Title:
MOBILE COMMUNICATION APPARATUS
Document Type and Number:
WIPO Patent Application WO2002088767
Kind Code:
A3
Abstract:
In a mobile unit housing a two-way communications subsystem and a satellite positioning system (SPS) receiver subsystem, the communications subsystem includes a training signal generator for generating a training signal mimicking a positioning signal transmitted by a remote SPS transmitter. The training signal is frequency-coupled to a reference frequency source contained within and used by the communications subsystem, which source is, itself, stabilised by means of communication with a remote station, e.g. a base station in a cellular telephone system. In a training sequence, the training signal is activated and coupled into the SPS receiver subsystem, and a replica signal generator for generating a carrier replica signal for position-fixing purposes is controlled so as to bring the carrier replica signal into alignment with the training signal. Information representative of the control setting of the replica signal generator corresponding to such alignment is stored. Subsequently in a searching sequence, the training signal is deactivated and the replica signal generator is set to a setting based on the stored information for acquisition and processing of positioning signals from remote SPS transmitters.
Inventors:
PRATT ANTHONY RICHARD (GB)
Application Number:
PCT/GB2002/001898
Publication Date:
March 20, 2003
Filing Date:
April 24, 2002
Export Citation:
Assignee:
PARTHUS UK LTD (GB)
PRATT ANTHONY RICHARD (GB)
PRATT ANTHONY RICHARD (GB)
International Classes:
G01S1/00; G01S19/23; (IPC1-7): G01S5/14; G01S1/02
Foreign References:
| US6041222A | 2000-03-21 | |||
| US6178195B1 | 2001-01-23 | |||
| US5440491A | 1995-08-08 | |||
| US5841396A | 1998-11-24 | |||
| US6133874A | 2000-10-17 | |||
| GB2307812A | 1997-06-04 |
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