A method for determining a clock drift comprises determining a drift of a clock relative to a reference clock based on two signals from the reference clock and a further signal. The method can be used for time synchronization and is suitable for implementation on resource-constrained devices. An anchor point implementing the method and a real-time locating system comprising such an anchor point are also disclosed.

The present invention discloses a positioning tag operation method includes the steps outlined below. The positioning tag is set in an initializing state to select an available positioning time interval within each positioning periods as a selected positioning time interval and broadcast a connection request signal therein. A time synchronization signal is received from a base station of the positioning system. The time synchronization signal includes information of an assigned positioning time interval corresponding to the positioning tag within each of the positioning periods is determined by the positioning tag, so as to set the positioning tag in a positioning state accordingly and stop receiving the time synchronization signal. The positioning signal is broadcasted in the assigned positioning time interval within each of the positioning periods in the positioning state, and the positioning signal is stopped to be broadcasted in the time other than the assigned positioning time interval within each of the positioning periods.

A method for determining a clock drift comprises determining a drift of a clock relative to a reference clock based on two signals from the reference clock and a further signal. The method can be used for time synchronization and is suitable for implementation on resource-constrained devices. An anchor point implementing the method and a real-time locating system comprising such an anchor point are also disclosed.

A method for determining the time of receipt by a radio receiver of a binary coded radio message emitted by a sender. A radio signal containing the message is received by the receiver. An analog electrical signal is generated, sampled and optionally demodulated. The data content of the message is determined based upon the demodulated signal as a stream of data bits. The stream of data bits comprises a predetermined signal element whose time of receipt is determined. A digitally stored, constructed comparison signal is created based upon the stream of data bits. The constructed comparison signal is constructed to correspond to the sampled signal, in that a time variable which maximizes a correlation between the constructed comparison signal and the sampled signal is determined, and in that the time variable is then used to correct the time determination of the receipt of the predetermined signal element.

A split architecture is disclosed for determining the location of a wireless device in a heterogeneous wireless communications environment. A detector within the device or another component of the environment receives signals including parameters for a localization signal of the device. The parameters describe known in advance signals within the signals. Additional metadata including each frame start of the signals and assistance data and auxiliary information are also received. The known in advance signals are detected based on the parameters of the localization signal. Samples extracted from the known in advance signals are then processed and compressed and sent with other collect data to a locate server remote from the detector. The location server uses that information as well as similar information about the environment to calculate the location of the device, as well as perform tracking and navigation of the device, and report such results to the environment.

An apparatus of an LMF node includes processing circuitry coupled to a memory. To configure the LMF node for UE location determination in a 5G NR network, the processing circuitry is to decode a measurement report message from a first Next Generation Node-B (gNBi). The measurement report message indicates a time difference (Δtij) between an actual measured propagation time delay (tij) and a reference propagation time delay (Tij) between the gNBi and at least a second gNB (gNBj). The processing circuitry further performs an estimation of a UE location based on the measurement response and adjusts the estimation based on the time difference.

A method for sensor operation includes deploying a network of sensors, which have respective clocks that are not mutually synchronized. At least a group of the sensors receive respective signals emitted from each of a plurality of sources, and record respective times of arrival of the signals at the sensors according to the respective clocks. Location information is provided, including respective sensor locations of the sensors. The respective clocks are synchronized based on the recorded times of arrival and on the location information. In the process the sources may be localized, or if the sources are far away, then their directions may be resolved. Sensor positions may also be resolved in the process.

A wireless network including user equipment (UE) and base stations is configured to perform position determination with low latency and synchronized to a common time within a wireless network. The UE and base stations are configured to perform positioning measurements at a specific time point or within a window around the time point in a measurement period. The time point may be relative to a timing event within the wireless network, such as the beginning or end of a positioning reference signal window or a specific message in a layer 1 or layer 2 transmission. A location server may be provided with the positioning measurements or a position estimate from the UE and provide the position estimate to an external client within the measurement period.

This disclosure concerns estimating the location of a transmitter using multiple pairs of locator nodes with known locations and measuring time of arrival of a signal received from a transmitter. A processor of a location estimation node first determines time difference of arrival values from time of arrival values measured by each pair of locator nodes. The processor then determines likelihood information for multiple candidate locations of the transmitter and estimates the location of the transmitter from the likelihood information. A processor further determines an initial time of arrival value for the received signal and channel impulse response for a radio channel between the transmitter and receiver. The processor then determines a time correction from the channel impulse response based on a first peak of the channel impulse response and a leading edge of the first value. The processor finally determines an improved time of arrival value of the received signal.

In an aspect, a UE obtains a plurality of positioning reference signal (PRS) configurations. The UE receives, from a BS, an L1 or L2 message that indicates one of the plurality of PRS configurations, which in turn triggers an aperiodic or semi-periodic PRS procedure in accordance with the indicated PRS configuration.