Systems and methods for a low-frequency radio navigation system are described. The system may include a transmitter comprising a base coded modulator configured to generate a base modulation and a data coded modulator configured to generate a data modulation; wherein the transmitter radiates a continuous, constant-power chirped-FM spread spectrum signal, comprising: the base modulation; and the data modulation, wherein the data modulation is orthogonal to the base modulation. The system may also include a receiver comprising a digital signal processor, wherein at least one matched filter coupled to the digital signal processor, the at least one matched filter configured to decode said base modulation and data-encoded modulation and provide a correlation function for received signals received from at least three geographically-spaced transmitters.

A receiver circuit is disclosed. The receiver circuit includes one or more receiver antennas configured to receive a plurality of RF signals transmitted from a transmitter circuit including one or more transmit antennas, an RF chain configured to generate a plurality of digitized samples of the received RF signals, and a controller configured to receive the digitized samples, to calculate a plurality of additional samples, and to calculate a measured angle of arrival or angle of departure (AoA or AoD) of the RF signals based on the digitized samples and the calculated additional samples.

The disclosure provides a method and a device for positioning in wireless communication. A first node transmits Q1 first-type radio signal(s) and transmits first information; wherein the Q1 first-type radio signal(s) is(are) transmitted by Q1 spatial parameter group(s) respectively; the first information includes a first Identifier (ID) and Q1 piece(s) of channel information, and the first information is used for indicating Q1 geographic position(s); the Q1 piece(s) of channel information is(are) based on a channel measurement(s) performed by a target node for the Q1 spatial parameter group(s) respectively, and the target node is identified by the first ID; and the Q1 spatial parameter group(s) cover(s) the Q1 geographic position(s) respectively. The disclosure can improve the precision of positioning and meanwhile keep a good compatibility with existing systems.

A mobile electronic device includes a wireless communications interface configured to receive, from a remote device, a sequence of remote device proximity indicators. The sequence of remote device proximity indicators indicate positions of the remote device. A mobile proximity detector of the mobile electronic device is configured to monitor a current position and a current velocity of the mobile electronic device; determine, from the sequence of remote device proximity indicators, a current remote device position and current remote device velocity; and determine, using at least the current remote device position and velocity, and the current position and the current velocity of the mobile electronic device, a likelihood of close contact between a user of the mobile electronic device and the remote device. A notification manager of the mobile electronic device is configured to notify the user of the likelihood of close contact.

A mobile electronic device includes a wireless communications interface configured to receive, from a remote device, a sequence of remote device proximity indicators. The sequence of remote device proximity indicators indicate positions of the remote device. A mobile proximity detector of the mobile electronic device is configured to monitor a current position and a current velocity of the mobile electronic device; determine, from the sequence of remote device proximity indicators, a current remote device position and current remote device velocity; and determine, using at least the current remote device position and velocity, and the current position and the current velocity of the mobile electronic device, a likelihood of close contact between a user of the mobile electronic device and the remote device. A notification manager of the mobile electronic device is configured to notify the user of the likelihood of close contact.

A method for user localization in a cellular network includes receiving, by a receiver unit, Orthogonal Time Frequency Space (OTFS) modulated Constant-Amplitude-Zero-Autocorrelation (CAZAC) sequences generated and transmitted in a Doppler-delay domain by a transmitter unit. The method further includes estimating, by the receiver unit, Doppler shift and/or relative speed between the transmitter unit and the receiver unit by filtering the received OTFS modulated CAZAC sequences.

Disclosed are various techniques for wireless positioning. In an aspect, a user equipment (UE) determines one or more angle-based measurements of one or more reference signal resources transmitted by or received at the UE on one or more antennas of the UE and reports, to a positioning entity, the one or more angle-based measurements, a beam pattern associated with the one or more reference signal resources, a type of the one or more antennas, locations of the one or more antennas on the UE, an orientation of the one or more antennas, or any combination thereof.

A method is provided for estimating at least one characteristic of a signal received by a receiver, the signal having been transmitted in succession by a plurality of antennas in successive time segments, each segment being dedicated to one separate antenna, the signal being modulated into the form of pulses according to ultra-wideband modulation. The method includes steps of: receiving and digitizing the signal, computing the product of multiplication of each symbol of the received signal by the complex conjugate of the corresponding transmitted symbol, for each segment and for each symbol of the signal received for this segment, estimating a phase error by means of a phase-locked loop applied to the product, for each segment, determining a reference phase by means of a linear regression applied to the phase errors estimated for all of the segments, determining, for at least one pair of antennas, a phase difference between the signals transmitted by the antennas of the pair, on the basis of the difference between the reference phases computed for the segments associated with the antennas.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a first network node may receive a signal. The first network node may transmit an angle of departure (AoD) report that indicates at least one predicted AoD associated with a dominant channel cluster, wherein the at least one predicted AoD is based at least in part on the signal. Numerous other aspects are described.

A method is disclosed that includes associating an identifying information indicative of an item to be tracked from a first device to a second device. The method also includes assigning a master/slave information indicative of a responsibility that the first device and/or the second device is in charge of tracking the item from the first device to the second device. The method further includes determining a position estimate indicative of a position of the item to be tracked based at least partially on the identifying information and the master/slave information. The first device is directly related to the item to be tracked, and the second device is not directly to the item to be tracked. An apparatus, a tangible computer-readable medium and a system are also disclosed.