Base station timing derived from wireless terminal information

摘要

A technique for deriving timing information across wireless base stations is disclosed. After initializing values for base station time-offset parameters, a server acquires reference coordinates of a wireless terminal, which are provided from an independent source, and also acquires values for one or more time-of-occurrences of events associated with signals that travel between the wireless terminal and the base stations. The server generates predicted coordinates of the wireless terminal, based in part on the current time-offset values, by using trilateration. The server then generates updated time-offset values, based on a method of least squares, in which each residual is a difference between the reference and predicted coordinates of each wireless terminal location, for one or more wireless terminals. The server modifies the time-offset values so as to minimize the least-squares function.

主权项

1. A method comprising:
receiving, by a data processing system:
(1) a first reference coordinate, {circumflex over (x)}1, that represents a reference location of a wireless terminal, and(2) a time of occurrence of an event associated with a signal traveling between the wireless terminal and a first base station; generating, by the data processing system, a first predicted coordinate, {tilde over (x)}1, that represents a predicted location of the wireless terminal, based on:
(1) the location of the first base station,(2) the time of occurrence, and(3) a first value of a time offset at the first base station, τ11, wherein the time offset characterizes timing at the first base station; generating, by the data processing system, a second value of the time offset, τ21, based on modifying first value τ11 dependent upon a function that is defined at least in part by a first expression that comprises {circumflex over (x)}1 and {tilde over (x)}1; and outputting, by the data processing system, the second value of the time offset, τ21, to an application for adjusting one or more base station clocks.