yes, initiating the synchronous measuring management for an assistant locating apparatus (including opening and closing transmission of round-trip delay (RTD) measuring pilot frequency); otherwise proceeding to the next step; 2) determining whether there is any locating request, and if yes, determining approximate location of the mobile station to be located with time of arrival, time difference of arrival (TDOA) and sector information of a base station; otherwise returning to step 1; 3) determining whether to open or close transmission of locating pilot frequency from an adjacent assistant locating apparatus according to the approximate location of the mobile station; 4) if an assistant locating pilot frequency is opened, measuring the TDOA again, and then determining whether the measurement for the mobile station to be located is finished; if yes, closing the transmission of the locating pilot frequency from the assistant locating apparatus; otherwise repeating the determination step; 5) searching for and processing multi-paths and identifying Non-Line-Of-Sight (NLOS) paths according to channel codes of the mobile station to be located, and requesting the assistant locating apparatus to report NLOS path identification result; and 6) estimating the location of the mobile station with the measurement of assistant pilot frequency signals and NLOS path identification result to obtain a more accurate location of the mobile station.