A communication device comprising: a plurality of wireless communication units configured to perform wireless communication with another communication device; and a control unit configured to estimate positional information indicating a position at which the other communication device is located based on at least one distance measurement value indicating a distance between the other communication device and at least one wireless communication unit and obtained through the wireless communication of each of the plurality of wireless communication units, wherein the control unit corrects first positional information among a plurality of pieces of positional information estimated at different times based on second positional information different from the first positional information among the plurality of pieces of positional information.

A method for estimating the pressure measurement bias of a barometric sensor in a wireless terminal. A location engine using the method generates an enhanced estimate of the measurement bias. The location engine generates the enhanced estimate based in part on relatively coarse estimates of the elevation of the wireless terminal. Each coarse estimate of elevation is often generated from noisy measurements, such as measurements of signals transmitted by Global Positioning System (GPS) satellites, and has an associated uncertainty. The location engine accounts for the uncertainty in these estimates of elevation by applying an optimal estimation technique, such as Kalman filtering, and by compensating for environment-related effects. Compensating includes filtering across a plurality of lateral locations and imposing a lower bound of bias uncertainty at the lateral locations. Once the location engine generates the enhanced estimate of measurement bias, it can generate improved estimates of elevation of the wireless terminal.

A tracking system uses a mobile reader or scanner that scans, for example through a barcode reader, a passive tag reader, a probe, input, camera, or an active RF tag communication reader, and records item (asset or inventory) data. After being recorded, this item data and other relevant data is sent by radio transmission to a receiver network in the tracking system. The receiver network has at least two receivers (or at least two receiver antennae). The scanner location data, calculated by comparing the signal information at each receiver antenna receiving the radio transmission, is then used to register and record the location data of the scanned item.

A global resource locator (GRL) device can be used to track a physical asset. The GRL device can include a miniature atomic clock (MAC) and a processor communicatively coupled to the MAC. The processor can be configured to calculate a first location of the GRL device at a first time based on the MAC and determine that the first location is outside of a particular geofence. The processor can be configured to calculate a second location of the GRL device at a second time based on the MAC and determine that the second location is within the particular geofence. The processor can be configured to generate an event indicating the GRL device has crossed a border into the particular geofence based on the second location being inside of the particular geofence.

Method and apparatus are disclosed for preventing damage to an object within a charging field of a wireless vehicle battery charger. An example vehicle includes a wireless vehicle battery charger having a charging field, a plurality of Bluetooth antennas, and a processor. The processor is configured to identify a location of an object using one or more of the plurality of Bluetooth antennas, and, responsive to determining that the object is within the charging field, disable the wireless vehicle battery charger.

An RF position tracking system for wirelessly tracking the three-dimensional position of a tracked object. The tracked object has at least one mobile antenna and at least one inertial sensor. The system uses a plurality of base antennas which communicate with the mobile antenna using radio signals. The tracked object also incorporates the inertial sensor to improve position stability by allowing the system to compare position data from radio signals to data provided by the inertial sensor.

A radio frequency identification (RFID) system includes an array of antennas to distinguish line-of-sight (LOS) paths from non-line-of-sight (NLOS) paths. The distance between adjacent antennas in the array of antennas is less than half the wavelength of the radio frequency (RF) signal of the system. Each antenna in the antenna array is also digitally controlled to change relative phase difference among the antennas, thereby allowing digital steering of the array of antennas across angles of arrival (AOAs) between 0 and π. The digital steering generates a plot of signal amplitudes as a function of AOAs. LOS paths are distinguished from NLOS paths based on the shapes (e.g., depth, gradient, etc.) of local extremes (e.g., maxima or minima) in the plot.

The technology provides for a pair of earbuds. For instance, a first earbud may include a first antenna, and a second earbud may include a second antenna. The pair of earbuds may further include one or more processors configured to receive, from the first antenna, a first signal from a beacon, and receive, from the second antenna, a second signal from the beacon. Based on the first signal and the second signal, the one or more processors may determine at least one signal strength. The one or more processors may determine a position of the user relative to the beacon based on the at least one signal strength.

Provided is a face-to-face situation determination system in which a first beacon, which is a beacon carried by a first user, transmits a first signal including information identifying the first beacon. A second beacon, which is a beacon carried by a second user, upon receiving the first signal from the first beacon, transmits, toward a control device, a second signal including information identifying the first beacon, a first signal reception intensity, and information identifying the second beacon. The control device receives the second signal and, on the basis of the first signal reception strength included in the second signal, determines that the first user and the second user are facing each other if the first signal reception strength is greater than or equal to a first threshold value for a predetermined period or longer, and determines that the first user and the second user are facing one direction.

The present disclosure is to perform beamforming corresponding to the influence of a dynamic environment in which a user moves. The present disclosure relates to a beamforming prediction device that includes: a storage unit that stores a dictionary D obtained by learning fingerprints based on trajectories, and a fingerprint database based on trajectories; a trajectory prediction unit that calculates a trajectory of a mobile terminal, using location information about the mobile terminal; a fingerprint estimation unit that applies the trajectory of the mobile terminal to an input of the dictionary D, and calculates the sparse coefficient X corresponding to the trajectory of the mobile terminal; and a beamforming calculation unit that calculates beamforming of the mobile terminal, using the sparse coefficient X calculated by the fingerprint estimation unit and the fingerprint database.