Abstract: Disclosed are methods and systems for improving the safety of an intersection. One or more sensor readings can be received. The one or more sensor readings can be compared to one or more thresholds. A signal can be provided to one or more lighting devices based on whether the one or more sensor readings satisfy the one or more thresholds.

Abstract: In a system facilitating the calibration of a map-point grid for an indoor location determination, the grid includes several map points, each having a radio frequency (RF) data fingerprint being associated therewith. At least one of: (i) RF signal data from several RF sources, (ii) a user specified location indication, and (ii) tracking data from a sensor, the tracking data indicating a user's movement relative to a base map point, are received. The map-point grid is updated based on, at least in part, at least one of (i) adjusted RF data, the received RF data being adjusted using systematic analysis thereof, (ii) the tracking data, and (iii) the location indication. A user's location may be determined based on the fingerprints associated with the map-point grid, and sensor data.

Abstract: In a system facilitating the calibration of a map-point grid for an indoor location determination, the grid includes several map points, each having a radio frequency (RF) data fingerprint being associated therewith. At least one of: (i) RF signal data from several RF sources, (ii) a user specified location indication, and (ii) tracking data from a sensor, the tracking data indicating a user's movement relative to a base map point, are received. The map-point grid is updated based on, at least in part, at least one of (i) adjusted RF data, the received RF data being adjusted using systematic analysis thereof, (ii) the tracking data, and (iii) the location indication. A user's location may be determined based on the fingerprints associated with the map-point grid, and sensor data.

Abstract: In a system facilitating the calibration of a map-point grid for an indoor location, the grid includes several map points, each having a radio frequency (RF) data fingerprint associated therewith. RF data are received from a device associated with a user, and a map point is identified or determined based on, at least in part, the received RF data. A reliability of a fingerprint to be associated with the map point is computed based on, at least in part, a comparison of a parameter associated with the map point with reference data associated with the indoor location such as topology of the location, and speed and orientation of the user. A fingerprint is associated with the first map point based on, at least in part, the first RF data and the computed reliability. The computation of the reliability may also be based on additional RF data and location determination based thereon and/or user feedback. An existing fingerprint may be adjusted based on the received RF data.

Abstract: Systems and methods are disclosed herein for determining a user's location within an indoor environment. In particular, the system receives a location request including a set of radio frequency signal data collected by a mobile device inside of an indoor environment. Using this data set, the system first selects a map from a plurality of maps stored in a map database. The system then processes the data to identify the user's location on the selected map. The system uses yield information associated with the received signals in determining the map that the user is on, the user's location on the map, or both the map and the user's location to filter out transient signals and identify those signals that are reliably indicative of the user's location.

Abstract: The disclosed subject matter relates to a method for determining a Dilution of Precision Metric (DOP) with less than four satellites in a hybrid positioning system. In some embodiments, the method includes determining an initial position estimate of a device using a non-satellite positioning system, obtaining satellite measurements from less than four satellites, wherein the measurements include each satellite's position with respect to the initial position estimate, constructing a geometry matrix corresponding to the measurements from the less than four satellites using each satellite's position and the initial position estimate, multiplying the geometry matrix by its transpose to construct an H matrix, determining an inverse of the H matrix, and determining the DOP based on a sum of the diagonal elements of the inverse H matrix. In some embodiments, the non-satellite positioning system is a WLAN positioning system.

Abstract: The disclosed subject matter relates to a method for determining the position of a device in a hybrid positioning system. The method includes determining an initial position estimate of a device using a non-satellite positioning system, obtaining satellite measurements from less than four satellites, wherein the measurements include each satellite's position with respect to the initial position estimate, determining a dilution of precision (DOP) based on the satellite measurements, if the DOP is small, refining the initial position estimate using the satellite measurements, and if the DOP is large, providing the initial estimate as a final position estimate for the device. In some embodiments, the non-satellite positioning system is a WLAN positioning system. In some embodiments, the method includes obtaining satellite measurements from two satellites or three satellites.

Abstract: The present disclosure relates to a method for determining the position of a WLAN positioning system (WPS) and satellite positioning system (SPS) enabled device. The method can include determining an initial WPS position of the device using WPS, calculating an error region around the initial WPS position of the device, dividing the error region into a plurality of points, obtaining satellite measurements from at least two satellites in view of the device, determining a variation in a receiver clock bias for each point within the error region based on the satellite measurements from at least two satellites, selecting the point with the lowest variation in the receiver clock bias, and determining whether or not to use the point with the lowest variation in receiver clock bias to refine the initial WPS position of the device.

Abstract: Embodiments of the present invention include circuits and methods for dividing signals. In one embodiment the present invention includes a divider circuit comprising at least one first divider input receiving an in-phase (I+) signal, at least one second divider input receiving a complement of the in-phase (I?) signal, at least one third divider input receiving a quadrature (Q+) signal, and at least one fourth divider input receiving a complement of the quadrature (Q?) signal. In one embodiment, the lock range of a divider is improved by providing a first bias current greater than a second bias current.

Abstract: Embodiments of the present invention include a frequency synthesizer comprising a first plurality of dividers receiving a first signal having a first frequency and generating a first plurality of divided signals and a frequency combination network including a plurality of mixers, the frequency combination network receiving one or more of the first plurality of divided signals and generating a plurality of synthesized signals having different frequencies. The frequency combination network may further include additional dividers and multiplexers for more flexibility in synthesizing different frequencies. In one embodiment, the frequency combination network is coupled to dividers in the feedback path of a phase locked loop. The present invention is particularly advantageous for synthesizing frequencies above one (1) gigahertz.

Abstract: Embodiments of the present invention include circuits and methods for dividing high frequency signals. In one embodiment the present invention includes a divider circuit comprising a differential circuit having first and second inputs to receive a first differential signal, a first frequency control input and first and second differential outputs, wherein the differential circuit has a first bias current. The divider circuit further includes a cross-coupled circuit having outputs coupled to the differential circuit outputs and a second frequency control input, wherein the cross-coupled circuit has a second bias current. Embodiments of the present invention may include circuits for controlling the relationship between bias currents and circuit parameters that vary with process or temperature or both.