A method of ranging between a first and a second radio signal transceiver comprises calculating a preliminary estimate of a value proportional to a one-way frequency domain channel response, for a frequency of a plurality of frequencies and for each of a first antenna combination and a second antenna combination of a plurality of antenna combinations; calculating a comparison value for the preliminary estimate, for the frequency and for each of the first antenna combination and the second antenna combination; determining, for the frequency and the first antenna combination, a corrected estimate of the value proportional to the one-way frequency domain channel response based on the preliminary estimate and the comparison value, for the first antenna combination and the second antenna combination; and performing a ranging calculation between the first and the second radio signal transceiver based on a plurality of such corrected estimates.

Disclosed are techniques for wireless sensing. In an aspect, a user equipment (UE) measures at least a line-of-sight (LOS) path and a non-line-of-sight (NLOS) path of a first downlink positioning reference signal (DL-PRS) from a first transmission-reception point (TRP), measures at least an LOS path and an NLOS path of a second DL-PRS from a second TRP, measures at least an LOS path and an NLOS path of a third DL-PRS from a third TRP, and enables a location of a non-participating target object to be determined based, at least in part, on reference signal time difference (RSTD) measurements between a time of arrival (ToA) of the LOS path of the first DL-PRS and the ToAs of the NLOS paths of the first, second, and third DL-PRS. In an aspect, the non-participating target object does not participate in determining its own location.

Systems and methods for inertial navigation aided by signals of opportunity (SOOP). One system includes a network operations center (NOC), a reference station, and mobile user equipment. Another system includes a NOC and user equipment without a reference station. In the latter system, the NOC comprises an antenna, a NOC receiver that generates SOOP data derived from SOOP, a computer system that generates SOOP source location/ephemeris data and inter-source clock bias data based on SOOP data generated by the NOC receiver, and a communication device to broadcast the data. The user equipment comprises an antenna, a navigation receiver that generates SOOP data derived from SOOP detected by the antenna of the user equipment, and a navigation computer system that calculates a navigation solution, including a SOOP-derived estimated position of the user equipment, based on SOOP source location/ephemeris data and inter-source clock bias data broadcasted by the NOC and SOOP data generated by the navigation receiver.

A system is disclosed for exploiting a transmitted signal from an aircraft to determine characteristics of any of the aircraft's motion or meteorological conditions in which the aircraft is moving. The system includes a plurality of platforms for detecting Doppler shift information of the transmitted signal at each of the plurality of platforms, and a processing system for determining characteristics of any of the aircraft's motion or meteorological conditions in which the aircraft is moving.

System and device configurations, and processes are provided for determining position based on low Earth orbit (LEO) satellite signals. Frameworks described herein can include performing Doppler frequency measurement for received quadrature phase shift keying (QPSK) signals. The framework may include channel tracking operations to determine Doppler shift measurements, a navigation filter operation to determine clock drift based on each Doppler shift measurement from each channel tracking loop, and determining position of a device based on LEO satellite signal sources. Frameworks described herein are also provided for carrier phase differential (CD)—low Earth orbit (LEO) (CD-LEO) measurements that may utilize a base and a rover without requiring prior knowledge of rover position. Embodiments can also cancel effects of ionospheric and tropospheric delays on the carrier phase and CD-LEO measurements.

First information corresponding to a radio signal received at a first sensing device from a candidate location is obtained. Second information corresponding to a radio signal received at a second sensing device from the candidate location is obtained. A first relationship between the first sensing device and the candidate location and a second relationship between the second sensing device and the candidate location are determined. A first inverse and a second inverse of respectively the first and second relationships are obtained. A first estimate of the radio signal at the first sensing device is determined from the first information and the first inverse. A second estimate of the radio signal at the second sensing device is determined from the second information and the second inverse. Energy emitted from the candidate location is measured based on the first estimate and the second estimate.

A method of determining a two-dimensional position of a moving wireless device is provided. The method comprises obtaining, for each of three or more base stations, one or more measurements of a carrier frequency offset for one or more signals sent between the moving wireless device and the respective base stations. The method further comprises inputting the carrier frequency offset measurements into a model to determine a two-dimensional position of the moving wireless device, in which inputs to the model do not include range measurements for the moving wireless device with respect to the three or more base stations.

An apparatus, method and computer program is described comprising: generating a first loss function component comprising comparing first location data with first location estimates, wherein the first location estimates are based on channel state data, wherein the first location estimates are generated using a model, and wherein the model comprises a plurality of trainable parameters; generating a second loss function component comprising comparing the first location data with second location estimates, wherein the second location estimates are based on channel state data that have been subjected to a first augmentation and wherein the second location estimates are generated using the model; generating a third loss function component comprising comparing third location estimates based on channel state data and fourth location estimates based on channel state data that have been subjected to a second augmentation, wherein the third and fourth location estimates are generated using the model; and training the trainable parameters of the model by minimising a loss function based on a combination of the first, second and third loss function components.

A method for estimating position of a mobile device which includes receiving, from a network server, observed time difference of arrival (OTDOA) assistance data for a first plurality of cells from a base station almanac (BSA) accessible to the network server. The OTDOA assistance data is stored, within a memory of the mobile device, as a first micro-BSA. A position estimate for the mobile device is determined based upon time difference of arrival (TDOA) measurements associated with an initial subset of the first plurality of cells and initial OTDOA assistance data corresponding to the initial subset of the first plurality of cells. The initial OTDOA assistance data may be generated by the micro-BSA based upon an initial seed estimate.

A communication system has a phased antenna array configured to communicate via a plurality of beams with a wireless device, such as user equipment (e.g., a smart phone). The plurality of beams define a field of view of the phased antenna array, the field of view having a plurality of cells and each of the plurality of beams is associated with one of the plurality of cells within the field of view. A processing device detects the wireless device within the field of view and determines a coarse geographic location of the wireless device within the field of view of the wireless device when the wireless device is within the field of view, or within a cell. The system further determines a fine geographic location for the wireless device based on frequency offset (due to Doppler) and signal flight time.