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 disclosed method for a locating system comprises transmitting, by at least two transmitters on each of at least one transmitter platform, at least one signal, where each of the signals transmitted from a different transmitter is modulated at a different oscillation frequency, and the distance between the transmitters on each of the transmitter platforms is known. The method further comprises receiving, by a detector(s) on each of a target platform(s), the signal(s). When the detector(s) receives the signal(s), the signal(s) is focused at a location on the detector(s). Also, the method comprises determining an angle the signal(s) is being transmitted to the detector(s) from the transmitters by using the location(s). Further, the method comprises determining a relative position of each of the transmitter platform(s) with respect to the target platform(s) by using the angle(s) and by using the distance between the transmitters on each of the transmitter platform(s).

A disclosed method for a locating system comprises transmitting, by at least two transmitters on each of at least one transmitter platform, at least one signal, where each of the signals transmitted from a different transmitter is modulated at a different oscillation frequency, and the distance between the transmitters on each of the transmitter platforms is known. The method further comprises receiving, by a detector(s) on each of a target platform(s), the signal(s). When the detector(s) receives the signal(s), the signal(s) is focused at a location on the detector(s). Also, the method comprises determining an angle the signal(s) is being transmitted to the detector(s) from the transmitters by using the location(s). Further, the method comprises determining a relative position of each of the transmitter platform(s) with respect to the target platform(s) by using the angle(s) and by using the distance between the transmitters on each of the transmitter platform(s).

An apparatus for indicating a direction of a radio transmission is described. The apparatus includes at least one vector detection device including two or more antennas and an attenuating material between at least one of the antennas and a source of a radio transmission. The attenuating material is arranged to vary an amount of attenuation with an angle of the source with respect to at least one of the antennas. The apparatus is configured to generate a signal indicating a direction of the radio transmission by comparing received signal strengths from the two or more antennas.

An apparatus for indicating a direction of a radio transmission is described. The apparatus includes at least one vector detection device including two or more antennas and an attenuating material between at least one of the antennas and a source of a radio transmission. The attenuating material is arranged to vary an amount of attenuation with an angle of the source with respect to at least one of the antennas. The apparatus is configured to generate a signal indicating a direction of the radio transmission by comparing received signal strengths from the two or more antennas.

A user terminal, vehicle, and controlling method of vehicle is provided. The vehicle includes a communication module configured to communicate with a user terminal and a controller configured to acquire a location of the user terminal, which corresponds to a search signal, when the search signal is received from the user terminal and to determine, based on sensor information of the user terminal, whether the acquired location of the user terminal is valid when the sensor information of the user terminal is received from the user terminal.

A location system includes multiple master nodes located at corners of a coverage area. At least two master nodes are located on one edge of the coverage area and receive signals from a slave node within the coverage area. The at least two master nodes calculate a distance to the slave node and a location of the slave node within the coverage area.

A location system includes multiple master nodes located at corners of a coverage area. At least two master nodes are located on one edge of the coverage area and receive signals from a slave node within the coverage area. The at least two master nodes calculate a distance to the slave node and a location of the slave node within the coverage area.

Systems and methods are provided that may be implemented to modify information of an audio data transmission based on one or more measured signal reception and/or transmission characteristics of a radio frequency (RF) signal data transmission that contains or otherwise conveys the audio data transmission. The modified audio data may then be acoustically reproduced in analog form as sound waves. Examples of signal reception characteristics of a RF signal data transmission that may be measured and used as a basis for modifying information of audio data of an audio data transmission include, but are not limited to, time Difference of Arrival (TDOA), Angle of Arrival (AoA), measured received signal strength, etc. Example signal transmission characteristics of a RF signal that may be measured and used as a basis for modifying information of audio data include, but are not limited to, Angle of Departure (AoD).

Systems and methods are provided that may be implemented to modify information of an audio data transmission based on one or more measured signal reception and/or transmission characteristics of a radio frequency (RF) signal data transmission that contains or otherwise conveys the audio data transmission. The modified audio data may then be acoustically reproduced in analog form as sound waves. Examples of signal reception characteristics of a RF signal data transmission that may be measured and used as a basis for modifying information of audio data of an audio data transmission include, but are not limited to, time Difference of Arrival (TDOA), Angle of Arrival (AoA), measured received signal strength, etc. Example signal transmission characteristics of a RF signal that may be measured and used as a basis for modifying information of audio data include, but are not limited to, Angle of Departure (AoD).