A system is provided with a ranging transmitter and receiver pair or a transceiver pair. The system classifies a group of radio frequency (RF) channels between ranging transmitter and receiver pairs. In a first scenario, a ranging transmitter transmits at least three channels to an active reflecting receiver. A ranging receiver then receives reflected instances of the at least three transmitted channels from the active reflecting receiver. A processor of the system then determines a ranging measurement between the ranging transmitter and the active reflecting receiver based on measured phase changes and received signal strength and assigns a classification to the determined ranging measurement indicating a relative level of accuracy for the determined ranging measurement. The classification may be a general classification, a linearity classification, a multipath classification, or a combination classification that is based on both a linearity classification and a multipath classification.

A target detection apparatus includes a target detection means, a depth determination value calculation means, a crossing over determination means, an attention information setting means, a tracking means, a transfer determination value calculation means, and an attention information cancelling means. The depth determination value calculation means determines a depth determination value indicating the depth of a target. The crossing over determination means determines whether the target can be crossed over by the vehicle. The attention information setting means sets attention information indicating that the target needs to be paid attention. The tracking means determines a connection relationship between a current-cycle target and a previous-cycle target and cause the current-cycle target having a connection relationship, to adopt information relating to the previous-cycle target. The transfer determination value calculation means determines a transfer determination value, for each target. The attention information cancelling means cancels the setting of the attention information.

A method may include receiving radar data from a plurality of TX-RX pairs (TRPs); generating a plurality of first ellipses representing a first portion of the received radar data; determining a blocking likelihood at a point of intersection between the plurality of first ellipses; generating a new or additional ellipse representing a second portion of the received radar data; and updating, based on generating the new or additional ellipse, the blocking likelihood at the point of intersection between the first plurality of ellipses.

Radar equipped with a transmission antenna array and with a reception antenna array is provided, the measurement of the height h.sub.2 is obtained by estimating the frequency of at least one time-dependent amplitude modulation produced on the reception antenna array, the modulation generated by the interference of the signals received directly from the target and the signals received after reflection on the ground, on the basis of the signals transmitted by the transmission antenna array.

The invention relates to a method for object classification which comprises the following steps for providing an ellipti-cally or circularly polarized transmission signal which is transmitted to the object to be classified: generating a first radar image from the copolarly polarized reflection signal and generating a second radar image from the cross-polarized reflection signal and comparing the first radar image with the second radar image.

A system and method for locating radio-frequency identification tags within a predetermined area. The method can incorporate sub-threshold superposition response mapping techniques, alone, or in combination with other methods for locating radio-frequency identification tags such as but not limited to time differential on arrival (TDOA), frequency domain phase difference on arrival (FD-PDOA), and radio signal strength indication (RSSI). The system can include a plurality of antennas dispersed in a predefined area; one or more radio-frequency identification tags; a radio-frequency transceiver in communication with said antennas; a phase modulator coupled to the ra-dio-frequency transceiver; and a system controller in communication with said transceiver and said phase modulator. Calibration techniques can be employed to map con-structive interference zones for improved accuracy.

An interactive system includes a device configured to output a signal toward a surface such that the signal reflects off the surface at an angle and along a path of travel, and such that an object that interrupts the path of travel of the signal causes a return signal to travel in a reverse direction along the path of travel for receipt by the device. The interactive system also includes a control system communicatively coupled to the device. The control system is configured to receive data from the device, in which the data is associated with the receipt of the return signal by the device, and determine a position of the object relative to the device based on the data.

A method for activating a vehicle function, by an activation device including a transceiver to communicate with hands-free access equipment. The transceiver is equipped with a gyroscope and a magnetometer and two receiving antennas that have a coefficient of electromagnetic coupling between them that is below a threshold. The method includes the following steps for at least two consecutive footsteps: transmission of a signal comprising data of the gyroscope and the magnetometer of the hands-free equipment to the vehicle; comparison of the data with representative values of the gyroscope and the magnetometer of the transceiver; determination of a first direction of the user; determination of a second direction of the user based on an estimation of a first angle of arrival of the signal towards the transceiver; comparison of the first direction and the second direction; activation of the vehicle function on the basis of the result of the comparison.

Methods, apparatus and systems for detecting and monitoring vital signs in real time are disclosed. In one example, a system for monitoring a repeating motion in a venue is disclosed. The system comprises a transmitter, a receiver, and a repeating motion monitor. The transmitter is located at a first position in the venue and configured for transmitting a wireless signal through a wireless multipath channel impacted by the repeating motion of an object in the venue. The receiver is located at a second position in the venue and configured for: receiving the wireless signal through the wireless multipath channel impacted by the repeating motion of the object in the venue, and obtaining a time series of channel information (CI) of the wireless multipath channel based on the wireless signal. The repeating motion monitor is configured for: monitoring a periodic characteristics of the repeating motion of the object based on the time series of CI.

Methods, systems, and products determine electromagnetic reflective characteristics of ambient environments. A wireless communications device sends a cellular impulse and receives reflections of the cellular impulse. The cellular impulse and the reflections of the cellular impulse may be compared to determine the electromagnetic reflective characteristics of an ambient environment.