Abstract: Replica correlation processing, and associated representative signal-data reduction and reconstruction techniques, are used to detect signals of interest and obtain robust measures of received-signal parameters, such as time differences of signal arrival and directional angles of arrival, that can be used to estimate the location of a cellularized-communications signal source. The new use in the present invention of signal-correlation processing for locating communications transmitters. This enables accurate and efficient extraction of parameters for a particular signal even in a frequency band that contains multiple received transmissions, such as occurs with code-division-multiple-access (CDMA) communications.

Abstract: Ground-based pseudolites support accurate determination of mobile receiver locations by broadcasting CDMA signals interleaved by a TDMA system. Pseudolites synchronize signal transmissions with an accurate timing reference, such as can be derived from GPS satellites. Adjacent pseudolites broadcast CDMA signals at different times, eliminating near-far signal interference between pseudolites. A mobile receiver, typically a cellular telephone, receives and enables determination of times of arrival (TOA) of the pseudolite signals. A location processor associated with the mobile receiver may access an internal database of pseudolite locations, or pseudolite location information may be encoded in pseudolite transmissions. The location processor uses pseudolite location information and TOA to determine mobile receiver location. The TDMA pseudolite-based system may augment the GPS to provide more accurate location information than is available from the GPS alone.

Abstract: Replica correlation processing, and associated representative signal-data reduction and reconstruction techniques, are used to detect signals of interest and obtain robust measures of received-signal parameters, such as time differences of signal arrival and directional angles of arrival, that can be used to estimate the location of a cellularized-communications signal source. The new use in the present invention of signal-correlation processing for locating communications transmitters. This enables accurate and efficient extraction of parameters for a particular signal even in a frequency band that contains multiple received transmissions, such as occurs with code-division-multiple-access (CDMA) communications.

Abstract: Replica correlation processing, and associated representative signal-data reduction and reconstruction techniques, are used to detect signals of interest and obtain robust measures of received-signal parameters, such as time differences of signal arrival and directional angles of arrival, that can be used to estimate the location of a cellularized-communications signal source. The new use in the present invention of signal-correlation processing for locating communications transmitters. This enables accurate and efficient extraction of parameters for a particular signal even in a frequency band that contains multiple received transmissions, such as occurs with code-division-multiple-access (CDMA) communications.

Abstract: The present invention combines the measured characteristics of a radio signal in a communications environment with collateral information to produce an accurate and economical way to locate a mobile transmitter station, such as a mobile telephone, in a cellular telephone network.

Abstract: An apparatus and method for combining the measured characteristics of a radio signal in a communications environment with collateral information to produce an accurate and economical way to locate a mobile transmitter station, such as a mobile telephone, in a cellular telephone network.

Abstract: A system and method for locating a mobile transceiver relative to plural fixed sensor stations. The system includes plural sensor stations that receive a signal transmitted by the mobile transceiver. A probable position of the mobile transceiver is determined based on a time of arrival of the signal and an angle of arrival of the signal received at the plural sensor stations.

Abstract: A method and apparatus for locating a mobile radio communications transceiver in a cellular-telephone or cellular-like communications system use a simplified system for passive monitoring of the signals emitted by the transceiver. Two receiving base stations can determine the timing of signal arrivals from the remote transceiver. This timing information is then combined with collateral, position-sensitive information to determine the likely location of the transceiver. The present invention has particular applicability to roadway transportation in that it facilitates enhanced emergency services and roadside assistance in response to calls for assistance, and it permits the passive monitoring of traffic flow.

Abstract: Ground-based pseudolites support accurate determination of mobile receiver locations by broadcasting CDMA signals interleaved by a TDMA system. Pseudolites synchronize signal transmissions with an accurate timing reference, such as can be derived from GPS satellites. Adjacent pseudolites broadcast CDMA signals at different times, eliminating near-far signal interference between pseudolites. A mobile receiver, typically a cellular telephone, receives and enables determination of times of arrival (TOA) of the pseudolite signals. A location processor associated with the mobile receiver may access an internal database of pseudolite locations, or pseudolite location information may be encoded in pseudolite transmissions. The location processor uses pseudolite location information and TOA to determine mobile receiver location. The TDMA pseudolite-based system may augment the GPS to provide more accurate location information than is available from the GPS alone.

Abstract: Replica correlation processing, and associated representative signal-data reduction and reconstruction techniques, are used to detect signals of interest and obtain robust measures of received-signal parameters, such as time differences of signal arrival and directional angles of arrival, that can be used to estimate the location of a cellularized-communications signal source. The new use in the present invention of signal-correlation processing for locating communications transmitters. This enables accurate and efficient extraction of parameters for a particular signal even in a frequency band that contains multiple received transmissions, such as occurs with code-division-multiple-access (CDMA) communications.

Abstract: A method and apparatus for locating a mobile radio communications transceiver in a cellular-telephone or cell-like communications system uses a simplified system for passive monitoring of the signals emitted by the transceiver. A single base station can determine a line of bearing to the remote transceiver. This line of bearing is then combined with collateral, position-sensitive information to determine the likely location of the transceiver. The present invention has particular applicability to roadway transportation in that it facilitates enhanced emergency (9-1-1) services and roadside assistance in response to calls for assistance, and it permits the passive monitoring of traffic flow.