An apparatus for matching probe measurements to a path in a geographic location includes a receiver, a window manager, a location generator, a path calculator, and an output. The receiver is configured to receive a stream of probe measurements. The window manager is configured to fill a window with the measurements, to select an additional measurement from the stream, and to select an oldest measurement in the window. The location generator is configured to generate candidate locations for the measurements in the window and the additional measurement. The path calculator is configured to match the oldest measurement to a candidate location. The output is configured to output a path-matched probe measurement based on the oldest measurement and the candidate location matched to the oldest measurement.

Techniques are discussed herein for detecting anomalous signals such as spoofed satellite positioning system (SPS) signals and for the transmission of accurate location estimates between user equipments (UEs) when the SPS signals are not reliable. A UE determines an SPS derived location estimate and determines an associated confidence level. The confidence level is determined based on time or location derived from the SPS signals, e.g., relative to local time or non-SPS information, such as stored previous location estimates, non-SPS sensor information, and location information from other UEs. The UE transmits location information to other UEs that includes a selected location estimate, confidence level, and the source of the location estimate, e.g., where the SPS derived location estimate is selected if the confidence level is high and the non-SPS derived location estimate is selected if the confidence level is low.

Techniques are discussed herein for detecting anomalous signals such as spoofed satellite positioning system (SPS) signals and for the transmission of accurate location estimates between user equipments (UEs) when the SPS signals are not reliable. A UE determines an SPS derived location estimate and determines an associated confidence level. The confidence level is determined based on time or location derived from the SPS signals, e.g., relative to local time or non-SPS information, such as stored previous location estimates, non-SPS sensor information, and location information from other UEs. The UE transmits location information to other UEs that includes a selected location estimate, confidence level, and the source of the location estimate, e.g., where the SPS derived location estimate is selected if the confidence level is high and the non-SPS derived location estimate is selected if the confidence level is low.

Disclosed is reducing starting time for a GNSS receiver that has an imprecise initial starting location by requesting starting assistance from a CDN that caches predictive data including first data indicated predicted LOS visibility from the receiver to individual satellites, wherein the request includes the imprecise initial staring location, receiving, from the CDN, data that includes a first block of the predictive data for the imprecise initial staring location and further adjoining second blocks of predictive data for areas surrounding the imprecise staring location, determining, by the GNSS receiver, commonly available satellites that have visibility from locations in both the first block and the second block, and calculating a first starting position using weighted values for the satellites, the commonly available satellites having higher weighted value than satellites without visibility in both locations, whereby position uncertainty of the first starting position is reduced from the imprecise initial starting location.

A method of processing signal paths includes receiving an estimated location for a GNSS receiver in an environment. The method also includes generating a plurality of candidate positions about the estimated location where each candidate position corresponds to a possible actual location of the GNSS receiver. The method further includes, for each available satellite at each candidate position, modeling a plurality of candidate signal paths by ray-launching a raster map of geographical data. Here, the plurality of candidate signal paths includes one or more reflected signal paths. At each candidate position, the method also includes comparing, the plurality of candidate signal paths modeled for each available satellite at the respective candidate position to measured GNSS signal data from the GNSS receiver and generating a likelihood that the respective candidate position includes the actual location of the GNSS receiver based on the comparison.

A method of processing signal paths includes receiving an estimated location for a GNSS receiver in an environment. The method also includes generating a plurality of candidate positions about the estimated location where each candidate position corresponds to a possible actual location of the GNSS receiver. The method further includes, for each available satellite at each candidate position, modeling a plurality of candidate signal paths by ray-launching a raster map of geographical data. Here, the plurality of candidate signal paths includes one or more reflected signal paths. At each candidate position, the method also includes comparing, the plurality of candidate signal paths modeled for each available satellite at the respective candidate position to measured GNSS signal data from the GNSS receiver and generating a likelihood that the respective candidate position includes the actual location of the GNSS receiver based on the comparison.

Techniques for enhanced Global Navigation Satellite Systems (GNSS) position determination can include capturing an image, from a camera, of obstructions near a mobile device. Orientation information regarding the camera can is used to determine where, in the image, the horizon is situated, and which portions of the sky are blocked by the obstructions from the perspective of the mobile device. Information regarding the location of satellites in the sky is obtained, based on an estimated position of the mobile device. Obstructed satellites can then be identified by comparing the location of the satellites with the obstructed portions of the sky. In a GNSS position determination, information received from the obstructed satellites can then be disregarded or de-weighted accordingly. In some embodiments, the information regarding the blocked portions of the sky can be sent to a server and/or shared with other nearby mobile devices.

Techniques for enhanced Global Navigation Satellite Systems (GNSS) position determination can include capturing an image, from a camera, of obstructions near a mobile device. Orientation information regarding the camera can is used to determine where, in the image, the horizon is situated, and which portions of the sky are blocked by the obstructions from the perspective of the mobile device. Information regarding the location of satellites in the sky is obtained, based on an estimated position of the mobile device. Obstructed satellites can then be identified by comparing the location of the satellites with the obstructed portions of the sky. In a GNSS position determination, information received from the obstructed satellites can then be disregarded or de-weighted accordingly. In some embodiments, the information regarding the blocked portions of the sky can be sent to a server and/or shared with other nearby mobile devices.

According to certain embodiments, a method performed by a wireless device comprises receiving Assisted-Global Navigation Satellite System (A-GNSS) information in system information broadcast by a network, receiving signals from a set of GNSS satellites (the set of GNSS satellites comprises at least three GNSS satellites), and determining a location of the wireless device using the A-GNSS information and information received in the signals from the set of GNSS satellites. The method further comprises determining Doppler time and frequency offsets compared to a network satellite. The Doppler time and frequency offsets are determined based on the location of the wireless device. The method further comprises initiating a connection process with the network satellite by transmitting a random access signal with pre-compensated time and frequency, the pre-compensated time and frequency based on the determined Doppler time and frequency offsets.

A method includes, when a preset condition is satisfied, obtaining, by a mobile terminal, base station information of neighboring cells of a serving cell in which the mobile terminal is currently located; obtaining, by the mobile terminal, assisted global navigation satellite system (AGNSS) assistant data according to the base station information of the neighboring cells, and performing, by the mobile terminal, positioning according to the AGNSS assistant data.