Patent ID: 7315745
Filing Date: 2008-01-01
Classification: G01S

Abstract:
1. A method of estimating the time offsets between signals transmitted by plural transmitters of a communications network and received by a receiver attached to a terminal, the method comprising the steps of (a) creating a terminal section of a representation of the signals from the plural transmitters received by the receiver at the terminal; (b) creating a first section of a representation of the signal transmitted by a first of said transmitters, and creating a second section of a representation of the signal transmitted by a second of said transmitters, each of which sections overlaps in time with the terminal section; (c) using the first section, the second section and a set of signal parameters, including initial estimates of the time offsets between the first section and the terminal section and between the second section and the terminal section, to create a model of a section of a representation of the composite signal received by the receiver from the first and second transmitters; (d) comparing the model with the terminal section; (e) refining the set of signal parameters including the time offset estimates to minimise the difference between said model and the terminal section; and (f) adopting the time offsets in the refined parameter set used to minimise the difference between said model and the terminal section, as the estimated time offsets between the first section and the terminal section and between the second section and the terminal section.