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.

A communication device including a clock, a memory, and at least one processor is disclosed. The at least one processor is configured to execute instructions stored in the memory that cause the at least one processor to perform operations including receiving at least one message from a second communication device of a plurality of communication devices over a preconfigured time duration, determining a first local time of the clock of the communication device at which the at least one message from the second communication device is received, and determining a sync-time of the second communication device based on the at least one message from the second communication device. The operations include mapping the sync-time of the second communication device based on the first local time and the determined sync-time of the second communication device and adjusting a sync-time of the communication device based on the second local time.

A communication device including a clock, a memory, and at least one processor is disclosed. The at least one processor is configured to execute instructions stored in the memory that cause the at least one processor to perform operations including receiving at least one message from a second communication device of a plurality of communication devices over a preconfigured time duration, determining a first local time of the clock of the communication device at which the at least one message from the second communication device is received, and determining a sync-time of the second communication device based on the at least one message from the second communication device. The operations include mapping the sync-time of the second communication device based on the first local time and the determined sync-time of the second communication device and adjusting a sync-time of the communication device based on the second local time.

The present disclosure describes systems and methods for time-of-arrival (TOA) estimation techniques. Some embodiments of the disclosure provide for estimating radio propagation path parameters based on a training signal received over a set of active frequencies. The radio propagation path parameters (e.g., fading coefficients for each path) are used to reconstruct a channel frequency response on null frequencies (e.g., frequencies that did not include or carry the received training signal). A time-of-arrival parameter can then be estimated based on the estimated channel frequency response and the reconstructed channel frequency response (e.g., the channel frequency response estimated using both active frequencies and null frequencies).

A user equipment (UE) in a vehicle (V-UE) broadcasts multi-phased ranging signals with which other entities may determine the range to the V-UE. The multi-phased ranging signals may include a first message, which may be broadcast in the Intelligent Transport System (ITS) spectrum, includes ranging information, such as a source identifier, location information for the broadcasting V-UE, and an expected time of broadcast of the ranging signal. The ranging signal may then be broadcast at the expected time and may include the source identifier. A second message, which be broadcast in the ITS spectrum, may include clock error information for the V-UE. A receiving entity may determine the range to the V-UE based on the time of arrival of the ranging signal and the expected time of transmission, as well as the clock error information. The receiving entity may further generate a position estimate based on the received location information.

Techniques for efficient and accurate data collection employing many sensors distributed over an area is disclosed. The many data collection and transmission devices transmit the data in a novel manner that is the combination of a set of digital data packets which convey the data, integrated with a set of analog packets that enable the receiver to determine the distance between the transmitter and the receiver is disclosed. The receivers of this data are arranged so that they can receive each broadcast sample, and distributed geographically so that tri angulation techniques can be used to precisely locate each transmitter. Highly accurate clocks located only in the receivers are used to timestamp the acquired data. This design of the combination data packet enables use of inexpensive sensors to collect high quality data with accurate two and three-dimensional location and time stamps provided by the network of receivers.

A device is arranged for determining a first distance according to a ranging protocol using a measurement message from a second device. A cooperating device (130) has a directional antenna (133) and is located at a trusted distance (150) sharing a connecting direction (160) with the first device. The cooperating device determines a third direction of the same measurement message, and transfers support data to the first device based on the third direction. The first device first determines a first angle (161) between the first direction and the connecting direction and obtains a third angle (163) between the third direction and the connecting direction using the support data. Then a verification test is performed on the first distance (151), the trusted distance (150), the first and the third angle. The first distance is reliable when said distances and angles correspond to a viable spatial constellation (100) of the devices.

A device is arranged for determining a first distance according to a ranging protocol using a measurement message from a second device. A cooperating device (130) has a directional antenna (133) and is located at a trusted distance (150) sharing a connecting direction (160) with the first device. The cooperating device determines a third direction of the same measurement message, and transfers support data to the first device based on the third direction. The first device first determines a first angle (161) between the first direction and the connecting direction and obtains a third angle (163) between the third direction and the connecting direction using the support data. Then a verification test is performed on the first distance (151), the trusted distance (150), the first and the third angle. The first distance is reliable when said distances and angles correspond to a viable spatial constellation (100) of the devices.

A ranging method in a synchronization system is provided. The ranging method is applied to a first terminal device and includes: sending a first ranging signal to a second terminal device; and determining a first time difference, the first time difference is a time difference between a moment when the first terminal device sends the first ranging signal and a first terminal timing, the first time difference is configured to determine a distance between the first terminal device and the second terminal device in combination with a second time difference, and the second time difference is a time difference between a moment when the second terminal device receives the first ranging signal and a second terminal timing.

A ranging method in a synchronization system is provided. The ranging method is applied to a first terminal device and includes: sending a first ranging signal to a second terminal device; and determining a first time difference, the first time difference is a time difference between a moment when the first terminal device sends the first ranging signal and a first terminal timing, the first time difference is configured to determine a distance between the first terminal device and the second terminal device in combination with a second time difference, and the second time difference is a time difference between a moment when the second terminal device receives the first ranging signal and a second terminal timing.