Embodiments of the disclosed technology relate to improvements in location estimation and prediction for mobile devices while preserving energy. The use of classifiers is provided which preserves energy usage of the mobile device while providing contextually aware information for various stages. The use of a motion classifier and ranging in the context of access devices, the use of directional motion classifiers to reduce the latency in detection that a mobile device has entered a geofence area, and methods of improving location estimates and increasing geofence boundaries to prevent false exits from a geofenced area are disclosed.

A method for operating an ultra-wideband (UWB) device includes detecting the UWB device entering an access-controlled area that includes a gate configured to perform a UWB communication, retrieving an access token from an application server of the access-controlled area through a wireless communication other than the UWB communication prior to the UWB device entering a predetermined range of the gate, and transmitting the access token to the gate through the UWB communication after the UWB device entering the predetermined range of the gate.

A method for operating an ultra-wideband (UWB) device includes detecting the UWB device entering an access-controlled area that includes a gate configured to perform a UWB communication, retrieving an access token from an application server of the access-controlled area through a wireless communication other than the UWB communication prior to the UWB device entering a predetermined range of the gate, and transmitting the access token to the gate through the UWB communication after the UWB device entering the predetermined range of the gate.

A device includes an antenna controller configured to direct a beam to track a first satellite that follows an orbit having a transit arranged to intersect a transit of one or more other satellites to form a closed loop. The antenna controller is also configured to switch a tracking target of the beam from the first satellite to a second satellite of the one or more other satellites when the first satellite and the second satellite are at a first intersection of the transits that form the closed loop.

An electronic device wirelessly communicates with a terminal device by a wireless communicator, and includes a direction information acquisition unit and a processor. The direction information acquisition unit acquires, based on a beacon signal received by the wireless communicator from the terminal device, direction information related to a direction of the terminal device with respect to a reference position of the electronic device. The processor performs wireless connection of wirelessly connecting to the terminal device when the processor determines that, based on the direction information, the terminal device is positioned in a predetermined direction range.

An electronic device wirelessly communicates with a terminal device by a wireless communicator, and includes a direction information acquisition unit and a processor. The direction information acquisition unit acquires, based on a beacon signal received by the wireless communicator from the terminal device, direction information related to a direction of the terminal device with respect to a reference position of the electronic device. The processor performs wireless connection of wirelessly connecting to the terminal device when the processor determines that, based on the direction information, the terminal device is positioned in a predetermined direction range.

Aspects of the disclosure are directed to direction finding to a target device via one or more assisting devices. In an aspect, assisting device(s) (e.g., helper or cooperative devices) may provide assistance to a user equipment (UE) that is attempting to perform a direction finding operation to ascertain a direction from the UE to the target device. In an aspect, a single assisting device at a single location may be utilized in conjunction with the UE at multiple locations. In another aspect, multiple assisting devices may be utilized in conjunction with the UE at a single location. In a further aspect, a single assisting device at multiple locations may be utilized in conjunction with the UE at multiple locations. Such aspects may provide various technical advantages, such as improved direction finding accuracy and/or reduced direction finding latency.

A system is disclosed. The system may include a receiver or transmitter node. The receiver or transmitter node may include a communications interface with an antenna element and a controller. The controller may include one or more processors and have information of own node velocity and own node orientation relative to a common reference frame. The receiver or transmitter node may be time synchronized to apply Doppler corrections to signals, the Doppler corrections associated with the receiver or transmitter node's own motions relative to the common reference frame, the Doppler corrections applied using Doppler null steering along Null directions. The receiver node may comprise a correlator configured to process the signals which are based on the Doppler null steering.

Disclosed in the present invention is a method for estimating a direction of arrival of a sub-array partition type L-shaped coprime array based on fourth-order sampling covariance tensor denoising. The implementation steps are as follows: constructing an L-shaped coprime array partitioned with linear sub-arrays; modeling a receiving signal of the L-shaped coprime array and deriving a second-order cross-correlation matrix thereof; deriving a fourth-order covariance tensor based on the cross-correlation matrix; realizing fourth-order sampling covariance tensor denoising based on kernel tensor thresholding; deriving a fourth-order virtual domain signal based on denoised sampling covariance tensor; constructing a denoised structured virtual domain tensor; obtaining a direction of arrival estimation result by decomposing the structured virtual domain tensor. The present invention makes full use of the statistical distribution characteristics of the high-order tensor of the constructed sub-array partition type L-shaped coprime array, realizes high-precision two-dimensional direction of arrival estimation through denoised virtual domain tensor signal processing, and can be used for target positioning.

Provided are a direction of arrival (DOA) estimation method and system for a sparse array based on Vandermonde decomposition reconstruction, relating to the technical field of array signal processing. The method includes: constructing a covariance matrix completion optimization model based on sparse array signals and uniform linear array signals, and performing Vandermonde decomposition by using characteristics of a uniform linear array; introducing a nuclear norm to optimize a rank function in the model, and updating the covariance matrix completion optimization model; and introducing an auxiliary variable to transform the model into a solvable optimization problem, and solving the problem by an alternating direction multiplier method to obtain an optimal estimation value. The DOA is estimated using a root multiple signal classification algorithm.