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 ?. 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.

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 ?. 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.

Methods and apparatus for sensor selection for localization and tracking are provided. A method (300) performed at an access point (101, 101a, 101b, 101c, 901, 902, 903) comprises: determining, a detectability of the access point (101, 101a, 101b, 101c, 901, 902, 903) for localization for a target device (102), based on channel state information of a radio link between the target device (102) and the access point (101, 101a, 101b, 101c, 901, 902, 903) (302); and determining whether the access point (101, 101a, 101b, 101c, 901, 902, 903) is to be used for position estimation of the target device (102) or not based on the detectability (304). A localization server (103) may further eliminate access points (101, 101a, 101b, 101c, 901, 902, 903) at poor positions from position estimation, by using a predefined weighted-kernel approach.

Methods and apparatus for sensor selection for localization and tracking are provided. A method (300) performed at an access point (101, 101a, 101b, 101c, 901, 902, 903) comprises: determining, a detectability of the access point (101, 101a, 101b, 101c, 901, 902, 903) for localization for a target device (102), based on channel state information of a radio link between the target device (102) and the access point (101, 101a, 101b, 101c, 901, 902, 903) (302); and determining whether the access point (101, 101a, 101b, 101c, 901, 902, 903) is to be used for position estimation of the target device (102) or not based on the detectability (304). A localization server (103) may further eliminate access points (101, 101a, 101b, 101c, 901, 902, 903) at poor positions from position estimation, by using a predefined weighted-kernel approach.

A method and a system are provided for detecting manned and unmanned vehicles intruding into a restricted area, including: operating a first vehicle and measuring multiple frequencies of electromagnetic radiation emitted from the first vehicle; determining, from the multiple frequencies of emitted electromagnetic radiation, one or more identifying electromagnetic radiation characteristics; and configuring a radio receiver to detect the one or more identifying electromagnetic radiation characteristics emitted by a second vehicle at a distance of a detection range.

The present invention is an information processor including: a storage configured to store information related to an area in which a user moves around; a position calculator configured to calculate, based on a transmission signal of a communication device that moves together with the user, positions in the area of the communication device with the lapse of time; and a measuring unit configured to measure time during which each of virtual points continuously exists in a region with movement of the user, each of the virtual points being defined at a point of intersection between virtual lines that are arranged in grid in the area, the region centering at each position that is calculated by the position calculator, wherein a size of the region is set to contain at least two of the virtual points.

A method for identifying an interferer in a wireless network, the method comprising: providing at least two scanners configured to receive a wireless network signal and to determine the signal's angle of arrival; providing a controller configured to communicate with the scanners, wherein the controller comprises mapping data indicating the location of the scanners and a user interface; requesting at least one of the scanners to perform a scan of the wireless network channels to detect a highly utilized channel; requesting at least two of the scanners to detect the angle of arrival of the signal in the highly utilized channel to the particular scanner; determining a location of a source of the signal in the highly utilized channel based on the mapping data and at least two angles of arrival of the signal to particular scanners; and presenting the location of the source of the signal by user interface.

A method for identifying an interferer in a wireless network, the method comprising: providing at least two scanners configured to receive a wireless network signal and to determine the signal's angle of arrival; providing a controller configured to communicate with the scanners, wherein the controller comprises mapping data indicating the location of the scanners and a user interface; requesting at least one of the scanners to perform a scan of the wireless network channels to detect a highly utilized channel; requesting at least two of the scanners to detect the angle of arrival of the signal in the highly utilized channel to the particular scanner; determining a location of a source of the signal in the highly utilized channel based on the mapping data and at least two angles of arrival of the signal to particular scanners; and presenting the location of the source of the signal by user interface.

In order to provide a receiver capable of accurately determining a phase difference of I/Q signals, a receiver includes a section detector configured to detect a section between a rising and a falling of a phase based on the rising and the falling of the phase represented by I/Q signals generated based on an advertisement packet transmitted from a transmitter, and a section setting unit configured to identify, within the section between the rising and the falling of the phase, a period in which a first variation amount of the phase is equal to or less than a first predetermined amount, and use the identified period as a section for detecting the phase of the I/Q signals. The section detector detects the rising when a first phase is smaller than a last phase among a plurality of phases acquired by sampling the phases.

A system and method of tracking and classifying an athlete's stick techniques used during a sporting event are disclosed, which includes measuring detailed motions and position of at least one stick object being used in sports, producing relevant stick technique patterns and classifying those patterns in a relevant manner. Classified stick pattern data is used to improve the accuracy and clarity of sporting event metrics, the ability to quantify athlete's skill and the ability to develop athletes based on their game situation techniques. The method used allows for accurate, near real-time discovery of stick patterns during live sporting events without altering or impacting the game or an athlete's ability to perform.