Patent application number | Description | Published |
20080248811 | TDOA/GPS Hybrid Wireless Location System - A method and system for enhancing the accuracy and robustness of locations determined for a mobile wireless transceiver in a cellular telephone communications system integrating location-related information both from an assisted GPS device embedded in the mobile unit and from infrastructure-based facilities that extract signal characteristic data at networked base stations. Available supporting collateral information may be additionally evaluated in the location determinations to provide location estimates of enhanced robustness and accuracy. | 10-09-2008 |
20080261611 | Sparsed U-TDOA Wireless Location Networks - In an overlay, U-TDOA-based, Wireless Location System, LMUs typically co-located with BTSs, are used to collect radio signaling both in the forward and reverse channels. Techniques are used to compensate for sparse LMU deployments where sections of the U-TDOA service area are uplink demodulation or downlink beacon discovery limited. | 10-23-2008 |
20080261612 | Sparsed U-TDOA Wireless Location Networks - In an overlay, U-TDOA-based, Wireless Location System, LMUs typically co-located with BTSs, are used to collect radio signaling both in the forward and reverse channels. Techniques are used to compensate for sparse LMU deployments where sections of the U-TDOA service area are uplink demodulation or downlink beacon discovery limited. | 10-23-2008 |
20080261613 | Sparsed U-TDOA Wireless Location Networks - In an overlay, U-TDOA-based, Wireless Location System, LMUs typically co-located with BTSs, are used to collect radio signaling both in the forward and reverse channels. Techniques are used to compensate for sparse LMU deployments where sections of the U-TDOA service area are uplink demodulation or downlink beacon discovery limited. | 10-23-2008 |
20080261614 | Sparsed U-TDOA Wireless Location Networks - In an overlay, U-TDOA-based, Wireless Location System, LMUs typically co-located with BTSs, are used to collect radio signaling both in the forward and reverse channels. Techniques are used to compensate for sparse LMU deployments where sections of the U-TDOA service area are uplink demodulation or downlink beacon discovery limited. | 10-23-2008 |
20090143018 | Automated Configuration of a Wireless Location System - In an overlay, network-based Wireless Location System, Location Measurement Units (LMUs) are used to collect radio signaling both in the forward and reverse channels for use in TDOA and/or AoA positioning methods. Information broadcast from the radio network and by global satellite navigation system constellations can be received by the LMUs and used to reduce the difficulty of initial system configuration and reconfiguration due to radio network changes. | 06-04-2009 |
20090149132 | Detection of Time of Arrival of CDMA Signals in a Wireless Location System - In a Wireless Location System (WLS) deployed in connection with a CDMA-based wireless communications system, Location Measurement Units are used to collect multi-path corrupted radio signaling for use in time difference of arrival (TDOA) and hybrid positioning methods. Signal processing techniques are used to enhance the WLS's ability to determine the minimally time-delayed multi-path component and thus increase the accuracy of the TDOA location in CDMA-based wireless communications systems. The signal processing includes a filtering technique for reducing the leading sidelobes of the cross-correlation function as well as a leading edge discovery procedure. | 06-11-2009 |
20100039320 | Hybrid GNSS and TDOA Wireless Location System - A method and apparatus for position determination is provided using measurements from both Global Positioning System (GPS) receivers and terrestrial-based Uplink Time Difference of Arrival (UTDOA) receivers. The method involves the transformation of downlink satellite measurements into equivalent UTDOA measurements by computing comparable cross-correlation coefficients and time differences of arrival with respect to a UTDOA reference station. The method includes a weighting operation whereby the relative weights of the UTDOA measurements and the relative weights of the GPS measurements are adjusted based on a theoretical scaling followed by empirical adjustments. The method further involves the efficient computation and combining of metrics that are used to minimize the weighted error between candidate location solutions and the UTDOA and GPS measurements. This is done efficiently in two dimensions for UTDOA and in three dimensions for GPS measurements by increasing the complexity of searching operations as the optimal location solution is approached. A technique is also described that improves upon a particular location solution by changing the measurement weightings using criteria specific to GPS and UTDOA. | 02-18-2010 |
20100039326 | Variable Coherence Integration for the Location of Weak Signals - 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. | 02-18-2010 |
20100052990 | Portable, Iterative Geolocation of RF Emitters - Iterative geolocation of a stationary RF emitter through the use of TDOA may include the use of a single portable geolocation (e.g., TDOA) sensor, a pair of portable geolocation sensors and three of more portable geolocation sensors. Adding portable geolocation sensors to the iterative process reduces the constraints on the signals to be located as well as providing a reduction in the number of iterations required to obtain improved location accuracy. | 03-04-2010 |
20100120394 | Femto-Cell Location by Proxy Methods - Location of small, consumer deployed femto-cells cannot be determined by the usual site survey methods. Location of attached mobiles allows for a proxy location of the femto-cell that can then be used for wireless network planning including the provisioning of a calculated default emergency services location for the femto-cell. | 05-13-2010 |
20100120435 | Use of Radio Access Technology Diversity for Location - Various aspects are disclosed herein for determining a location estimate for multi-mode mobile devices using measurements from one or more radio access technologies and providing a combined location solution. Using the multiple radio access technology capability of the wireless communications system, a mobile communications device may be located on a first radio network characterized by a first radio modulation technique, radio network topology, and channel bandwidth. The mobile communications device may then be handed off to a second radio network and located using a second radio network characterized by a second radio modulation technique, radio network topology, and channel bandwidth. The two location estimates may then be used to develop a combined location estimate. | 05-13-2010 |
20100120447 | Femto-Cell Location by Direct Methods - Illustrative embodiments of the inventive subject matter described herein include, but are not limited to, the following: a femto-cell device, methods for use by a wireless location system (WLS) in locating a femto-cell device, and a wireless location system having certain features relating to the location of femto-cell devices. A femto-cell device used in a wireless communications system (WCS) includes a location subsystem configured to acquire information identifying the geographic location of the femto-cell device. The device also includes an antenna subsystem, a radio frequency (RF) block coupled to the antenna subsystem, a baseband block coupled to the RF block, and a communications block coupled to the baseband block. In addition, the device is configured to communicate with the WCS, including communicating at least some of the location information to the WCS. | 05-13-2010 |
20100227628 | Advanced Triggers for Location-Based Service Applications in a Wireless Location System - Methods and systems are employed by a wireless location system (WLS) for locating a wireless device operating in a geographic area served by a wireless communications system. An exemplary method includes monitoring a set of signaling links of the wireless communications system, and detecting at least one predefined signaling transaction occurring on at least one of the predefined signaling links. Then, in response to the detection of the at least one predefined network transaction, at least one predefined location service is triggered. | 09-09-2010 |
20100304763 | System for Automatically Determining Cell Transmitter Parameters to Facilitate the Location of Wireless Devices - Several techniques for locating wireless devices involve the Mobile Stations (MS) making measurements of the signals transmitted by geographically distributed base stations within a wireless network. If some key site information is known about these transmitters, such as the transmitter location, transmit signal power, signal propagation, and transmit signal timing, measurements of these transmit signals by a MS can be used to determine the position of the MS. An automatic method to detect transmitters, identify key transmitter information, and utilize the base station transmit signals to perform location is presented. In addition, this method facilitates the use of cell site transmit signals that are part of multiple wireless networks. | 12-02-2010 |
20110033002 | Location of Wideband OFDM Transmitters With Limited Receiver Bandwidth - One illustrative embodiment takes the form of a system for locating wireless transmitters employing an Orthogonal Frequency Division Multiplexing (OFDM) digital modulation scheme. The OFDM scheme comprises transmitting signal components over narrowband frequency channels spanning a wideband channel. The system includes a first receiving system configured to receive a fraction of the signal components transmitted by a first wireless transmitter to be located in a fraction of the narrowband frequency channels, and to process the fraction of the signal components to derive location related measurements. The system further includes at least a second receiving system configured to receive the fraction of the signal components transmitted by the first wireless transmitter, and to process this fraction of the signal components to derive location related measurements. The system also includes a processing system configured to use location related measurements from the first and second receiving systems to compute the location of the wireless transmitter. | 02-10-2011 |
20110134240 | Multi-Sensor Location and Identification - By combining imaging systems with wireless location functionality, a subject's videometric signature can be linked to a public identity, thus enabling continuous surveillance outside or between the coverage area of video surveillance networks. In addition to extending the surveillance coverage area, the combination of computerized video surveillance with wireless location determination may also allow for identification of mobile device users via the existing mobile equipment and user identifiers used in the wireless network. | 06-09-2011 |
20110148699 | Satellite Positioning Receiver and Proxy Location System - To reduce power consumption in a user terminal, especially mobile devices, a system and method are introduced that use terrestrial beacons as a location proxy when satellite positioning signals are not available. The geographic locations of the terrestrial beacons need not be known to use the beacons as a proxy for a satellite positioning signals derived location. | 06-23-2011 |
20110150211 | Passive System for Recovering Cryptography Keys - Modern cellular wireless communications providers strive to keep their network and subscribers secure through various means. The identity of the subscriber may be obfuscated through the use of a temporary identifier for most network transactions including signaling events, voice calls, SMS messages and data sessions. A subscriber's unique identity may only be transmitted over the air in an encrypted form. Similarly, the content of voice calls, SMS messages and data sessions may also be encrypted when transmitted over the air and even when transferred over internal network interfaces. However, the use of encryption presents significant challenges for law enforcement communities when court ordered lawful intercept is required to monitor and locate subscribers utilizing the wireless networks for illegal and/or terrorist purposes. A technique to aid in the determination of a subscriber's unique wireless identity and the decryption of encrypted signals would be very useful for lawful intercept. In this document we describe an architecture and technique to aid in the decryption of encrypted wireless signals for lawful intercept by determining the current encryption key. It may also be used to decrypt encrypted signals on internal interfaces of the wireless and wireline networks. | 06-23-2011 |
20120015670 | Hybrid GNSS and TDOA Wireless Location System - A method and apparatus for position determination is provided using measurements from both Global Positioning System (GPS) receivers and terrestrial-based Uplink Time Difference of Arrival (UTDOA) receivers. The method involves the transformation of downlink satellite measurements into equivalent UTDOA measurements by computing comparable cross-correlation coefficients and time differences of arrival with respect to a UTDOA reference station. The method includes a weighting operation whereby the relative weights of the UTDOA measurements and the relative weights of the GPS measurements are adjusted based on a theoretical scaling followed by empirical adjustments. The method further involves the efficient computation and combining of metrics that are used to minimize the weighted error between candidate location solutions and the UTDOA and GPS measurements. | 01-19-2012 |
20120020320 | Network-Based Location of Mobile Transmitters - In an overlay, network-based, wireless location system, LMUs typically co-located with BTSs are used to collect radio signaling both in the forward and reverse channels for use in TDOA and/or AOA positioning methods. Information broadcast from the radio network and by global satellite navigation system constellations can be received by the LMU and used to reduce the difficulty of initial system configuration and reconfiguration due to radio network changes. | 01-26-2012 |
20120082255 | Location of Wideband OFDM Transmitters with Limited Receiver Bandwidth - One embodiment takes the form of a system for locating wireless transmitters employing an Orthogonal Frequency Division Multiplexing (OFDM) digital modulation scheme, which comprises transmitting signal components over narrowband frequency channels spanning a wideband channel. The system includes a first receiving system configured to receive a fraction of the signal components transmitted by a first wireless transmitter to be located in a fraction of the narrowband frequency channels, and to process the fraction of the signal components to derive location related measurements. The system further includes at least a second receiving system configured to receive the fraction of the signal components transmitted by the first wireless transmitter, and to process this fraction of the signal components to derive location related measurements. | 04-05-2012 |
20120154218 | Position Estimation Through Iterative Inclusion of Measurement Data - In a wireless location system configured to use a baseline correlation method, an iterative approach to increasing location accuracy is disclosed. The quality of received signals is ordered from highest to lowest and used to calculate an initial location. The initial location is modified using the lower quality signals as constrained by the time and frequency deviation from the initial location and velocity estimate. | 06-21-2012 |
20120165037 | Robust Downlink Frame Synchronization Schemes in CDMA Wireless Networks for Geo-Location - A wireless location system is configured to operate in a CDMA-based wireless communication network. In exemplary embodiments, location measuring units (LMUs) can synchronize to sectors of base stations and store sector timing information. In response to a request to geo-locate a mobile device communicating with a sector, sector timing information for the servicing sector is sent to other LMUs and the LMUs can use the sector timing information to detect uplink signals transmitted by the mobile device. The location of the mobile device can then be estimated based on time of arrival measurements made by the LMUs. | 06-28-2012 |
20120167207 | Unauthorized Location Detection and Countermeasures - A location sentry system is provided for use within a mobile device. The sentry system can be configured to detect unauthorized attempts to locate mobile devices by monitoring messages passed between the mobile device and the wireless network and/or messages passed between components of the mobile device, and determining that one or more of the messages is/are indicative of an attempt to locate the mobile device. In response to a determination that an unauthorized attempt has been detected, the location sentry can be configured to take one or more actions. For example, the location sentry system could prevent location information from being sent back to the wireless network and/or the location sentry system could cause incorrect information to be sent to the wireless network. | 06-28-2012 |
20120194382 | Satellite Positioning Receiver and Proxy Location System - To reduce power consumption in a user terminal, especially mobile devices, a system and method are introduced that use terrestrial beacons as a location proxy when satellite positioning signals are not available. The geographic locations of the terrestrial beacons need not be known to use the beacons as a proxy for a satellite positioning signals derived location. | 08-02-2012 |
20130229936 | Network-Based Location of Mobile Transmitters - In an overlay, network-based, wireless location system, LMUs typically co-located with BTSs are used to collect radio signaling both in the forward and reverse channels for use in TDOA and/or AOA positioning methods. Information broadcast from the radio network and by global satellite navigation system constellations can be received by the LMU and used to reduce the difficulty of initial system configuration and reconfiguration due to radio network changes. | 09-05-2013 |
20130310070 | Advanced Triggers for Location-Based Service Applications in a Wireless Location System - Methods and systems are employed by a wireless location system (WLS) for locating a wireless device operating in a geographic area served by a wireless communications system. An exemplary method includes monitoring a set of signaling links of the wireless communications system, and detecting at least one predefined signaling transaction occurring on at least one of the predefined signaling links. Then, in response to the detection of the at least one predefined network transaction, at least one predefined location service is triggered. | 11-21-2013 |
20140059655 | Unauthorized Location Detection and Countermeasures - A location sentry system is provided for use within a mobile device. The sentry system can be configured to detect unauthorized attempts to locate mobile devices by monitoring messages passed between the mobile device and the wireless network and/or messages passed between components of the mobile device, and determining that one or more of the messages is/are indicative of an attempt to locate the mobile device. In response to a determination that an unauthorized attempt has been detected, the location sentry can be configured to take one or more actions. For example, the location sentry system could prevent location information from being sent back to the wireless network and/or the location sentry system could cause incorrect information to be sent to the wireless network. | 02-27-2014 |
20140342689 | Advanced Triggers for Location-Based Service Applications in a Wireless Location System - Methods and systems are employed by a wireless location system (WLS) for locating a wireless device operating in a geographic area served by a wireless communications system. An exemplary method includes monitoring a set of signaling links of the wireless communications system, and detecting at least one predefined signaling transaction occurring on at least one of the predefined signaling links. Then, in response to the detection of the at least one predefined network transaction, at least one predefined location service is triggered. | 11-20-2014 |
20140375505 | Positioning Using DTV Broadcast Signaling - For indoor location of a wireless device, use of Digital Television (DTV) signals for receiver location allows for high yield, precise location estimates. The device location is determined based on pseudo-ranges between the device and a plurality of DTV transmitters. The pseudo-ranges are determined based on the known and a priori unknown portions of the DTV signals received by the device and monitor stations. A new Payload Correlation Procedure (payload=unknown DTV data segments) to locate a client device is employed, and a Field Correlation Procedure, which uses only known data segments of the DTV signal, may be used in conjunction with the Payload Correlation Procedure. This approach addresses the problem presented by the limited size of the radio communications link between the Location Server and Client versus the very large bandwidth of multiple DTV channels. | 12-25-2014 |