Abstract: A wireless location system may include geolocation of a wireless device connected to Voice-over-Internet-Protocol (VoIP) adapter. The VoIP adapter may include a wireless transceiver or a wireless location determining receiver that facilitates the location of a wireless device connected to the VoIP adapter. The wireless transceiver or the location determining receiver may provide location information to an emergency dispatcher.

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: 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.

Abstract: For Wireless Communications Networks (WCNs) that support soft handover, cooperator receiver selection for a TDOA, AOA, TDOA/AOA, or hybrid network-based or network-overlay Wireless Location System (WLS) must contend with one or more network base stations as a serving cell. When the active set contains more than one member, two techniques for determining a set of cooperating and demodulating receivers to use in the signal collection for location estimation is disclosed. In one embodiment, the active set members are constructively reduced to a single member that is used as a proxy serving cell. In another embodiment, the information contained in the active set membership is retained and a new set of demodulating and cooperator receivers are generated based on the entire membership of the active set.

Abstract: For Wireless Communications Networks (WCNs) that support soft handover, cooperator receiver selection for a TDOA, AOA, TDOA/AOA, or hybrid network-based or network-overlay Wireless Location System (WLS) must contend with one or more network base stations as a serving cell. When the active set contains more than one member, two techniques for determining a set of cooperating and demodulating receivers to use in the signal collection for location estimation is disclosed. In one embodiment, the active set members are constructively reduced to a single member that is used as a proxy serving cell. In another embodiment, the information contained in the active set membership is retained and a new set of demodulating and cooperator receivers are generated based on the entire membership of the active set.

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: 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.

Abstract: 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.

Abstract: A wireless location system may include geolocation of a wireless device connected to Voice-over-Internet-Protocol (VoIP) adapter. The VoIP adapter may include a wireless transceiver or a wireless location determining receiver that facilitates the location of a wireless device connected to the VoIP adapter. The wireless transceiver or the location determining receiver may provide location information to an emergency dispatcher.

Abstract: 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.

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: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

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.

Abstract: In a wireless location system, a method for determining frame and slot timing information for use in receiving an uplink signal from a user equipment (UE) device assigned to an uplink Dedicated Physical Control Channel (DPCCH) includes receiving signals in the uplink DPCCH at a location measurement unit (LMU) of the WLS. The method also includes detecting a predefined bit pattern known to be present in a plurality of predefined slots of the uplink DPCCH. Next, the frame and slot timing information are determined for the uplink DPCCH based on the detected bit pattern. Finally, the frame and slot timing information is used for collecting uplink signals from the UE for use in location processing.

Abstract: 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.

Abstract: 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.