A position estimation device includes: a selector configured to select N wireless terminals and reselect N wireless terminals from M wireless terminals; a distance calculator configured to calculate distances among wireless terminals in a group consisting of a parent wireless terminal and the N wireless terminals based on information on power of radio signals of packets transmitted and received; a relative position calculator configured to calculate relative positions of the M wireless terminals based on the distances among the wireless terminals in the group for the N wireless terminals selected and reselected; and an absolute position converter configured to convert a relative position of a child wireless terminal into an absolute positon of the child wireless terminal based on the relative positions of the M wireless terminals and absolute positions of at least three of the M wireless terminals where the absolute positions are known.

Positioning systems and methods for estimating an altitude of a receiver. In some embodiments, pressure and temperature information from a network of sensors is received by the receiver, and the pressure and temperature information from the network of sensors is used along with pressure information measured at a position of the receiver to estimate the altitude of the receiver.

An exemplary radio-frequency (RF)-based navigation reference system uses one or more non-collocated and time-synchronized direction-finding transmitters to enable a client receiver to estimate its own 3-D position, velocity and time (PVT) using direction-finding (DF) waveforms obtained from said reference transmitters. At least one reference transmitter is sufficient for obtaining a 3-D PVT solution provided the client receiver is equipped with an accurate (low-drift) local clock such as a chip-scale atomic clock (CSAC). All other client receivers require at least two reference transmitters to estimate their 3-D PVT.

Methods and apparatus are disclosed for sharing, by a first User Equipment, interception-assistance information relating to an uplink signal transmitted by the first User Equipment. The interception-assistance information may be used to assist a second User Equipment to intercept the uplink signal and measure at least one characteristic of it. Calculation-assistance information may be used to assist in the calculation of a position or in time, based on the measured characteristic.

The present invention provides a BeiDou-based grid augmentation autonomous driving multi-level warning system comprising a Beidou Satellite Ground-based Augmentation system, user terminals and a Vehicles internet system, wherein the Beidou Satellite Ground-based Augmentation system comprises Beidou grid reference stations, a data processing system and a data broadcast system; the user terminal comprises an in-vehicle receiver and a calculating chips. The present invention can reduce the occurrence of traffic accidents and reduce the loss of life and property.

A software-defined receiver (SDR) using real long term evolution (LTE) signals may be used for navigation. The LTE SDR leverages the structure of the downlink LTE signal, and provides signal acquisition, navigation-relevant high-level system information extraction, and signal tracking. The LTE SDR also provides the ability to obtain a time-of-arrival (TOA) estimate from received LTE signals, which provides a navigation solution comparable to a GPS-only navigation solution.

An in-vehicle communication device includes a transmission controller configured to perform control so that a first signal is transmitted from outside and a predetermined second signal is transmitted from outside and inside, after the transmission of the first signal, and a determination unit configured to determine whether the terminal device is present outside or inside based on a first response signal that is transmitted from the terminal device after the transmission of the second signal. When the determination unit is unable to determine whether the terminal device is present outside or inside, the transmission controller is configured to perform control so that a third signal is transmitted from inside, and the determination unit is configured to determine whether the terminal device is present outside or inside based on a second response signal that is transmitted from the terminal device after the transmission of the third signal.

Systems and Methods for RF Emitter Location with automatic UAS array reconfiguration. The system includes at least a first emitter of electromagnet emissions. There is an array controller and, in some situations, at least one array follower. The controller(s) each have a receiver to receive signals from the first emitter. The controller calculates the location of the first emitter based upon communications with the first emitter and any array follower.

A mobile computing device includes: a tracking sensor; a rangefinder; and a controller configured to: based on data from the tracking sensor, determine a current pose of the mobile computing device in a facility coordinate system, the facility containing a target wireless transmitter at an installed position; receive a transmission from the target wireless transmitter, containing an identifier of the target wireless transmitter; receive, from the rangefinder, a range value indicating a distance between the current pose and the target wireless transmitter; correlate the identifier with the range value, based on a property of the transmission; generate a location defining the installed position in the facility coordinate system, based on the current pose and the range value; and store the generated location in association with the identifier.

A smart anchor-based position estimation method and apparatus are disclosed. The position estimation method, performed by a position estimation apparatus, includes: identifying one or more line-of-sight (LOS) anchors from among one or more anchors mounted in a vehicle; selecting reference anchors from among the one or more LOS anchors; and estimating a position of a tag based on a number of the reference anchors. The reference anchors are selected based on a rate of formation of an ultra-wideband (UWB) link to the tag and accuracy of the estimated position of the tag.