Abstract: A method of driving a mobile communication terminal in a cellular network, includes monitoring with a control unit of the mobile communications terminal, reception power levels between the mobile communication terminal and cellular network base stations at a predefined monitoring rate for each base station. Timing information values for a number of base stations are intermittently monitored by the control unit. Drift of the timing information values for at least two of the base stations is monitored and significant motion of the mobile communication terminal is deemed detected if at least one of the timing information values indicates a drift equal to or exceeding a given timing drift threshold. The predefined reception power level monitoring rate is reduced to a reduced reception power level monitoring rate for at least a number of the base stations as long as the motion of the mobile communication terminal is not significant.

Abstract: Disclosed is a localization method of multiple based on a TDOA method, including calculating TDOA measurements step S100 of arranging multiple sensors, and calculating TDOA measurement values while a reference sensor is changed, in turn; locating multiple jammers using all TDOA measurements step S200 of calculating estimated location solutions of the multiple jammers; a finding a searching quadrant step S300 of finding a quadrant having the highest density of the estimated location solutions; a setting a searching range and detecting searching cell step S400 of deciding a searching range, and searching the searching cell; and determining estimated positions of the multiple jammers step S500 of deciding the number of the jammers, and calculating location solutions of the multiple jammers. Therefore, the present invention can accurately localize the multiple jammers.

Abstract: In general, the subject matter described in this specification can be embodied in methods, systems, and program products for identifying a location of a mobile computing device. A first location estimate of a mobile computing device and an accuracy of the first location estimate is determined at a mobile computing device based on wireless signals received from one or more beacons. A time period based on the accuracy of the first location estimate is determined. One or more subsequent location estimates of the mobile computing device and respective accuracies are determined. The determination of the subsequent location estimates is stopped at an end of the time period. A preferred location estimate from the determined location estimates is determined at the mobile computing device.

Abstract: A technique for determining the position of a mobile device includes receiving at the mobile device a set of time-slotted messages from a respective set of reference devices. Each of the time-slotted messages contains a slot ID indicating the assigned time slot in which it was broadcast. The slot ID is used to determine the time of transmission of each of the time-slotted messages received at the mobile device, and the position of the mobile device is determined via multi-lateration based on the time of flight of the time-slotted messages and known positions of the reference devices. According to another approach, the mobile device receives a set of ADS-B messages from a respective set of SBS ground stations. The time of transmission of each of the ADS-B messages is supplied in the ADS-B message itself or in a subsequent message and used to determined the position of the mobile device.

Abstract: A wireless positioning server using clock offset compensation and a wireless positioning method using the same. The wireless positioning server using clock offset compensation estimates a precise position of a tag requiring position information by effectively predicting information regarding a distance between a beacon for performing positioning and the tag requiring position information. An error in the positioning estimation result due to a clock offset is minimized by measuring a relative clock frequency ratio between beacons and by compensating for clock frequencies of the beacons when a distance between a beacon and a tag is estimated.

Abstract: A method and apparatus for assisting the calculation of the position of a receiver device (1200), by observing a transmitted signal having a known structure. The method comprises: comparing (S220) the time of arrival, at a reference position (X1), of a first portion of the signal with the time of arrival at the receiver, at an unknown position (Y1), of a second portion of the signal; obtaining (S230) a local wave propagation model of the signal, the model comprising an estimate of the direction of propagation of the signal in the neighbourhood of the reference position and unknown position; and using (S240) the direction of propagation and the result of the comparison to assist in the calculation of the unknown position relative to the reference position.

Abstract: A method and a system are provided which are able to utilize indirect paths of signals of UWB type to locate a wireless communication node possessed by a body. The present method and system can notably apply to cooperative body networks implementing several wireless nodes able to communicate with one another.

Abstract: A GNSS receiver communicates with any connectivity device, such as a WiFi device that is, in turn, in communication with a wired network having access to the DTI timing. Such connectivity devices may set their timing and frame synchronization to the DTI and thus serve as Geoposition beacons, thereby enabling the GNSS receiver to accurately determine its position. The GNSS receiver may also use the DTI timing supplied by such a network to perform relatively long integration time so as to achieve substantially improved sensitivity that is necessary for indoor Geopositioning applications. Furthermore, the GNSS data, such as satellite orbital information, may also be propagated by such devices at high speed. By providing this data to the GNSS receivers via such connectivity devices in a rapid fashion, the GNSS receivers are enabled to receive the transmitted data associated with the satellite without waiting for the GNSS transmission from the satellites.

Abstract: A method estimates the time-of-arrival (ToA) of signals received via multipath channels. The received signal of a number of trials is first passed through a band-pass filter and then sampled. The presence of a channel tap within a time window is estimated by comparing a threshold to a largest eigenvalue of the covariance matrix of a time window. The signal samples are used to calculated a band region of a complete covariance matrix. After the band region has been updated for all signal samples, the covariance matrices for a moving window can be extracted from the band region. The ToA is estimated as the ending time of the leading window, which is the earliest window, such that the largest eigenvalue is larger than a given threshold.

Abstract: In a network-based Wireless Location System (WLS), geographically distributed Location Measurement Units (LMUs) must be able to detect and use reverse channel (mobile to network) signals across multiple BTS coverage areas. By using Matched Replica correlation processing with the local and reference signals subdivided into discrete segments prior to correlation, the effects of mobile clock drift and Doppler shifts can be mitigated allowing for increased processing gain. By using historical network and real-time data about the radio signal and/or radio channel, the segmentation and computation scheme may be optimized to reduce latency and enhance capacity while maximizing location accuracy.

Abstract: Systems and methods disclosed herein can implement a femtocell calibration solution that uses the known location of the femtocell to calibrate timing based locating systems. The calculated time differences of different signals sent between macrocells and a mobile device can be used to solve for a reference time difference that accounts for the timing differences of the unsynchronized macrocells. The reference time difference can then be used to solve for the location of another mobile device if the calculated time differences between that mobile device and the macrocells are known. The solution can include taking many measurements of the calculated time difference at the first mobile device in order to average them to get a more accurate reference time difference. The solution can further include ceasing measurements at the first mobile device when the mobile device is no longer within range of the femtocell.

Abstract: A method for determining a time difference between a first and a second time of arrival of the signal is described, the method including: receiving a first representation of the signal at the first time of arrival; receiving a second representation of the signal at the second time of arrival; correlating at least a first time-domain representation of the signal and a second time-domain representation of the signal to obtain a first time difference information; evaluating a phase difference relation between a first frequency-domain representation of the signal and a second frequency-domain representation of the signal to obtain a second time difference information; and determining the time difference between the first and the second time of arrival of the signal based on the first and the second time difference information, or based on a time difference information derived from the first time difference information and the second time difference information.

Abstract: The present invention discloses a radio beacon coupled to an altimeter, for GPS positioning in an elevator, configured to broadcast signals forcing a nearby GPS receiver to read constant latitude and constant longitude, associated with the position of the elevator shaft, and altitude associated with the altimeter reading. The acquired in-elevator position can serve as an initial fix for further navigation, particularly indoors.

Abstract: This invention builds on previous industry techniques to correlate data from a variety of sources for the purposes of tracking and identifying aircraft, vehicles, and marine vessels in real time over a variety of different areas including oceans and mountainous terrain. Passive broadband tracking of aircraft emitters, and electronic fingerprinting of emitters, correlated with audio, video, infrared, primary radar and other information is employed to provide a comprehensive assessment of an aircraft's position, track and identification for a variety of applications including homeland security and search and rescue.

Abstract: A system for determining a location of a receiver is disclosed. The system includes at least one transmitter transmitting one or more radio signals, respectively. The system also includes a receiver comprising a clock, a memory, and a processor configured to execute computer-executable instructions stored in the memory. The instructions makes the receiver operable to receive the radio signals, capture the radio signals as one or more received signal waveform, respectively, and store the received signal waveforms in the memory. The instructions also make the receiver operable to calculate one or more virtual transmitted waveforms based upon the received signal waveforms, respectively and determine, based upon the received signal waveforms and the virtual transmitted waveforms, a position of the receiver relative to the transmitters.

Abstract: A position location system comprises transmitters that broadcast positioning signals. Each broadcasted positioning signal comprises a pseudorandom ranging signal. The position location system includes a remote receiver that acquires and measures the time of arrival of the positioning signals received at the remote receiver. During an interval of time, at least two positioning signals are transmitted concurrently by the transmitters and received concurrently at the remote receiver. The two positioning signals have carrier frequencies offset from one another by an offset that is less than approximately twenty-five percent of the bandwidth of each positioning signal of the two positioning signals. Cross-interference between the positioning signals is reduced by tuning the remote receiver to a frequency of a selected signal of the two positioning signals and correlating the selected signal with a reference pseudorandom ranging signal matched to a transmitted pseudorandom ranging signal of the selected signal.

Abstract: A position location system comprises transmitters that broadcast positioning signals. Each broadcasted positioning signal comprises a pseudorandom ranging signal. The position location system includes a remote receiver that acquires and measures the time of arrival of the positioning signals received at the remote receiver. During an interval of time, at least two positioning signals are transmitted concurrently by the transmitters and received concurrently at the remote receiver. The two positioning signals have carrier frequencies offset from one another by an offset that is less than approximately twenty-five percent of the bandwidth of each positioning signal of the two positioning signals. Cross-interference between the positioning signals is reduced by tuning the remote receiver to a frequency of a selected signal of the two positioning signals and correlating the selected signal with a reference pseudorandom ranging signal matched to a transmitted pseudorandom ranging signal of the selected signal.

Abstract: A system and method of communicating signals is provided. The system includes a plurality of satellites, at least one receiver, and at least one satellite uplink station. The plurality of satellites include at least one active satellite. The at least one receiver is in communication with the plurality of satellites, and receives a signal from the at least one active satellite. The at least one satellite uplink station is in communication with the plurality of satellites, and transmits the signal and alters a frequency of the signal based upon a location of the at least one active satellite to reduce a Doppler frequency shift when activating and deactivating the plurality of satellites.

Abstract: We describe a device that is able to compute its range and time offset relative to another similar device, and thereby also a three-dimensional position, speed and time relative to other similar devices provided that at least four are present and within range. It does so by transmitting at least two signals at different frequencies and by receiving similar signals transmitted by the other devices. The signals are constructed so that they are independent of the radio band used and so that they lead to cancellation of common-mode effects in the transmitter and receiver circuits. No fixed infrastructure of transmitters, receivers or local measurement units is required and the devices do not need to be synchronized. The system scales to very large networks of devices in which they work collectively each solving a part of the problem that describes the relative positions of all interconnected devices.

Abstract: A sensor system having a sensor module and an induction unit is provided, the sensor module having a first antenna, and the induction unit having a second and a third antenna, an induction transmission of signals being provided between the first and the second antenna, and the signals being sent and/or received electromagnetically by the third antenna.

Abstract: According to an embodiment of the present invention, geolocations of multiple unknown radio frequency (RF) signal sources are determined using three-dimensional (3-D) geolocation techniques. The three-dimensional (3-D) geolocation techniques obtain reliable geolocation estimates of radio frequency (RF) emitters based on energy or received signal strength (RSS) of emitter transmitted signals and based on their time differences of arrival (TDOAs) at various sensor locations. The energy based geolocations and the time difference of arrival (TDOA) geolocations are combined to determine an overall set of geolocations for multiple unknown radio frequency (RF) signal sources. The geolocation information is used to track and monitor the locations of the multiple emitters.

Abstract: A technique for determining the position of a mobile device includes receiving messages from respective mobile reference devices. Each of the messages is broadcast beginning at one of several predetermined message start opportunity (MSO) times that have known timings relative to a reference time. Each of the messages contains a MSO value identifying the MSO time at which transmission of the message started. The MSO value is used to determine the time of transmission of each of the messages received at the mobile device, and the position of the mobile device is determined via multi-lateration. According to another approach, the mobile device receives a set of ADS-B messages from a respective set of mobile reference devices. The time of transmission of each of the ADS-B messages is supplied in the ADS-B message itself or in a subsequent message and used to determine the position of the mobile device.

Abstract: A method and system of determining the position of a radio signal transmitter are described. The method includes determining the type of radio signal being transmitted from the radio signal transmitter by analysing radio signal characteristics and correlating different sets of information to determine the position of the radio signal transmitter. Each set of information corresponds to a different relative position of at least one receiver to the transmitter and includes radio signal data derived from radio signals received by the at least one receiver from the transmitter at each respective relative position and positioning data containing information about the position of the at least one receiver at each respective relative position.

Abstract: There is provided a method and system for positioning a transponder, the system comprising an antenna array of at least two spaced-apart antennas coupled to a common generating and switching unit. The generating and switching unit is configured for generating a periodic signal and switching the signal between said at least two antennas, constituting a positioning signal transmitted to the transponder. The system comprises a receiver for receiving a returned signal and a phase difference estimator coupled to the receiver and operable to measure phase differences between portions of the returned signal. The system further comprises a positioning utility coupled to said phase difference estimator and configured to determine the position of the transponder relative to the positioning system.

Abstract: The present invention provides a system and method for aircraft to determine own position and navigate using a navigation heartbeat signal broadcast on a DME uplink and/or a Mode-S uplink frequency. The present invention enables deep integration between the existing navigation systems (DME interrogation-reply ranges and GPS/WAAS raw TDOA or pseudo range measurements) and the DME heartbeat TDOAs or Mode-S heartbeat TDOAs to provide a highly accurate navigation positioning capability and provide necessary backup capability in lieu of GPS to maintain the necessary RNP/RNAV capability and avoid degrading aircraft operational safety.

Abstract: A system and method for locating mobile stations in a wireless communication system such as a cellular system based on at least one received wireless signal and a database of geographical information.

Abstract: A location system comprising a plurality of base units for enabling the locating of a device by means of one or more location signals communicated between the device and the base units and signal processing equipment for: i. determining the location of the device in dependence on the manner in which the location signal(s) is/are received and ii. deriving calibration data for calibrating the system in dependence on the manner in which the location signal(s) is/are received.

Abstract: The present invention addresses the resolving of the problems associated with the passive location of targets in TOA (Time of Arrival) or TDOA (Time Difference of Arrivals) mode. The method of passively locating a target in TOA or TDOA mode implements a meshing (subdivision) into blocks of the space in which the location area is situated. The set of the blocks that form this mesh is analyzed iteratively. On each iteration, each block of interest is subdivided into smaller identical subblocks. A block of interest is, according to the invention, a block including at least one point belonging to the location area being sought for which the shape is to be determined. The iterative process is stopped when the size of the subblocks obtained on the current iteration corresponds to the desired resolution. The invention applies in particular to the 2D or 3D location systems that include TOA and TDOA modes or mixed modes.

Abstract: Methods of selecting a transmitter power for a mobile telephone include receiving a telephone number and transmitting a control message associated with selection of a transmitter power if the telephone number meets a predetermined criterion. For example, if the telephone number is an emergency service number or number associated with a navigation assistance service, the control message is transmitted.

Abstract: Propagation time for a target signal path is determined by detecting and processing a plurality of unknown signals received at two locations. A third location is established, such that the propagation time between the third location and one of the two locations is known, and the signal path between the third location and the other of the two locations is the target signal path. The two locations are monitored for any signals that may be detected. Signals received at the two locations are processed to determine which signals have a common source, and of the signals having a common source, the signal having the greatest delay between times of reception at the two locations is selected. The selected signal is used to determine the propagation time between the two locations.

Abstract: A method for measuring the time of arrival of radio signals within a network comprises receiving the received signals including at least a first pseudorandom code and a second pseudorandom code from at least one other node; identifying a frequency difference between the node and the other node using a phase difference between each of a maximum value of a cross-correlation provided by the first pseudorandom code and the second pseudorandom code; applying the frequency difference to the reception of the received signal; and calculating the time of arrival of the received signal comprising a time, measured with a local clock, when the cross-correlation has achieved the maximum value.

Abstract: A method (300, 500) and apparatus (200) that transmits and/or receives positioning reference signals in a wireless communication network using a mixture of cyclic prefix types. The method may include configuring (320) subframes in the wireless communication network as multicast broadcast single frequency network subframes. The method may include configuring (330) subframes in the wireless communication network as positioning subframes including positioning reference signals. The method may include determining (340) whether all of the positioning subframes are multicast broadcast single frequency network subframes. The method may include generating (350) extended cyclic prefix positioning reference signals for all of the positioning subframes if all of the positioning subframes are multicast broadcast single frequency network subframes.

Abstract: A system for locating an object in a GPS-denied environment includes first and second stationary nodes of a network and an object out of synchronization with a common time base of the network. The system includes one or more processors that are configured to estimate distances between the first stationary node and the object and a distance between the second stationary node and the object by comparing time-stamps of messages relayed between the object and the nodes. A position of the object can then be trilaterated using a location of each of the first and second stationary nodes and the measured distances between the object and each of the first and second stationary nodes.

Abstract: A locating system, includes at least one initiator configured to operate at a first clock frequency, and to transmit a measurement signal including a first preamble; and at least one transponder configured to operate at a second clock frequency, to receive the measurement signal, and to transmit a response signal to the initiator, the response signal including a second preamble. The initiator is further configured to calculate, based on the response signal, a distance between the initiator and the transponder for determining a location of the transponder.

Abstract: A leading edge associated with a received signal is detected to provide, for example, time of arrival information for a ranging algorithm. In some aspects, a method of leading edge detection involves sampling a received signal, generating a drift compensated signal based on the samples, reconstructing the received signal based on the drift compensated signal, and identifying a leading edge associated with the received signal based on the reconstructed signal.

Abstract: Example methods, apparatuses, and articles of manufacture are disclosed herein that may be utilized to facilitate or otherwise support RF ranging-assisted local motion sensing based, at least in part, on measuring one or more characteristics of a range between communicating devices in one or more established RF links.

Abstract: Embodiments of a system and method for determining an angle-of-arrival (AOA) of signals received from a transmitting device are shown. Signals from the transmitting device are received through two or more pairs of spatially-diverse antennas. A non-inverted version of the signals received through a first antenna of a pair is injected into a first input of a surface-acoustic-wave (SAW) device. An inverted version of the signals received through a second antenna of the pair is injected into a second input of the SAW device. Signals present at tap outputs are processed to determine a time-difference-of-arrival (TDOA) between the signals received through each pair of antennas. The AOA may be calculated from the TDOAs determined from two or more pairs of antennas.

Abstract: A method for measuring a location of a mobile terminal includes calculating first location information by using a ToA (Time of Arrival) scheme, calibrating the first location information by using angle information between two base stations and the terminal; calculating second location information by using an AoA (Angle of Arrival) scheme, and calculating a location value of the terminal by using the calibrated first location information and the second location information.

Abstract: A multicarrier modulation position determination method that includes deploying at least one known receiver with a known location and a second receiver with an unknown location. At least two signals of opportunity with different locations are obtained by both the receiver and the second receiver. The signals having a plurality of block data, the block data having block boundaries. The block boundaries including a beginning block boundary and an end block boundary. The block data further including a cyclic prefix at the beginning block boundary. Acquiring a plurality of data samples for at least a portion of the block data and correlating the attained signal of opportunity between the receivers. The correlating process includes the calculation of a time difference of arrival between the known receiver and the second receiver. The time difference of arrival is calculated by aligning the block boundaries and computing a single scalar statistical feature associated with each block.

Abstract: A system and method are disclosed to track aircraft or other vehicles using techniques including multilateration and elliptical surveillance. Unlike conventional approaches that use time difference of arrival for multilateration at a fixed set of reception points, this technique allows targets to be tracked from a number of dynamic or moving reception points. This allows for triangulation/multilateration and elliptical surveillance of targets from combinations of fixed, fixed and moving or only moving ground-based receivers, sea-based receivers, airborne receivers and space-based receivers. Additionally this technique allows for ADS-B validation through data derived from only two receivers to assess the validity and integrity of the aircraft self-reported position by comparing the time of arrival of the emitted message at the second receiver to the predicted time of message arrival at the second receiver based on the self-reported position of the aircraft and the time of arrival at the first receiver.

Abstract: Transmitters are located with a network of sensors by measuring signal characteristics at multiple known locations and processing these measurements at a central node. The sensors communicate their location to the central node along with measured characteristics of the transmitter's signal, and may be required to synchronize with other sensors. Often, GNSS receivers are utilized to locate and synchronize the sensors. However, the GNSS signals may be attenuated by obstructions. In this case, the sensors determine their location by making ranging measurements with sensors that can receive the GNSS signals. The waveform for the wireless backhaul permits this ranging. Additionally, many sensors can determine their location and time synchronize with the geolocation network through reception of signals from other sensors even if they do not have a direct connection to sensors that know their location and are time synchronized.

Abstract: A secure communication topology can be used for communications between a locator and one or more transponders to determine the location of the transponders. An example system may include a locator that is configured to transmit an interrogation signal that is encoded for receipt by one or more of the transponders. When a transponder receives and correlates the interrogation signal with an internally stored reference sequence, the transponder can transmit one or more reply transmissions at precisely determined time delay intervals. The time delay intervals are secretly known by both the locator and the transponder. The reply transmissions can each correspond to previously sampled noise signals that are also secretly known by both the transponder and the locator.

Abstract: Digital watermark detection apparatus including detection units which calculate detected values of watermark signals by use of keys for PCM data of channels of audio content, a plurality of units which add the detected values corresponding to each of the channels and each of the keys for each possible combination of the respective channels and the respective keys, and a unit which selects and outputs one adding result from the respective adding results by the plurality of detected value adding units. Moreover, it includes units which accumulate the detected values in accumulation cycles different from one another to restore messages embedded as digital watermarks from the accumulated detected values, and perform boundary detection of the audio contents to detect the audio contents in which the digital watermarks are embedded, and a detection result output unit which synthesizes and outputs respective processing results by the message restoration units.

Abstract: Method for determining an arrival time of a RF ranging signal at a ranging receiver, comprising receiving at least one RF ranging signal via a plurality of antennas comprised by the ranging receiver, providing a plurality of antenna signals, each comprising at least a section of the ranging signal as received either by a respective one of the antennas or by a linear combination of at least two of the antennas, determining respective candidate arrival times of the at least one ranging signal from at least two of the antenna signals and determining the arrival time of the at least one ranging signal as the earliest candidate arrival time.

Abstract: Propagation time for a target signal path is determined by detecting and processing a plurality of unknown signals received at two locations. A third location is established, such that the propagation time between the third location and one of the two locations is known, and the signal path between the third location and the other of the two locations is the target signal path. The two locations are monitored for any signals that may be detected. Signals received at the two locations are processed to determine which signals have a common source, and of the signals having a common source, the signal having the greatest delay between times of reception at the two locations is selected. The selected signal is used to determine the propagation time between the two locations.

Abstract: Provided is an apparatus and method for computing the location of a radio beacon by using Time Difference Of Arrival (TDOA) and multiple frequencies. The apparatus and method of the present invention compute the location of a radio beacon without limitation in distance by using multiple frequencies and time difference of arrival to resolve the problem of phase ambiguity. A radio beacon location computing system includes a plurality of base stations configured to receive signals of multiple frequencies transmitted from the radio beacon, and detect and output phase differences and arrival time; and a location computing server configured to receive the phase differences and the arrival time outputted from the respective base stations, acquire calculation distances based on the phase differences, remove phase ambiguity from the calculation distances based on the arrival time, and compute the location of the radio beacon.

Abstract: Methods and systems for determining the distance between two objects and optionally activating an alarm when the distance exceeds a predetermined threshold. The detection system includes a base unit and a remote unit. The base unit includes a first transmitter for transmitting at least one locator pulse; a first receiver for receiving at least one return pulse, the first receiver including a pulse detector for detecting the leading edge of the at least one return pulse; and a distance measurement unit. The remote unit includes a second receiver for receiving the at least one locator pulse; and a second transmitter for transmitting the at least one return pulse in response to the at least one locator pulse. The distance measurement unit is adapted for determining the distance between the base unit and the remote unit based on the leading edge of the at least one return pulse.

Abstract: Methods for estimating a distance between an originator and a transponder, methods for calculating a fine time adjustment in a radio, computer-readable storage media containing instructions to configure a processor to perform such methods, originators used in a system for estimating a distance to a transponder, and transponders used in a system for estimating a distance to an originator. The methods utilize fine time adjustments to achieve sub-clock cycle time resolution. The methods may utilize offset master clocks. The methods may utilize a round-trip full-duplex configuration or a round-trip full-duplex configuration. The method produces accurate estimates of the distance between two radios.

Abstract: A method for improving the results of radio location systems that incorporate weighted least squares optimization generalizes the weighted least squares method by using maximum a posteriori (MAP) probability metrics to incorporate characteristics of the specific positioning problem (e.g., UTDOA). Weighted least squares methods are typically used by TDOA and related location systems including TDOA/AOA and TDOA/GPS hybrid systems. The incorporated characteristics include empirical information about TDOA errors and the probability distribution of the mobile position relative to other network elements. A technique is provided for modeling the TDOA error distribution and the a priori mobile position. A method for computing a MAP decision metric is provided using the new probability distribution models. Testing with field data shows that this method yields significant improvement over existing weighted least squares methods.

Abstract: A network node such as a positioning node, and a related method of determining an uncertainty of a timing measurement used for positioning of a wireless device are disclosed. The method includes estimating a timing measurement uncertainty, and determining if an uncertainty reducing measurement is available. If an uncertainty reducing measurement is available, the method also comprises determining a timing measurement uncertainty based on the estimated timing measurement uncertainty and the uncertainty reducing measurement.