549 results about "Multilateration" patented technology

The invention comprises of methods and apparatus to estimate the position and velocity of a Mobile Receiver (MR) using either the Time Of Arrival (TOA) of signals received by the MR, their Phase Of Arrival (POA), their Strength Of Arrival (SOA), their Frequency Of Arrival (FOA), or a combination thereof, with respect to a reference produced by a Reference Receiver (RR) of known location. In order to solve for the coordinates of the MR, the invention uses either hyperbolic multilateration based on Time Difference Of Arrival (TDOA), or linear multiangulation based on Phase Difference Of Arrival (PDOA), or both. In order to solve for the velocity of the MR, the patent uses FOA based on Frequency Difference Of Arrival (FDOA). An important contribution of this invention is the way the MR receives, processes and combines available signals for location purposes. Another important contribution of this invention is the way the RR receives, processes and combines available signals for reference purposes. Yet another important contribution of the invention is the application of Super-Resolution (SR) techniques at both the MR and the RR to increase the resolution of the estimated TOAs, POAs, SOAs, or FOAs.

A wireless local area network includes a plurality of access point stations that receive and transmit communications signals within the wireless local area network. A first set of access point stations are WiFi compliant and measure signal strength and determine the received signal strength indication (RSSI). A second set of access point stations are operable in accordance with the time of arrival (TOA) real time location standard (RTLS). A dual mode mobile station is operative for multimode communication with both the WiFi and RTLS compliant access point stations. A location processor is operatively connected with each of the access point stations and processes the RSSI and creates a RSSI locate map and processes communication signals from the second set of access point stations and determines which signals are first-to-arrive signals to locate the mobile station and update the RSSI locate map and locate any non-dual mode WiFi devices.

A method and apparatus of determining a lower bound of an excess delay in a time of arrival measurement of a received signal. Determining the lower bound of an excess delay in a time of arrival measurements includes receiving signals from at least two base stations and determining the time difference of arrival between the received signals from their respective base stations. Then estimating a lower bound of excess delay introduced into the signals received from the base stations based on the time of arrival of the signals from the respective base stations and a known distance between the base stations. The lower bound of excess delay may be used to adjust the estimate of a mobile unit's location based on the time of arrival measurements of the received signals.

The invention consists of methods and apparatus to estimate the position and velocity of a Mobile Receiver (MR) using either the Time Of Arrival (TOA) of signals received by the MR, their Phase Of Arrival (POA), their Strength Of Arrival (SOA), their Frequency Of Arrival (FOA), or a combination thereof, with respect to a reference produced by a Reference Receiver (RR) of known location. In order to solve for the coordinates of the MR, the invention uses either hyperbolic multilateration based on Time Difference Of Arrival (TDOA), or linear multiangulation based on Phase Difference Of Arrival (PDOA), or both. In order to solve for the velocity of the MR, the patent uses FOA based on Frequency Difference Of Arrival (FDOA). An important contribution of this invention is the way the MR receives, processes and combines available signals for location purposes. Another important contribution of this invention is the way the RR receives, processes and combines available signals for reference purposes.

A system of cell phone positioning in real time is provided with specialized location device installations on multiplicity of base stations BSs in CDMA and TDMA cellular communication networks. The purpose of the positioning system is to enable tracking and locating large quantities of anonymous mobile cell phones MS in any number of network cells to be used for real time traffic-forecasting systems, emergency services E911, and other client-initiated position requests. Location data thus obtained can be continuously updated from vehicular-based cellular phones, collected, processed and used as a basis for input to intelligent transportation systems, such as real time urban traffic guidance for vehicular congestion and intelligent traffic control systems. The system is capable of covering large urban geographical areas and number of independent cell structures serving thousands of mobile cell phone clients. It is an independent plug-in solution with specialized synchronized location device installations in each cell BS. Centrally located specialized location software based on Time of Arrival (TOA) and Time Difference of Arrival (TDOA) methods for high speed location processing in central Location Database Server (LDS). The inventive system consists of number of component functions: Operator-initiated functions, location device functions and software enabled positioning functions.

A device for identifying interference source in wireless communications is provided, including a correlation compound module, a matching and screening module, a statistical analysis module, and a match identification module. The correlation compound module uses the time of arrival (TOA) of the burst as the synchronization basis to compound the correlated frequency word, time difference of arrival (TDOA) word, amplitude word and angle of arrival (AOA) word to form a burst descriptor word (BDW). The matching and screening module uses the BWD to match the burst library to screen out the non-interference sources. The statistic analysis module uses the screened outcome for statistical analysis, and obtains a source discriminator file (SDF). The matching and identification module uses the SDF to search the interference source library for matching and obtains an identification result.

The invention relates to a Federated Kalman filtering-based method for fusing multilateration data and radar data, comprising seven processes: pretreatment, time and space registration, error correction, single-sensor line tracking or airborne trace interconnection and filtration, data association, data fusion as well as error estimation. On the basis of multiclass monitoring information, the technical scheme of the invention establishes data association mapping relations among all classes of targets, constructs a process method fusing the multilateration system data and the radar data, realizes deep fusion of all classes of information and comprehensive utilization on effective information, ensures high updating rate of a multilateration system and the whole precision of system monitoringwhen period is less than or equal to 1sec, reduces impact of radar measuring error on system monitoring precision, and significantly improves the tracking precision of the system.

Neighbor cell hearability can be improved by including an additional reference signal that can be detected at a low sensitivity and a low signal-to-noise ratio, by introducing non-unity frequency reuse for the signals used for a time difference of arrival (TDOA) measurement, e.g., orthogonality of signals transmitted from the serving cell sites and the various neighbor cell sites. The new reference signal, called the TDOA-RS, is proposed to improve the hearability of neighbor cells in a cellular network that deploys 3GPP EU-TRAN (LTE) system, and the TDOA-RS can be transmitted in any resource blocks (RB) for POSCH and/or MBSFN subframe, regardless of whether the latter is on a carrier supporting both PMCH and POSCH or not. Besides the additional TDOA-RS reference signal, an additional synchronization signal (TDOA-sync) may also be included to improve the hearability of neighbor cells.

A method of estimating the speed of a WLAN-enabled device in a WLAN positioning system is provided. A method of estimating a speed of travel of a WLAN-enabled device includes the WLAN-enabled device receiving signals transmitted by a WLAN access point in range of the WLAN-enabled device. The signals include a first message and a second message. The method also includes estimating an expected time of arrival of the second message based on an actual arrival time of the first message and determining an actual time of arrival value of the second message. The method further includes determining a time difference of arrival value for the second message based on the actual time of arrival of the second message and the expected time of arrival of the second message and estimating the speed of travel of the WLAN-enabled device based on the time difference of arrival value.

The present invention relates to a navigation unit and base station used for determining location. A plurality of base stations are initialized to determine their location relative to each other. At the navigation unit, the time of arrival of at least one signal from each of the plurality of base stations is measured. From this, the location of the navigation unit relative to the plurality of base stations may be directly calculated using a closed solution. In one embodiment, a time of arrival technique is used and in another embodiment a time difference of arrival technique is used. Preferably an ultra-wide band frequency is utilized.

Location based wireless services in a service provider's network are intertwined with a message database (text and/or audio) to automatically provide location information regarding the subscriber to the message database, without requiring the wireless device itself to provide the location information. A location management system is provided to perform the location management functions of determining subscriber location (e.g., by call/sector ID, angle of arrival (AOA), time difference of arrival (TDOA), time of arrival (TOA)), and of mapping the location to the desired text and/or audio. Speed information may also be determined by the location management system, or the subscriber may be prompted to input a particular mode of transportation, or generally indicate their speed. Of course, the slower the speed of the subscriber, the fewer location updates will be required, lessening the burden on the tour guide system in the wireless network.

According to an embodiment of the present invention jamming energy is allocated to a plurality of emitters based on a three-dimensional (3-D) emitter geolocation technique that determines the geolocation of radio frequency (RF) emitters based on energy or received signal strength (RSS) and/or time differences of arrival (TDOAs) of transmitted signals. The three-dimensional (3-D) emitter geolocations are used to rank emitters of interest according to distance and available radio frequency (RF) jamming energy is allocated to the emitters in rank order. The techniques may be employed with small unmanned air vehicles (UAV), and obtains efficient use of jamming energy when applied to radio frequency (RF) emitters of interest.

A position estimating method and apparatus are disclosed that determine an angle of arrival of a signal received from a terminal; determine a distance of the terminal, using an arrival time difference between the arrival time of the signal and a reference time; and determine a position of the terminal based on the determined angle of arrival and distance.

A wireless localization technology using efficient multilateration in a wireless sensor network is disclosed. After calculating estimated distances from each of at least three reference nodes to a blind node using received signal strength of wireless signals that the at least three reference nodes received from the blind node, the estimated location of the blind node is obtained through multilateration using the calculated estimated distances. To correct error in the estimated location, the estimated distances are used, and the error correction direction and error correction distance for the estimated location are calculated by applying a largest weight to the reference node closest to the estimated location. The error of the estimated location is corrected by move the estimated location of the blind node by the calculated error correction direction and error correction distance. Calculation for the error correction is very simple and fast.

A method and system for synchronizing location finding measurements in a wireless local area network (WLAN) provides a low cost mechanism for correcting location measurements within a WLAN location finding system. Multiple location receivers compute the time-of-arrival (TOA) of a reference transmitter signal, which is generally a beacon signal. The TOAs are collected and reported to a master unit that contains stored predetermined position information for the location receivers. The master unit computes the time-differences-of-arrival (TDOA) between multiple receivers and computes differences between the measured TDOAs and theoretical TDOAs computed in conformity with the predetermined position of each location receiver. The deviations between theoretical and measured TDOAs are collected in a statistical sample set and Kalman filters are used to produce a model of location receiver timebase offset and drift over multiple received beacon signals. The filter outputs are used to then either correct subsequent TDOA measurements for each location receiver, improving the accuracy of subsequent and/or prior TDOA measurements, or commands are sent to the location receivers to calibrate the timebases within the location receivers in order to improve the accuracy of subsequent TOA measurements.

A direct multilateration target tracking system is provided with the TOA time stamp as an input. A technique of tracking targets with varying receiver combinations is provided. Methods of correlating and combining Mode A, Mode C, and Mode S messages to enhance target tracking in a passive surveillance system are provided. A direct multilateration target tracking system is provided by TOA tracking and smoothing. A technique for selecting best receiver combination and/or solution of multilateration equations from a multitude of combinations and/or solutions is provided. A technique for correcting pseudorange values with atmospheric conditions is provided. A technique for improving height determination for regions of poor VDOP in a 3D multilateration system is provided.

A TDOA (time difference of arrival) location system, in which mobile wireless devices broadcast wireless signals which are received by two or more transceivers deployed in the vicinity of the mobile wireless device. Each transceiver measures the TOA (time of arrival) of the received broadcasted signal and reports the TOA to a central server. The central server then calculates the mobile device position using multi-lateration of TDOA values. The system uses fiber optic links between the antennas and the transceivers deployed in the location area to provide unique advantages that couldn't be achieved using RF coaxial cables.