Sirf Technology, Inc.

Csr Technology Holdings Inc.

David Allan Tuck

Keith J Brodie

Mangesh M Chansarkar

Ardalan Heshmati

The present invention is related to position calculation and navigation systems, and more particularly, to a method and apparatus for making accuracy improvements to a GPS receiver's navigation solutions. According to a first aspect, selective cartography information from a map database accessed by a GPS receiver from a location-aiding device is integrated into the position calculations performed by the GPS receiver. According to another aspect, selective cartography information includes indices representing associated attributes of geographical objects, such as, a width-indicator index for a road segment.

Method and apparatus for geographically aiding navigation satellite system solution

A method for navigation processing in a satellite positioning system receiver is disclosed. A method in accordance with the present invention comprises separating the three SATPS satellites into a first pair and a second pair, constructing a primary solution and an alternate solution, wherein the primary solution and the alternate solution satisfy the measurement constraints, computing a Doppler difference estimate for the primary solution and a Doppler difference estimate for the alternate solution, computing Doppler difference residuals for the first pair and the second pair of SATPS satellites, and comparing the Doppler difference residuals for said primary and alternate solutions to determine a valid solution. Typically, the computing of a Doppler difference residuals comprises differencing a measured Doppler difference from an estimated Doppler difference for the first pair and the second pair of SATPS satellites. Typical determination of a valid solution comprises comparing the difference between the Doppler difference residuals to a predetermined number. Usually when the Doppler difference residuals exceed the predetermined number, the alternate solution is selected as the valid solution.

Navigation processing for a satellite positioning system receiver

The invention comprises a set of pseudolites deployed throughout an area of interest in which the GPS constellation visibility may be limited, such as in and around some high-rise buildings in an urban setting, and a database of these installed pseudolite locations with their PRN numbers indexed by cell-site. When the cellular telephone is in communication with a particular tower or transceiver, the PRN numbers of all local pseudolites are transmitted to the cellular telephone. If the cellular telephone has a position solution which has been transmitted to the cell tower, prepositioning information for a code search can be transmitted to the phone as well. The phone can then augment the phone's normal acquisition list with the pseudolites in the area and track the pseudolites to augment navigation capabilities in a harsh environment.

Network assisted pseudolite acquisition for enhanced GPS navigation

The invention comprises a set of pseudolites deployed throughout an area of interest in which the GPS constellation visibility may be limited, such as in and around some high-rise buildings in an urban setting, and a database of these installed pseudolite locations with their PRN numbers indexed by cell-site. When the cellular telephone is in communication with a particular tower or transceiver, the PRN numbers of all local psuedolites are transmitted to the cellular telephone. If the cellular telephone has a position solution which has been transmitted to the cell tower, prepositioning information for a code search can be transmitted to the phone as well. The phone can then augment the phone's normal acquisition list with the psuedolites in the area and track the pseudolites to augment navigation capabilities in a harsh environment.

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El Segundo, CA, United States of America

David Allan Tuck