CALIBRATION FOR WIRELESS LOCATION SYSTEM

摘要

An external calibration method comprises the steps of transmitting a first reference signal from a reference transmitter; receiving the first reference signal at first and second receiver systems: (10-2A-10-2C); determining a first error value by comparing a measured TDOA value with a theoretical TDOA value associated with the known locations of the receiver systems and the known location of the reference transmitter; and utilizing the first error value to correct subsequent TDOA measurements associated with a mobile transmitter to be located. An internal calibration method comprises the steps of injecting a comb signal into the first receiver system: utilizing the comb signal to obtain an estimate of the manner in which the transfer function varies across the bandwidth of the first receiver system; and utilizing the estimate to mitigate the effects of the variation of the first transfer function on the time measurement made by the first receiver system.