In a distance detection method, a target apparatus receives a first transmit signal from a detection apparatus. The target apparatus generates a first echo signal by modulating some of reflected signals of the first transmit signal to cause a first Doppler shift between the first echo signal and the first transmit signal. The target apparatus emits the first echo signal to the detection apparatus, which derives its distance from the target apparatus based on the first echo signal.

Disclosed is a radar detection assistant apparatus for increasing detection accuracy when detecting an object using a radar detection device. The radar detection assistant apparatus includes a radar signal receiver for adjusting a radar candidate signal received through a reception antenna to a predetermined magnitude and filtering out a signal other than the radar candidate signal, a radar signal analyzer for receiving the radar candidate signal from the radar signal receiver and determining whether or not the radar candidate signal is a preset radar signal, a radar signal production controller for generating a control signal for an assistant apparatus production signal or an assistant apparatus reproduction signal on the basis of at least one of pieces of information on a type, a bandwidth, and a period of the radar candidate signal received from the radar signal analyzer, and a radar signal producer.

The present document provides a method by which first vehicle-to-X (V2X) user equipment (UE) for supporting distance measurement transmits a ranging response signal in a wireless communication system, the method comprising: receiving a ranging request signal from second V2X UE; and transmitting, to the second V2X UE, the ranging response signal as a response to the ranging request signal on the basis of distance measurement parameter information, wherein the distance measurement parameter information includes information on a cyclic prefix (CP) length used for the ranging response signal, and the CP length used for the ranging response signal is different from a CP length to be used in V2X data channel transmission.

Markers and related systems and methods are provided for localizing lesions within a patient's body, e.g., within a breast. The marker includes one or more photosensitive diodes for transforming light pulses striking the marker into electrical energy, one or more antennas, and a switch coupled to the photodiodes and antennas such that the light pulses cause the switch to open and close and modulate radar signals reflected by the marker back to a source of the signals. The antenna(s) may include one or more wire elements extending from a housing, one or more antenna elements printed on a substrate, or one or more chip antennas. Optionally, the marker may include a processor coupled to the photodiodes for identifying signals in the light pulses or one or more coatings or filters to allow selective activation of the marker.

A transmission apparatus for a wireless device, comprising: an antenna for receiving an original signal and for backscattering a modulated signal containing information from the wireless device; a variable impedance coupled to the antenna, the variable impedance having an impedance value; a delta-sigma modulator coupled to the variable impedance for modulating the impedance value, and thereby a backscattering coefficient for the antenna, in accordance with the information to generate the modulated signal; and, a decoder coupled to the delta-sigma modulator for generating the impedance value from the information.

A technique for transmitting data from a passive radio device (100) is described. As to a method aspect of the technique, an antenna (102) of the passive radio device (100) is exposed to an incident radio signal (502). A frequency domain representation of the incident radio signal (502) comprised at least one muted gap between active subcarriers within a bandwidth of the incident radio signal (502). The incident radio signal (502) is backscattered from the antenna by modulating an impedance of the antenna according to the data using at least two different modulation frequencies that differ by less than the bandwidth.

A radar system for an autonomous driving vehicle (ADV) is disclosed. The system includes a target that includes a number of target elements disposed in a predetermined configuration on the target to collectively represent a radar readable code. The system further includes a radar unit included in the ADV and configured to: transmit a first electromagnetic (EM) signal to the target within a driving environment, receive a second EM signal reflected by the target, compute a radar cross section (RCS) signature based on the received second EM signal, generate a corresponding communication message based on the computed RCS signature, and transmit radar data that includes the communication message, where the ADV is controlled based on the communication message.

A method, system and apparatus are provided for estimating characteristics of a wireless communication channel between at least two passive radio frequency (RF) nodes. Backscatter channel state information (BCSI) is measured during communication between the at least two passive RF nodes using the wireless communication channel. An RF node aggregates the measured BCSI and the aggregated BSCI is analyzed to detect at least one activity of a plurality of activities.

Apparatus comprising at least one movable reflective surface configured to reflect electromagnetic waves and at least one actuator coupled with the at least one movable reflective surface, wherein said at least one actuator is configured to at least temporarily drive a movement of said at least one reflective surface.

A monitoring radar and a monitoring and identification method therefor are provided. The monitoring radar may be a physiological information monitoring radar. The monitoring and identification method may be a physiological information monitoring and identification method. The physiological information monitoring radar processes at least one reflected radar signal to obtain a response characteristic and range information corresponding to each of a plurality of to-be-monitored objects and distinguishes the response characteristic of each of the to-be-monitored objects as identification information or physiological information. The physiological information monitoring radar then labels each piece of physiological information according to the range information and the identification information.