A system for providing smart road infrastructure for the purpose of vehicle safety and autonomous driving, comprising a plurality of road units, which are located along the borders of each traffic lane and equally spaced from each other, where each road unit includes a read/write passive RF tag; antenna for communicating with a plurality of transceivers, each of which is installed on each vehicle that travels along a traffic lane of said road, in response to signals transmitted from said transceivers; a memory for temporarily storing data regarding each vehicle traveling along said lane. Each car unit comprises a reader for interrogating said tags. The reader includes a first transceiver that is installed on the left front of said vehicle and a second transceiver that is installed on the right front of said vehicle; a processor being in bidirectional data communication with said transceivers and with the vehicle inherent control systems, for processing data received from said tags and calculating speed and location of said vehicle with respect to the borders of said lane and to other neighboring vehicles traveling in said lane and adjacent lanes, to implement vehicle safety operations such as Lane Departure Warning, Forward Collision Warning, Lane Keeping Assist, Lane Centering, Side Collision Warning. Alerting the driver (visually and/or audibly) regarding potential problems and/or taking over control of the vehicle (ADAS 1-5). The system can provide Connected Vehicles with accurate (ubiquitous and instantaneous) location data with lane-level resolution. The proposed smart infrastructure may complement car sensors and/or connected vehicles, so as to implement a combination that yield the most relabel and cost-effective autonomous driving system.

For a measurement period, signal strengths, device identifiers and access point identifiers are received from a plurality of access points. A record for the measurement period is stored in random access memory with the record being associated with a single device identifier and containing access point identifiers associated with signal strengths received for the measurement period. The location of a device is determined for the measurement period by retrieving spatial coordinates of a corresponding access point for each access point identifier in the record for the measurement period and setting the location of the device for the measurement period to the average of the retrieved spatial coordinates.

An RFID system includes multiple antennas and uses amplitude and phase information of the RFID signals received by each antenna to determine the position of RFID tags in the vicinity. More than one antenna can receive the RFID signals during a single read cycle, enabling the RFID system to operate more quickly than a system that energizes antennas separately.

A harmonic radar apparatus includes a transmitter configured to transmit a plurality of fundamental frequencies towards a scene. A further aspect of the harmonic radar apparatus includes a receiver configured to receive a reflected signal from the scene, the reflected signal being modulated based on the scene, and a re-radiated signal from a tag, the re-radiated signal being at a harmonic frequency of at least one of the plurality of fundamental frequencies transmitted by the transmitter.

This document generally relates to use of intelligent reflecting devices for positioning in wireless communication systems, which may increase the coverage for a wireless access node or base station. During a positioning session, an intelligent reflecting device may reflect a signal to a receiving node. An identity of the intelligent reflecting device may be determined, and a position of the receiving node may be determined based on the identity of the intelligent reflecting device.

The invention provides a target tag (10) for object tracking, wherein the target tag (10) is configured to detect listener beacon signals emitted by a plurality of listener nodes (110), wherein the target tag (10) has access to transmission power-related data and receiver sensitivity-related data of the plurality of listener nodes (110), and wherein in a tag operational mode the target tag (10) is configured to: detect the listener beacon signals and to determine related listener beacon signal strengths; determine a tag transmission power based on the related listener beacon signal strengths, the transmission power-related data, the receiver sensitivity-related data, and a predetermined goal number of reached listener nodes; and emit the target beacon signal at the tag transmission power.

The method of performing a positioning of a first apparatus by the first apparatus, transmitting a first signal to a second apparatus through at least one antenna; receiving a second signal from the second apparatus through each of the at least one antenna, wherein the second signal includes a bit related with a tag identifier(ID) of the second apparatus; obtaining the tag ID of the second apparatus, which is related with absolute location information of the second apparatus, based on the bit; and performing the positioning of the first apparatus, based on the first signal, the second signal, and the tag ID of the second apparatus.

A method includes transmitting, by a radiofrequency identification (RFID) reader device, a first electromagnetic radiation at a first polarization to a scan area and second electromagnetic radiation at a second polarization to the scan area. Re-radiated first electromagnetic radiation is received from an RFID tag located in the scan area at the first polarization. Re-radiated second electromagnetic radiation is received from the RFID tag at the second polarization. A radar image is generated based on the first and second re-radiated electromagnetic radiation. One or more items of information encoded in one or more microstructure elements located on the RFID tag are decoded based on the generated radar image. An RFID reader device and an RFID system are also disclosed.

For a measurement period, signal strengths, device identifiers and access point identifiers are received from a plurality of access points. A record for the measurement period is stored in random access memory with the record being associated with a single device identifier and containing access point identifiers associated with signal strengths received for the measurement period. The location of a device is determined for the measurement period by retrieving spatial coordinates of a corresponding access point for each access point identifier in the record for the measurement period and setting the location of the device for the measurement period to the average of the retrieved spatial coordinates.

A radio-frequency method for range finding includes modulating a reference signal having an intermediate frequency to a downlink signal having a carrier frequency using a clock signal. The downlink signal is transmitted to a tag using a transceiver. An uplink signal backscattered front the tag is received and demodulated using the clock signal. The uplink signal has a frequency that is a harmonic of the carrier frequency. A distance between the tag and the transceiver is calculated based on a phase of the demodulated uplink signal. A system for range finding includes a transceiver and a processor. The transceiver modulates a reference signal to downlink signal and transmits the downlink signal. The transceiver receives and demodulates an uplink signal. The processor is configured to receive the demodulated uplink signal and calculate a distance between the tag and the transceiver using a phase of the demodulated uplink signal.