| 摘要 |
<p>The present invention provides a method for determining synchronisation of a signal received in a global positioning system receiver and transmitted by a global positioning system satellite, wherein the method comprises the steps of transform coding (14) said received signal so as to transform said received signal from time domain to frequency domain coefficients, dividing respective (18) ones of said frequency domain coefficients by corresponding ones of transform coefficients of the expected transmitted signal associated with said satellite to provide corresponding transform value ratios, and deriving (20, 22) from respective transform value ratios corresponding scaled values of the time delay of the signal between the satellite and the receiver. The invention directs the search for synchronisation to a small set of chips thereby providing an indication of the identity of the synchronisation sequence. Thus the search for the synchronisation chip is more focused than the prior art method, which results in obtaining synchronisation on average more quickly and more efficiently than in the prior art.</p> |
