A method of despreading GPS spread spectrum signals containing pseudorandom noise
(PRN) code sequences and received by a GPS receiver (24) is disclosed together
with a GPS receiver (24) and a mobile communications device (MS1)
(especially a mobile cellular telephone) for the same. The method comprises the
steps of providing Doppler information relating to an estimate of the variation
in Doppler shift as observed on the target signal by the GPS receiver and which
is attributable to the motion of the GPS satellite; and correlating the target
signal with a reference signal containing corresponding PRN code sequences, wherein,
in the course of a single dwell, the correlation is modified as a function of the
Doppler information.
