Technologies for tracking the location of mobile assets include a tracking device mounted to an asset and radio-frequency identification tags installed or attached to static structures. The radio-frequency identification tags include identification data stored thereon. The identification data is associated with the installed location of the corresponding radio-frequency identification tags. The tracking device includes one or more transceivers configured to energize or trigger the radio-frequency identification tags and receive the stored identification data when the tracking device and asset are in proximity to the tags. The current location of the mobile asset is determined based on the identification data received from the radio-frequency identification tags.

A tag measurement environment evaluation device includes a processor and a memory storing a program. The program is configured to, when executed by the processor, cause the processor to determine a moving tag evaluation value of each of a plurality of wireless tags based on a radio wave transmitted from each of the wireless tags and received by a tag reader configured to communicate with each of the wireless tags, and determine whether a measurement environment is suitable for a moving tag detection based on the moving tag evaluation values.

The present invention relates to a system SY for determining a position of an RF transponder circuit RTC respective an ultrasound emitter unit UEU. The RF transponder circuit RTC emits RF signals that are modulated based on received ultrasound signals that are emitted or reflected by the ultrasound emitter unit UEU. The position of the RF transponder circuit RTC respective the ultrasound emitter unit UEU is determined based on a time difference ΔT1 between the emission of an ultrasound signal by the ultrasound emitter unit UEU and the detection by the RF detector unit RFD of a corresponding modulation in the RF signal emitted or reflected by the RF transponder circuit (RTC).

A transceiver may wirelessly transmit a communication signal at a first frequency and a sensing signal at a second frequency. The communication signal may include a command that causes a backscatter node to modulate impedance of an antenna, and thereby modulate reflectivity of the backscatter node. The communication signal may also deliver wireless power to the backscatter node. While the impedance is being modulated in response to the command, the transceiver may transmit the sensing signal and measure wireless reflections. The power of the sensing signal may be much lower than that of the communication signal. The transceiver may frequency hop the sensing signal in a wide band of frequencies and take measurements at each frequency in the hopping. Based on the measurements, a computer may determine time-of-flight or phase of a reflected signal from the backscatter node and may estimate location of the backscatter node with sub-centimeter precision.

A system for using thin and energy-autonomous backscatter tags and corresponding sensing nodes may operate with 24 GHz backscatter reflectarray tags having low power consumption. A digital beam steering, frequency-modulated continuous wave (FMCW) radar may be used for detection, localization, identification and communications. The tags may include environmental sensors that are used to modulate backscatter waves for data communications directed to a reader or may digitally modulate the backscatter transmissions without sensor data for independent localization of each tag in a network.

An aircraft has a first antenna arrangement, a payload and a processing unit. The first antenna arrangement is designed to wirelessly receive electromagnetic signals. The processing unit is coupled to the first antenna arrangement, on the one hand, and to the payload, on the other hand. The processing unit is designed to modulate an electromagnetic signal received by the first antenna arrangement and thereby to generate a first modulated signal and to forward it to the payload. The payload is designed to use the first modulated signal as working signal. A radiofrequency power signal on an uplink is thus remodulated into a payload working signal, such that the payload working signal is able to be used directly by the payload without rectification into a DC voltage.

An apparatus includes a pavement marker configured to be mounted to a road at a lane line of a lane at known orientation with respect to the lane line; and an RF device carried by the raised pavement marker. The RF device is configured to transmit a directional RF navigation signal and it is positioned relative to the known orientation to transmit the signal across the lane in a direction that is substantially normal to the lane line.

A wireless communication node (500) and method therein for generating and transmitting a modulated radio frequency (RF) signal by means of backscattering are disclosed. The wireless communication node (500) comprises an antenna (510) configured to receive a illuminating RF signal, a switch (520) that has M states, a set of impedances (530) comprising Mimpedances (Z1, Z2 . . . ZM). The antenna (510) is coupled to the set of impedances (530) by the switch (520). The wireless communication node (500) further comprises a modulating value generator (540) configured to generate modulating values based on data to be transmitted and a frequency offset and a switch controller (550) configured to switch the state of the switch (520) based on the generated modulating values such that the antenna (510) is connected to a selected impedance among the M impedances. The received illuminating RF signal at the antenna (510) is modulated by the generated modulating values and reflected by the antenna (510) to generate and transmit the modulated RF signal. The switching rate is an integer multiple of the data rate, the integer is greater than 1 and the center frequency of the modulated RF signal has the frequency offset with respect to the center frequency of the received illuminating RF signal.

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.

There is described an interior positioning system for tracking spatial position of communication devices within a remote location. The interior positioning system generally has: a radio frequency network distributed through said remote location; beacons spaced-apart from one another throughout said remote location and powered by said radio frequency network, each beacon locally emitting a corresponding beacon identifier which when received by a nearby communication device is communicated over said radio frequency network by said communication device; and a tracking controller being communicatively coupled to said radio frequency network, said tracking controller stored thereon tracking data associating each of said beacon identifiers to respective spatial coordinates, and instructions that when executed perform the steps of: receiving said beacon identifier communicated over said radio frequency network by said communication device, and determining spatial coordinates of said communication device by cross referencing said received beacon identifier to said tracking data.