Abstract: Method and apparatus for validating an initial position in a satellite positioning system using range-rate measurements is described. In one example, range-rate measurements are obtained at the remote receiver with respect to a plurality of satellites. Expected range-rates are computed with respect to the plurality of satellites using the initial position. Single differences are computed using the range-rate measurements. Expected single differences are computed using the expected range-rates. Single difference residuals are computed between the single differences and the expected single differences. The single difference residuals are compared to a threshold. The initial position may be deemed valid if the absolute value of each of the single difference residuals is less than or equal to the threshold. A valid initial position may be used to fix the pseudorange integers.

Abstract: A method and apparatus for maintaining integrity of long-term-orbit information used by a Global-Navigation-Satellite-System or other positioning receiver is described. The method comprises obtaining a predicted pseudorange from a first set of long-term-orbit information possessed by a positioning receiver; obtaining, at the positioning receiver from at least one satellite, a measured pseudorange; determining validity of the predicted pseudorange as a function of the predicted pseudorange and the measured pseudorange; and excluding from the long-term-orbit information at least a portion thereof when the validity of the predicted pseudorange is deemed invalid. Optionally, the method may comprise updating or otherwise supplementing the long-term-orbit information with other orbit information if the validity of the predicted pseudorange is deemed invalid.

Abstract: A method of correlating a digital communications signal is described. In an example, a window is defined equal to a portion of an epoch of the digital communication signal. The digital communication signal is then correlated across the window. A determination is made as to whether a correlation peak results from the correlating. Timing parameters are then established for receiving additional digital communication signals in response to presence of the correlation peak.

Abstract: A device is disclosed that is capable of determining its location using high-power with high accuracy, and using low-power with lower accuracy. By coordinating usage between the high power method and the low power, overall power consumption of the device can be significantly reduced without a significant reduction in accuracy. Such high accuracy may be achieved through the use of a GNSS unit, such a GPS receiver. In addition, the low-power alternative may be achieved using an accelerometer, together with software, hardware or firmware for extrapolating a speed based on the force measurements by the accelerometer. In this manner, the GPS receiver can be operated for only a fraction of overall use, primarily to provide adjustment data necessary to calibrate usage of the accelerometer.

Abstract: A method and apparatus for distribution and delivery of global positioning system (GPS) satellite telemetry data using a communication link between a central site and a mobile GPS receiver. The central site is coupled to a network of reference satellite receivers that send telemetry data from all satellites to the central site. The mobile GPS receiver uses the delivered telemetry data to aid its acquisition of the GPS satellite signal. The availability of the satellite telemetry data enhances the mobile receiver's signal reception sensitivity.

Abstract: A multi-standard GNSS receiver, handle different global navigation satellite systems (GNSSs), determines with respect to a current time instant, the earliest broadcast timing based on corresponding satellite broadcast cycles for satellites in the different GNSSs. The multi-standard GNSS receiver acquires fresh broadcast ephemeris at the determined earliest broadcast timing to determine its own first position. A search order is determined based on the corresponding satellite broadcast cycles and the current time instant. The multi-standard GNSS receiver may selectively utilize appropriate satellite receivers such as the GPS receiver and the GLONASS receiver to search for satellite signals based on the determined search order. Channels for different GNSSs are scanned to identify transmitting satellites based on the corresponding satellite broadcast cycles for ephemeris downloading. The satellite search is prioritized by comparing the current time instant with the corresponding satellite broadcast cycles.

Abstract: Embodiments of the present disclosure use shared oscillator for cellular communications and location detection in a communication device. The communications device estimates a frequency offset of one of its subsystems. The communications device determines a frequency offset that results from drifting of this shared oscillator, typically caused by aging and/or changes in temperature, voltage, humidity, pressure, and/or vibration to provide some examples, from the frequency offset this subsystem. The communications device provides various compensation parameters to its various subsystems to compensate for the frequency offset that results from drifting of the oscillator.

Abstract: A method and apparatus for computing position using a regional-terrain model is provided. The method includes obtaining from at least three satellites pseudorange measurements, computing a transitional position by using a default altitude with a large uncertainty, using this transitional position to obtain from a terrain model altitude information associated with a region, and computing an accurate three-dimensional position as a function of the pseudorange measurements and the altitude information. The region defines a boundary, and the boundary includes the transitional position.

Abstract: A method and apparatus for mitigating multipath effects in a satellite signal receiver is described. In one example, measured pseudoranges are obtained from the satellite signal receiver to a plurality of satellites. For each measured pseudorange: an expected pseudorange is derived from a sequential estimation filter in the satellite signal receiver. The measured pseudorange and the expected pseudorange are differenced to compute a pseudorange residual. The measured pseudorange is applied to the sequential estimation filter only if the pseudorange residual is within a window.

Abstract: Aspects of a method and system for extending the usability period of long term orbit (LTO) are provided. A GPS enabled handset may receive LTO data from an AGPS server via a wireless communication network such as 3GPP or WiMAX. The GPS enabled handset may be enabled to receive broadcast GPS signals. The GPS enabled handset may extract navigation information from the received broadcast GPS signals to be used to adjust the received LTO data. The usability period of the received LTO data may be extended, accordingly. A clock model and a satellite health model associated with the extracted navigation information may be used to update or replace the clock model and/or the satellite health model of the received LTO data, respectively. A navigation solution for the GPS enabled handset may be determined more accurately based on the adjusted LTO data.

Abstract: A GNSS receiver in a wake up state during a standby mode may acquire ephemeris from received GNSS signals such as GPS signals and/or GLONASS signals. When subsequently transitioning from the standby mode to a normal mode operating at a high frequency clock, the acquired ephemeris may be utilized to generate a navigation solution for the GNSS receiver. The GNSS receiver in the wake up state during the standby mode may be switched to operate at the high frequency clock in order to receive GNSS signals. The GNSS receiver may extract complete ephemeris from the received GNSS signals, and may subsequently transition from the wake up state to a sleep state during the standby mode to save power. Radio frequency front-end components of the GNSS receiver may only be turned on to receive the GNSS signals. The GNSS receiver may transition between the standby mode and the normal mode.

Abstract: A GNSS receiver in a wake up state during a standby mode may acquire ephemeris from received GNSS signals such as GPS signals and/or GLONASS signals. When subsequently transitioning from the standby mode to a normal mode operating at a high frequency clock, the acquired ephemeris may be utilized to generate a navigation solution for the GNSS receiver. The GNSS receiver in the wake up state during the standby mode may be switched to operate at the high frequency clock in order to receive GNSS signals. The GNSS receiver may extract complete ephemeris from the received GNSS signals, and may subsequently transition from the wake up state to a sleep state during the standby mode to save power. Radio frequency front-end components of the GNSS receiver may only be turned on to receive the GNSS signals. The GNSS receiver may transition between the standby mode and the normal mode.

Abstract: A method and apparatus for computing position using a regional-terrain model is provided. The method includes obtaining from at least three satellites pseudorange measurements, computing a transitional position by using a default altitude with a large uncertainty, using this transitional position to obtain from a terrain model altitude information associated with a region, and computing an accurate three-dimensional position as a function of the pseudorange measurements and the altitude information. The region defines a boundary, and the boundary includes the transitional position.

Abstract: A method and apparatus for locating position of a GPS device is described. In one example, a method for provisioning a mobile device with a model for determining a position of the mobile device in at least one geographic area is provided. The method includes obtaining an estimate of the position of the mobile device, forming one or more satellite orbit models from the estimate and a wide area model, and sending the at least one satellite orbit model to the mobile device. The wide area model is formed from measurements from a plurality of satellites of a Global Positioning System, and the measurements are obtained by a plurality of reference stations.

Abstract: Method and apparatus for processing satellite signals from a first satellite navigation system and a second satellite navigation system is described. In one example, at least one first pseudorange between a satellite signal receiver and at least one satellite of the first satellite navigation system is measured. At least one second pseudorange between the satellite signal receiver and at least one satellite of the second satellite navigation system is measured. A difference between a first time reference frame of the first satellite navigation system and a second time reference frame of the second satellite navigation system, is obtained.

Abstract: Method and apparatus for locating position of a remote receiver is described. In one example, long term satellite tracking data is obtained at a remote receiver. Satellite positioning system (SPS) satellites are detected. Pseudoranges are determined from the remote receiver to the detected SPS satellites. Position of the remote receiver is computed using the pseudoranges and the long term satellite tracking data. SPS satellites may be detected using at least one of acquisition assistance data computed using a previously computed position and a blind search. Use of long term satellite tracking data obviates the need for the remote receiver to decode ephemeris from the satellites. In addition, position of the remote receiver is computed without obtaining an initial position estimate from a server or network.

Abstract: Method and apparatus for processing satellite signals from a first satellite navigation system and a second satellite navigation system is described. In one example, at least one first pseudorange between a satellite signal receiver and at least one satellite of the first satellite navigation system is measured. At least one second pseudorange between the satellite signal receiver and at least one satellite of the second satellite navigation system is measured. A difference between a first time reference frame of the first satellite navigation system and a second time reference frame of the second satellite navigation system is obtained. The at least one first pseudorange and the at least one second pseudorange are combined using the difference in time references.

Abstract: A method and apparatus for background decoding of a broadcast satellite-navigation message to maintain integrity of long-term-orbit information used in a Global-Navigation-Satellite System or other positioning system is described. The method may include processing the long-term-orbit information associated with at least one satellite to obtain a first position of a receiver; obtaining at least one portion of broadcast ephemeris transmitted from the at least one satellite; and processing, as a substitute for at least one portion of the long-term-orbit information, the at least one portion of broadcast ephemeris to obtain a second position of the receiver.

Abstract: A Global navigation satellite-based systems (GNSS) enabled device, handling at least two of a plurality of sensors, collects GNSS measurements and navigation related non-GNSS sensor data. The collected navigation related non-GNSS sensor data is automatically formatted into a data format that is compatible with a format of the GNSS measurements. The formatted navigation related non-GNSS sensor data and the GNSS measurements are utilized by a single function to compute navigation information for the GNSS enabled device regardless of sensor configurations such as a cellular radio and/or a motion sensor. Measurement errors in the collected navigation related non-GNSS sensor data is estimated to determine measurement accuracy. The collected navigation related non-GNSS sensor data is selectively adopted, combined with the GNSS measurements, to compute navigation information by the single function based on the determined measurement accuracy.

Abstract: A GNSS enabled mobile device receives GNSS signals from visible GNSS satellites. Broadcast ephemeris is extracted from the received GNSS signals for generating ephemeris extension (future ephemeris) in the next several days for each of the visible GNSS satellites. The GNSS enabled mobile device uses the generated future ephemeris to determine a position fix even without fresh broadcast ephemeris completely received from the visible GNSS satellites. The generation of future ephemeris is scheduled according to the age of available ephemeris extensions and/or the time of visibility. Available ephemeris such as extracted broadcast ephemeris are integrated into an orbit model using the multi-step numerical integration methods and propagated to generate future ephemeris. The generated future ephemeris is reformatted into a desired orbit model and/or format of the GNSS enabled mobile device.