Abstract: A system for locating an object within a monitored environment includes a tag transmitter that transmits an RF signal to receivers having unsynchronized clocks. A processor is operative with each receiver and determines clock timing relationships for the clocks based on one of at least propagation or processing delays in the receivers to synchronize receiver performance.

Abstract: A system for locating an object within a monitored environment includes receivers arranged in loosely coupled networks. A tag transmitter acts as a network node and bridge between the loosely coupled networks. A processor is operative with each receiver within each network for defining a clock timing for each network, a system time for all networks, and tracking its relationship to the clock timing for each network for time synchronizing all receivers. The processor is also operative for conducting differentiation of time of arrival signals received from a tag transmitter to locate an object associated with the tag transmitter.

Abstract: A wireless local area network and location system for locating objects within a monitored environment are disclosed. A plurality of access point stations receive and transmit communication signals within a wireless local area network. A processor is operatively connected to each of the access point stations and operative for processing communication signals received from the mobile station and, in one embodiment, determining which communication signals are first-to-arrive signals and conducting differentiation of the first-to-arrive signals to locate a mobile station. Delayed versions of at least one interference signal are weighted and the amplitude and phase controlled with weighted functions W1, W2 . . . Wn. The resultant weighted replicas are summed to determine an approximation of disbursed interference for cancelling interference. The location system can include a tag transmitter and spaced monitoring receivers and processor.

Abstract: An object tracking system for locating radio-tagged objects within a monitored environment has a plurality tag transmission readers that detect RF transmissions from the tags, and generate output signals representative of the time-of-arrival of first-to-arrive tag transmissions. An object location processor processes the first to arrive signals in accordance with a multilateration algorithm to geolocate a tag. In order to modify the operation of a tag that comes within a prescribed region of the monitored environment (such as passing through a doorway), one or more relatively short range, magnetic field proximity-based, tag-programming ‘pingers’, are placed proximate to the region. A magnetic field receiver on the tag detects the field generated by the pinger and causes the tag to change operation such as increase its RF transmission rate.

Abstract: A vehicle tag includes a housing and a tag connector supported by the housing for connecting to a diagnostic jack of a vehicle on-board diagnostic (OBD) system. A tag transmitter is carried by the housing and operative with the tag connector for receiving telemetry data from the OBD system and transmitting the telemetry data in an RF pulse.

Abstract: Magnetic field-based communication with an object is enhanced by generating a rotating AC magnetic field that effectively ensures magnetic field coupling with the magnetic field sensor of the object, irrespective of the orientation of the object. The rotating AC magnetic field is produced by a diverse spatial orientation (a two-dimensional arrangement) of a plurality of magnetic field coils, and the driving of those coils in a prescribed phase relationship (e.g., in phase quadrature) to realize a composite AC magnetic field that rotates (at the carrier frequency of the coil drive signal) over the entirety of the spatial coverage area.

Abstract: Magnetic field-based communication with an object is enhanced by generating a rotating AC magnetic field that effectively ensures magnetic field coupling with the magnetic field sensor of the object, irrespective of the orientation of the object. The rotating AC magnetic field is produced by a diverse spatial orientation (a two-dimensional arrangement) of a plurality of magnetic field coils, and the driving of those coils in a prescribed phase relationship (e.g., in phase quadrature) to realize a composite AC magnetic field that rotates (at the carrier frequency of the coil drive signal) over the entirety of the spatial coverage area.

Abstract: An amplitude modulation (AM) based mechanism controllably alters the shape of a binary phase shift keyed (BPSK) digital spreading waveform modulated onto an RF carrier. The modulated RF carrier is amplified by a saturated RF amplifier. The spectral properties of the amplified AM-BPSK waveform, when combined with the spectral properties of a BPSK waveform modulated onto the RF carrier and amplified by another saturated RF amplifier, produces a composite BPSK-modulated RF waveform containing substantially suppressed sidelobes.

Abstract: A system and method for locating an object uses a plurality of tag signal readers that receive wireless tag signals from a tag transmitter coupled with an object to be located. The tag signals include data indicating the identity of the object to which the tag transmitter is coupled. Each tag signal reader includes a global positioning system receiver associated therewith for determining the location of a tag signal reader. A wireless transmitter transmits a wireless data signal incorporating the wireless tag signal and location of the tag signal reader to a location processor, which receives the wireless data signals and determines which tag signals are first-to-arrive signals and conducts differentiation of the first-to-arrive signals to locate a tag transmitter and object coupled therewith.

Abstract: A system and method for identifying objects within a monitored environment includes a plurality of tag signal readers contained within the monitored environment and serially connected along a single connection line as a coaxial cable for receiving tag signals from at least one tag contained within the monitored environment. The tagged signals received by tag signal readers are timed and associated with a particular tag signal reader, such as by the use of multiplexing techniques. A location processor is connected to the single connection line and determines which tag signals are first-to-arrive signals and conduct differentiation of the first-to-arrive signals to locate a tag.

Abstract: A time division multiplexed reader to shared RF channel processor signal transport network for a geolocation system in which the number of readers is relatively small, allowing the use of only a single shared RF channel processor. The differential signal transport delays among respective segments of the network creates an inherent set of time division multiplexed time slots for the various readers, that allows the shared RF channel processor to receive and process the output of each reader in a known, independent time frame.

Abstract: A tool for augmenting and customizing business transaction processes uses the communication capability and functionality of a geolocation system to embed information associated with a transaction of a tagged object within the spread spectrum signals used to geolocate the object. This enables an ancillary transaction controller, separate from the geolocation system, to focus or target one or more transactions with respect to the tagged object, which may be an individual, such as a customer, patient, client, or the like of an institution in which the geolocation system is installed.

Abstract: A system and method for locating an object uses a plurality of tag signal readers that receive wireless tag signals from a tag transmitter coupled with an object to be located. The tag signals include data indicating the identity of the object to which the tag transmitter is coupled. Each tag signal reader includes a global positioning system receiver associated therewith for determining the location of a tag signal reader. A wireless transmitter transmits a wireless data signal incorporating the wireless tag signal and location of the tag signal reader to a location processor, which receives the wireless data signals and determines which tag signals are first-to-arrive signals and conducts differentiation of the first-to-arrive signals to locate a tag transmitter and object coupled therewith.

Abstract: An elapsed time clock is incorporated into a part call tag for requesting replenishment of components used by workstations of a manufacturing facility. One or more transmission readers spatially distributed around the manufacturing facility detect a part call signal transmitted from the part call tag. A reader output processing subsystem processes part call signals detected by at least one of the tag transmission readers to recover information contained in the part call signal. A management processor associates the recovered information with a respective workstation, and what component is to be replenished. The elapsed time clock is reset when the part call tag is operated to transmit a part call signal, and thereby serves as a call tag ‘stop watch’—informing workstation personnel of the length of time that has elapsed since the last part call transmission from that tag.

Abstract: A location system includes a plurality of signal readers for receiving signals from a wireless transmitter to be located. The signals include a wideband, spread spectrum signal and a timing marker appended a predetermined time in front of the wideband, spread spectrum signal for indicating the presence of the wideband, spread spectrum signal. A location processor is operatively coupled to the signal readers for detecting the timing markers of signals and responsive to a detection of a timing marker, correlating a signal as a first-to-arrive signal and conducting differentiation of first-to-arrive signals to locate a wireless transmitter.

Abstract: The unwanted influence a noise-source environment upon a modulated (e.g., FSK-encoded) magnetic field-based communication system is diminished by a non-modulated AC magnetic field communication scheme that uses a demodulatorless magnetic field detector. When installed in a tag to be tracked by a geolocation system, the demodulatorless detector responds when the tag comes within a prescribed proximity of the field generator producing the non-modulated AC magnetic field. The received signal is downconverted to baseband and processed to detect a valid AC magnetic field tone and indicate whether the tag is within a prescribed proximity of the AC magnetic field source.

Abstract: The unwanted influence a noise-source environment upon a modulated (e.g., FSK-encoded) magnetic field-based communication system is diminished by a non-modulated AC magnetic field communication scheme that uses a demodulatorless magnetic field detector. When installed in a tag to be tracked by a geolocation system, the demodulatorless detector responds when the tag comes within a prescribed proximity of the field generator producing the non-modulated AC magnetic field. The received signal is downconverted to baseband and processed to detect a valid AC magnetic field tone and indicate whether the tag is within a prescribed proximity of the AC magnetic field source.

Abstract: A system of the present invention is operative for locating a wireless mobile device in communication with a wireless local area network (WLAN) that includes a plurality of cells defining a wireless local area network each having an access point base station. The access point base stations communicate with wireless mobile devices using wireless communication signals as typically spread spectrum communication signals. A processor is operatively connected to each of the access point base stations and operative to process communication signals transmitted from a mobile device and determine which signals are first-to-arrive signals based on a common timing signal and conduct differentiation of the first-to-arrive signals to locate the mobile device.

Abstract: A communication system provides robust, short range radio communications between battery operated devices by using ON-OFF-KEYED (OOK) modulation and either frequency shift keyed (FSK) modulation or pulse position/width modulation (PPM/PWM), in combination with a prescribed communications protocol. The system transmitter requires no local oscillator and is only active during actual communication, so that its current drain is not a significant factor in total battery life. Also, the receiver is active for only a small fraction of time. The need for large, complex and expensive filters is minimized by using a single IF band-pass filter in active form or passively in the form of a low cost ceramic filter such as those used in inexpensive transistor radios. The digital transmitter and receiver portions of the system are implemented by low cost, and ultra low power CMOS logic.

Abstract: A system and method for identifying objects within a monitored environment includes a plurality of tag signal readers contained within the monitored environment and serially connected along a single connection line as a coaxial cable for receiving tag signals from at least one tag contained within the monitored environment. The tagged signals received by tag signal readers are timed and associated with a particular tag signal reader, such as by the use of multiplexing techniques. A location processor is connected to the single connection line and determines which tag signals are first-to-arrive signals and conduct differentiation of the first-to-arrive signals to locate a tag.