Receiver, apparatus, and method of despreading GPS signals
First Claim
1. A method of despreading a target GPS spread spectrum signal comprising pseudorandom noise (PRN) code sequences and received by a GPS receiver, the method comprising the steps of:
- providing Doppler information relating to an estimate of a variation in Doppler shift as observed on the target signal by the GPS receiver and which is attributable to motion of a GPS satellite;
modifying the target signal as a function of the Doppler information; and
correlating the target signal as modified 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.
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Accused Products
Abstract
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.
31 Citations
20 Claims
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1. A method of despreading a target GPS spread spectrum signal comprising pseudorandom noise (PRN) code sequences and received by a GPS receiver, the method comprising the steps of:
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providing Doppler information relating to an estimate of a variation in Doppler shift as observed on the target signal by the GPS receiver and which is attributable to motion of a GPS satellite;
modifying the target signal as a function of the Doppler information; and
correlating the target signal as modified 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. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A GPS receiver able to despread a GPS spread spectrum signal received by the GPS receiver, comprising a processor which:
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provides Doppler information relating to an estimate of a variation in Doppler shift as observed on the target signal by the GPS receiver and which is attributable to motion of a GPS satellite;
modifies the target signal as a function of the Doppler information; and
correlates the target signal as modified 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. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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14. A mobile telephone comprising:
a GPS receiver able to despread a GPS spread spectrum signal received by the GPS receiver, the GPS receiver comprising a processor which;
provides Doppler information relating to an estimate of a variation in Doppler shift as observed on the target signal by the GPS receiver and which is attributable to motion of a GPS satellite;
modifies the target signal as a function of the Doppler information; and
correlates the target signal as modified 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. - View Dependent Claims (15, 16, 17, 18, 19, 20)
Specification