Abstract: A satellite positioning system receiver programmed to determine information for a satellite using ephemeris data (710), determine information for the same satellite using almanac data (722), which may have been previously stored on the receiver, to determine an error between the satellite information determined from the ephemeris data and the satellite information determined from the stored almanac data (730), and to update the stored almanac data based upon the error (734).

Abstract: GPS assistance message and data issue identifiers for transmission to GPS enabled mobile stations in cellular communications networks and methods therefore. The GPS data issue identifiers indicate whether GPS data, for example corresponding ephemeris and almanac data, stored at the mobile station requires updating. In the exemplary 3rd generation (W-CDMA/UMTS) architecture, the GPS assistance message is a System Information Block (SIB), and the GPS ephemeris data identifier and corresponding satellite identifier is encoded in a value tag included in a Master Information Block (MIB).

Abstract: An assisted global positioning satellite (Assisted GPS) system has a GPS reference network node (260) that collects GPS satellite broadcast messages and prepares separate GPS assistance messages to be modulated by a base transceiver station (BTS) (202) on a cellular carrier signal (201) and sent to single or multiple handset (204). In a first preferred embodiment, instead of the handset (204) receiving standard ephemeris and clock correction data elements in a GPS assistance message, a compressed GPS assistance message containing XYZ information contains a GPS satellite's coordinate position modified according to the satellite clock correction. In a second preferred embodiment, there is a first type of compressed GPS assistance message containing subframe 1, 2, 3 data of a GPS satellite broadcast message and a second type of compressed GPS assistance message containing subframe 4, 5 data of a GPS satellite broadcast message.

Abstract: A method in a satellite positioning system receiver, including acquiring (210) a set of satellite positioning system satellites, determining (220) satellite subset time based on over-determined position solutions for at least two different subsets of the satellites acquired, determining (230) satellite time from at least two satellite subset times, computing (250) a position solution based on the satellite time or a refined (240) satellite time.

Abstract: A satellite positioning system receiver having a battery, wherein the receiver is programmed to determine (310) whether the receiver is connected to a power supply other than its battery, to begin continuous reception (320) of satellite positioning system navigation data when the receiver is connected to a power supply other than its battery, and to store (330) the navigation data received in memory of the receiver.

Abstract: A satellite positioning system receiver programmed to operate synchronously with an expected time of arrival of information from at least one satellite of a satellite positioning system, and to receive the information from the at least one satellite when the receiver is operating during the expected time of arrival of the information. In one embodiment, the receiver operates synchronously with an expected arrival of specific subframe information from at least one satellite of a satellite positioning system, and receives the specific subframe information when the receiver is operating.

Abstract: A cellular network protocol that maintains the reliability of assisted GPS based positioning is taught. An Integrity Monitor (IM) informs mobile stations, their users, or networks of measurement quality and it warns them of failing and failed GPS satellites by isolating them from the effects of these failures. Whenever an unhealthy satellite is detected, its corresponding assistance data will be excluded for delivery or for position determination. In other words, there are two specific aspects to the Integrity Monitor (IM). For DGPS users, it predicts the reliability or quality of the DGPS corrections. For all users, it isolates the mobile position calculation from the effects of GPS satellite failures. The UDRE parameter, nominally output by a reference DGPS receiver, is used to communicate the DGPS quality information, and DGPS corrections are simply excluded for failed satellites.

Abstract: A method in a satellite positioning system (SPS) receiver 100 including acquiring a plurality of at least two SPS signals, estimating frequency error for each of the plurality of SPS signals, and compensating for the frequency error of each of the plurality of SPS signal based on the estimated frequency errors for all of the plurality of SPS signals.

Abstract: A method (500) and a mobile station (160) for determining a code phase are described herein. The mobile station (160) may generate a first auto correlation function (ACF) associated with correlation samples over a range of code phases corresponding to a line-of-sight signal. The mobile station (160) may generate a second ACF within the mobile station based on measured correlation samples over a range of code phases. The mobile station (160) may compare the first ACF to the second ACF to generate a code phase offset between the first and second ACFs. The mobile station (160) may adjust the first ACF to match the second ACF.

Abstract: A method for locating a satellite positioning system receiver, for example, a satellite positioning system enabled wireless communications device in cellular network, including obtaining a coarse position and/or a time estimate (210), and computing a satellite positioning system based position and/or time solution (240) that is constrained by uncertainty information associated with the coarse position and/or a time estimate. The uncertainty constraints may also be used to identify erroneous measurements used to compute the position solution.

Abstract: A method in a satellite positioning system receiver having stored almanac data including determining information for a satellite using ephemeris data (710), determining information for the same satellite using the stored almanac data (722), determining an error between the satellite information determined from the ephemeris data and the satellite information determined from the stored almanac data (730), and updating the stored almanac data based upon the error (734).

Abstract: A method for locating a satellite positioning system receiver, for example, a satellite positioning system enabled wireless communications device in cellular network, including obtaining a coarse position and/or a time estimate (210), and computing a satellite positioning system based position and/or time solution (240) that is constrained by uncertainty information associated with the coarse position and/or a time estimate. The uncertainty constraints may also be used to identify erroneous measurements used to compute the position solution.

Abstract: A method (500) and a mobile station (160) for determining a code phase are described herein. The mobile station (160) may generate a first auto correlation function (ACF) associated with correlation samples over a range of code phases corresponding to a line-of-sight signal. The mobile station (160) may generate a second ACF within the mobile station based on measured correlation samples over a range of code phases. The mobile station (160) may compare the first ACF to the second ACF to generate a code phase offset between the first and second ACFs. The mobile station (160) may adjust the first ACF to match the second ACF.

Abstract: Methods for determining the location of a satellite positioning system receiver by determining an estimated location of the receiver (200), transmitting the estimated location of the receiver to a network, determining a reference altitude of the receiver at the network based upon the estimated location of the receiver (210), and determining a new location of the receiver based upon the reference altitude of the receiver (220). In some embodiments, terrain slope is determined at the estimated location for use in updating the estimated location. In some embodiments, satellite information and weighting factors used to estimate receiver location along with other parameters are utilized to update the estimated location.

Abstract: A method (50) for correcting oscillator frequency error in GPS signal acquisition includes a first step (52) of receiving at least one broadcasted GPS signal. A next step (54) includes estimating a plurality of Doppler offsets. A next step (56) includes correlating the signal to produce a Doppler modulation for each of the plurality of Doppler estimates. A next step (58) includes calculating a magnitude separation of peak and null states of each modulation. A next step (60) includes searching the peak and null separation to finding the Doppler estimate producing the largest magnitude separation in peak and null states. The found Doppler estimate defines a frequency error estimate for the at least one broadcasted GPS signal, which will be common across all satellites.

Abstract: A method (50) for correcting oscillator frequency error in GPS signal acquisition includes a first step (52) of receiving at least one broadcasted GPS signal. A next step (54) includes estimating a plurality of Doppler offsets. A next step (56) includes correlating the signal to produce a Doppler modulation for each of the plurality of Doppler estimates. A next step (58) includes calculating a magnitude separation of peak and null states of each modulation. A next step (60) includes searching the peak and null separation to finding the Doppler estimate producing the largest magnitude separation in peak and null states. The found Doppler estimate defines a frequency error estimate for the at least one broadcasted GPS signal, which will be common across all satellites.

Abstract: The present invention solves the problems of the prior art by providing methods for compensating for temperature-dependent drift of bias in a vehicle heading sensor of a dead reckoning vehicle positioning system. Specifically, the invention uses a Kalman filter to generate a calibration curve for the rate of heading sensor bias drift with temperature change. The Kalman filter calculates coefficients for a model of heading sensor bias drift rate versus temperature at each point where the vehicle is stationary. The bias drift rate calibration curve is then used to estimate a heading sensor bias periodically while the vehicle is moving. The invention further provides a method for using an aging time for temperature sensor bias drift rate to force convergence of the error variance matrix of the Kalman filter. The invention further provides vehicle navigational systems that utilize the methods of the present invention.

Abstract: The present invention solves the problems of the prior art by providing methods for compensating for temperature-dependent drift of bias in a vehicle heading sensor of a dead reckoning vehicle positioning system. Specifically, the invention uses a Kalman filter to generate a calibration curve for the rate of heading sensor bias drift with temperature change. The Kalman filter calculates coefficients for a model of heading sensor bias drift rate versus temperature at each point where the vehicle is stationary. The bias drift rate calibration curve is then used to estimate a heading sensor bias periodically while the vehicle is moving. The invention further provides a method for using an aging time for temperature sensor bias drift rate to force convergence of the error variance matrix of the Kalman filter. The invention further provides vehicle navigational systems that utilize the methods of the present invention.

Abstract: A cellular network protocol that maintains the reliability of assisted GPS based positioning is taught. An Integrity Monitor (IM) informs mobile stations, their users, or networks of measurement quality and it warns them of failing and failed GPS satellites by isolating them from the effects of these failures. Whenever an unhealthy satellite is detected, its corresponding assistance data will be excluded for delivery or for position determination. In other words, there are two specific aspects to the Integrity Monitor (IM). For DGPS users, it predicts the reliability or quality of the DGPS corrections. For all users, it isolates the mobile position calculation from the effects of GPS satellite failures. The UDRE parameter, nominally output by a reference DGPS receiver, is used to communicate the DGPS quality information, and DGPS corrections are simply excluded for failed satellites.

Abstract: An assisted global positioning satellite (Assisted GPS) system has a GPS reference network node (260) that collects GPS satellite broadcast messages and prepares separate GPS assistance messages to be modulated by a base transceiver station (BTS) (202) on a cellular carrier signal (201) and sent to single or multiple handset (204). In a first preferred embodiment, instead of the handset (204) receiving standard ephemeris and clock correction data elements in a GPS assistance message, a compressed GPS assistance message containing XYZ information contains a GPS satellite's coordinate position modified according to the satellite clock correction. In a second preferred embodiment, there is a first type of compressed GPS assistance message containing subframe 1, 2, 3 data of a GPS satellite broadcast message and a second type of compressed GPS assistance message containing subframe 4, 5 data of a GPS satellite broadcast message.