Abstract: A method and apparatus for encoding information in a reference beacon signal for use in a time-difference-of-arrival/frequency-difference-of-arrival (TDOA/FDOA) geolocation system. Information is encoded in the reference beacon signal using variations in the times and frequencies of sequential reference signal transmissions. The encoded information may include an identifier associated with the transmitter of the reference beacon signal. A geolocation system receiving the reference beacon signal can thus differentiate it from non-cooperative target emissions as well as from other reference beacon signals.

Abstract: Systems and methods are provided for two-stage location. In one implementation, there is provided a method for receiving a first location of a first radio, the first radio providing the first location of the first radio; using the received first location to determine when to transmit an activation command from a portable locator to a second radio, the second radio coupled to the first radio; and receiving at the portable locator a beacon transmitted to enable the portable locator to precisely locate the second radio and the coupled first radio.

Abstract: Systems and methods are provided for two-stage location. In one implementation, there is provided a method for receiving a first location of a first radio, the first radio providing the first location of the first radio; using the received first location to determine when to transmit an activation command from a portable locator to a second radio, the second radio coupled to the first radio; and receiving at the portable locator a beacon transmitted to enable the portable locator to precisely locate the second radio and the coupled first radio.

Abstract: Methods and apparatus are described for a navigation system. A process includes providing a plurality of transmitters distributed throughout a desired coverage area; locking the plurality of transmitters to a common timing reference; transmitting a signal from each of the plurality of transmitters. An apparatus includes a plurality of transmitters distributed throughout a desired coverage area; wherein each of the plurality of transmitters comprises a packet generator; and wherein the plurality of transmitters are locked to a common timing reference.

Abstract: A navigation signal generator on a framework that provides a standardized object-oriented means for developing and managing signal processing functions. The framework provides the ability to dynamically reallocate functions allowing numerous communications, signals intelligence, and information warfare missions that may be required under a single platform and co-exist with other frameworks. In one embodiment the system is a software defined navigation augmentation using the software defined radio architecture.

Abstract: An optical subscriber system according to the present invention has an adaptive antenna having a plurality of antenna elements, for controlling the weighting on the antenna elements thereby to radiate beams that are adapted to radio wave environments, a position estimator for estimating the position of a mobile unit, a beam combiner for weighting signals received from the mobile unit by the antenna elements and combining beams, and a weighting coefficient generator for correcting weighting coefficients adapted to radio wave environments, which give initial weights as weights to form nulls in bearings other than the mobile unit based on the position of the mobile unit which has been estimated by the position estimator, for thereby reducing a time required for convergence.

Abstract: A GPS positioning system having a remote node and a network-aided GPS node locator. The remote node samples a GPS signal and transmits the GPS signal samples through a communication network having an intermediate node. The GPS node locator receives the GPS signal samples through the communication network, geolocates the intermediate node from a node ID, and uses the GNSS signal samples with the intermediate node geographical location for determining the geographical location of the remote node.

Abstract: To reduce interference and increase battery life, a method and apparatus for transmitting location data within an ad-hoc communication system is provided herein. During operation, a portion of a beacon payload is reserved to broadcast location information (coordinates) for a node as well as other parameters that may be needed for location estimation. In addition to a node's location, an accuracy of the nodes location is also included within the beacon field. Because nodes will no longer have to awake outside their beacon transmit times to broadcast location information, battery life is extended. In addition, because nodes will no longer be transmitting location information outside their guaranteed time slot, system interference is also reduced.

Abstract: A “synchrolite” or rebroadcasting device allows GPS or GNSS navigation signals received at one or several locations to be processed at a separate location. The signals received by the synchrolite are added to a pilot tone and then encoded with a superimposed spread-spectrum code before being rebroadcast. The superimposed code allows signals from different synchrolites to be distinguished during the navigation process.

Abstract: The invention relates to a transmitter identification system, which utilizes an identification signal embedded into a digital television signal, enabling the transmitter of origin to be identified at a receiving station. Ideally the identification signal is an orthogonal pseudo-random sequence time synchronized to the signal frame structure of the digital television signal. Particularly designed for single frequency networks, identification of the various transmitted signals enables the network to be tuned to eliminate or minimize multi-path effects at certain locations, which receive transmissions from various transmitters.

Abstract: Apparatus and method for resolving repeater location ambiguities in a CDMA network using a CDMA Time Pseudolite. The CDMA Time Pseudolite includes a CDMA receiver to receive a CDMA signal with an embedded CDMA timing, a baseband processor to extract the CDMA timing and to adjust the CDMA timing to derive a signal with GNSS-like timing; and a GNSS transmitter to generate a GNSS-like signal and to transmit the GNSS-like signal to a mobile station. In one embodiment, the CDMA Time Pseudolite is situated at or nearby a CDMA signal repeater so that a mobile station may unambiguously identify a received CDMA signal as being transmitted by a particular CDMA signal repeater and then using that received CDMA signal for position determination of the mobile station.

Abstract: A system and method for monitoring location based service emitter infrastructure. Beacon data is stored, the beacon data transmitted by beacons in an area and detected by a client device that is moved along a path at the location. The beacon data along the path of the client device is analyzed to determine whether any of the detected beacons have failed.

Abstract: A system for the relative navigation of aircraft and spacecraft is disclosed which uses a series of short duration, unmodulated radio pulses transmitted from a phased array antenna. The aircraft or spacecraft whose position is to be determined from another is called as the local station, whereas the other craft with the phased array antenna system is called as the transmitting station. The local station transmits a radio query pulse to the transmitting station. In response to the radio query pulse, the transmitting station transmits a series of unmodulated radio pulses, where each radio pulse is transmitted with a three dimensional radiation pattern that is different than the three dimensional radiation patterns of the other radio pulses transmitted by the transmitting station.

Abstract: Disclosed is radio monitoring apparatus which includes a radio station distinction unit, a direction measurement unit, a transmission source location estimation unit and a transmission source location classification unit. The radio station distinction unit outputs radio station distinction information for uniquely discriminating a radio station that is a transmission source of a transmitted signal from a received signal. The direction measurement unit measures an arrival direction of the transmitted signal. The transmission source location estimation unit estimates a location of the transmission source from results of the direction measurement and outputs an estimated location as transmission source location information. The transmission source location classification unit relates the radio station distinction information and the transmission source location information and outputs them.

Abstract: A first transceiver (4, 30) can position itself by forming an ad hoc network (20) of transceivers which assist the first transceiver in acquiring its position. A dedicated infrastructure such as GPS satellites is not required. The first transceiver (4, 30), once it has acquired its position, can be involved in a network (20) by another transceiver (32, 34, 36, 38, 40) to assist in the positioning of that transceiver. The acquisition of the position may involve factors such as the trustworthiness of the transceivers in the network and/or the positions of transceivers with which the first transceiver cannot directly communicate.

Abstract: An emergency evacuation guiding system for guiding people to run away in a building system as an accident occurs comprises a detector system for detecting an accidents which is occurred in the building system; an informing system for informing people that an accident occurs; a receiving system for receiving wireless signals from the informing system so as to know the message about the occurring of an accident; a guiding system for guiding people to run away from an accident area to a safety place; the guiding system including the at least one transmitter of the informing system and at least one receiver of the receiving system. The guiding system guides people to run out of the accident area by using the strength of the received signal in the receiver. The receiving system including at least one wireless receiver for detecting the strengths of the signals transmitted from the transmitter to the receiver.

Abstract: A detection system includes a fixed-position transmitter and a mobile unit. The transmitter digitally transmits a data packet including angle information associated with the transmitter, and the mobile unit includes a receiver for receiving the transmitted data packet. The mobile unit is configured to detect a plurality of data packets from a single transmitter, the plurality of data packets including non-identical angle information. The mobile also determines new angle information from the non-identical angle information in the plurality of data packets and determines a location of the mobile unit relative to the transmitter using the new angle information. Also, the mobile unit is configured to indicate information associated with the determined location to a user.

Abstract: A method of increasing the accuracy of geographical information of a mobile station of a radio communication system is described. The geographical information of the mobile station is evaluated without using a GPS receiver. Stored positions of other mobile stations using GPS receivers, are used to adapt the geographical information.

Abstract: The pseudolite includes a communication (COM) satellite receiver for receiving a communication satellite specific RF signal from a communication satellite and providing communication satellite navigation and position data. A GNSS receiver receives a GNSS signal from a GNSS satellite and provides GNSS timing information. A pseudolite transmitter receives the communication satellite navigation and position data and the GNSS timing information. The pseudolite transmitter includes at least one digital signal generator for utilizing the communication satellite navigation and position data and the GNSS timing information for providing a digital signal generator output having an intermediate frequency and navigation message data which are suitable for up-conversion to a desired communication channel RF frequency.

Abstract: A first transceiver can position itself by forming an ad hoc network of transceivers which assist the first transceiver in acquiring its position. A dedicated infrastructure such as GPS satellites is not required. The first transceiver, once it has acquired its position, can be involved in a network by another transceiver to assist in the positioning of that transceiver. The acquisition of the position may involve factors such as the trustworthiness of the transceivers in the network and/or the positions of transceivers with which the first transceiver cannot directly communicate.

Abstract: The present invention relates to an omnidirectional base station antenna arrangement with a number of antenna elements and a number of transceiver means for transmitting and receiving signals to/from a number of user stations. A feeding network is provided which comprises a number of phase ports, a number of which form first phase ports connected to a number of transceiver means for downlink communication and a number of which form second phase ports connected to a number of transceiver means for uplink communication. The feeding network comprises a number of antenna ports connected to antenna elements and the feeding network generates substantially independent, orthogonal signals to provide for phase diversity and the antenna elements are arranged to form at least one cylindrical array antenna.

Abstract: Navigation apparatus that may include a radio receiver, at least one directional antenna communicatively coupled to the radio receiver, and a navigation computer including a memory and a processor. The navigation computer may be communicatively coupled to the radio receiver to receive relative bearing information from the directional antenna to a set of known radio transmitters, such as (but not limited to) commercial broadcast radio or television stations. Using a database stored in the memory that includes a record of position information and a record of radio frequency information for the set of known radio transmitters, the apparatus allows for the calculation of one or more reference positions using relative bearing information to the set of known radio transmitters and the stored, known positions of the set of known radio transmitters.

Abstract: A system for determining the position of an object, comprising a reference transmitter device (202) disposed in a fixed position, the reference transmitter device (202) having a reference time supplying means for supplying a reference time signal that indicates a reference time, at least two transmitter/receiver devices (302) disposed in fixed positions with respect to each other and to the reference transmitter device (202), each transmitter/receiver device (302) having a time supplying means for supplying a time signal indicating a time, a receiver means for receiving the reference time signal from the reference transmitter device (202) and a synchronization means for processing the time signal and the reference time signal, as well as a position determining device (502) on the object for determining the position of the object.

Abstract: A reception high-frequency unit receives a GPS signal transmitted from a satellite configuring GPS. A signal generation unit generates a plurality of pseudo random noise codes that are used for the positioning operation by a positioning apparatus for implementing a positioning operation based on the GPS signal and that are in the same form as that of the GPS signal. A transmission high-frequency unit generates and transmits based on the pseudo random noise codes, a positioning signal in the same form as that of the GPS signal. A transmission control unit controls the transmission high-frequency unit in such a way that a time difference based on the GPS signal received by the reception high-frequency unit is assigned to each positioning signal and the thus-assigned positioning signal is transmitted.

Abstract: Apparatus and methods for resolving integer ambiguities in position determination. An embodiment of the invention includes a reference system, augmented with multi-frequency pseudolites using a carrier phase differential GPS implementation, and a mobile system. In one embodiment, the components of the reference system includes one or more multi-frequency pseudolites, one or more multi-frequency reference receivers, a data link standing alone or built into the pseudolites, and the associated antennae for each of these elements. The components of the reference system may be stationary. The mobile system may include a multi-frequency receiver and its associated antennae. Because the mobile systems may passively receive information, an unlimited number of mobile systems may be included in any given embodiment of the invention.

Abstract: A search and rescue beacon includes a main transmitter transmitting a Cospas-Sarsat signal at a main frequency and an auxiliary homing transmitter transmitting a homing signal at a homing frequency close to the main frequency. Advantageously both the Cospas-Sarsat signal and the homing signal are generated by a single synthesizer switching between a main Cospas-Sarsat burst transmission and a continuous homing frequency transmission of the homing signal. The Cospas-Sarsat signal is advantageously transmitted at a higher power than the homing signal. The single synthesizer may use a single amplifier chain. The single synthesizer and amplifier chain may use a single antenna.

Abstract: The invention relates to a method of transmitting a synchronized channel in a radio transmitter and to a radio transmitter. The method comprises transmitting normal radio bursts on a normal channel asynchronously. In the invention, synchronized timing is obtained, synchronized radio bursts (SB) are formed, and a synchronized radio burst is transmitted in the place of a normal radio burst (NB). The length of the synchronized radio burst (SB) is at most half of the length of the normal radio burst (NB). The transmission of the synchronized radio burst (SB) is in synchronization with the obtained synchronized timing.

Abstract: Methods, devices and systems for WLAN communication are described. Intercell interference between overlapping WLAN cells is mitigated by a combination of frequency reuse, code division and time resource negotiation. Information used for time resource negotiation can be broadcast via beacon signal or communicated via a wireline backbone system which interconnects access points.

Abstract: A method for operating an autonomous vehicle at an airport comprises the steps of: receiving a set of general purpose navigation signals; receiving a supplementary set of navigation signals; receiving constraint data representing a permitted area of operation; calculating a present position of the vehicle; comparing the calculated present position of the vehicle with the constraint data, thereby to determine whether the vehicle's present position lies within the permitted area; and producing a signal indicative of the result of said comparing step. The autonomous vehicle for use at an airport, comprising: a navigation processor for calculating a present position of the vehicle; a constraint store for storing constraint data indicating a permitted area of operation; navigation receivers for receiving general purpose navigation signals and supplementary navigation signals, for guiding aircraft to land at the airport; and a comparator for comparing the constraint data with the present position.

Abstract: A method, apparatus, and computer-readable media comprise receiving a broadcast digital television signal comprising data relevant to one or more particular locations; generating a pseudorange based on the broadcast digital television signal; and determining location of an apparatus based on the pseudorange and a location of a transmitter of the broadcast digital television signal, and selecting a portion of the data relevant to the one or more particular locations based on the determined location of the apparatus.

Abstract: A system, method and computer program product for positioning pulses, including positioning pulses within a specified time layout according to one or more codes to produce a pulse train having one or more predefined spectral characteristics where a difference in time position between adjacent pulses positioned to produce a spectral characteristic differs from another difference in time position between other adjacent pulses positioned to produce the spectral characteristic. The present invention may include shaping a code spectrum according to a spectral template in order to preserve a pre-defined code characteristic. A pre-defined code characteristic can include desirable correlation, or spectral properties. A transmitter incorporating the present invention can avoid transmitting at a particular frequency. Similarly, a receiver can avoid interference with a signal transmitting at a particular frequency. A radar system, can avoid a radar jammer attempting to jam a particular frequency.

Abstract: A real-time path-directed controller for navigating an object along a desired path is disclosed. The controller comprises: a position sensor which contributes to the production of a conditioned object position signal to a controller summer; a heading conditioning module which contributes to the production of a conditioned heading signal to the controller summer; a control apparatus sensor which contributes to the production of a conditioned control apparatus signal to the controller summer; and a control apparatus null position conditioning module which contributes to the production of a conditioned null position signal to the controller summer. The controller summer sums the signals to produce a controller summer signal to a controller summer conditioning module so as to produce a control apparatus control signal to a control apparatus controller so as to direct the control apparatus and thereby direct the object by feedback control along the desired path.

Abstract: Systems and techniques for location determination. A plurality of tags emitting radio frequency signals are dispersed throughout a region, such as a building, within which a user's location is to be determined. The radio frequency signals emitted by the tags include information that can be used to identify the location in which the tags axe placed, or simply to distinguish the tags from one another. A portable device receives signals from the tags and provides the signal information to a location server that computes the location of the portable device by comparing the signal information received from the portable device to a map of location venus stored signal information, and identifies the location of the portable device as the location for which the stored signal information best matches the signal information received from the portable device.

Abstract: The invention relates to a method for estimating the position of a receiver receiving code modulated signals from at least one beacon. The method comprises delimiting a region containing the receiver position based on a code modulated signal received at the receiver from at least one beacon and on available information including at least an initial information on the receiver position. The method further comprises estimating the receiver position as a position within the delimited region which minimizes an error criterion. The invention relates equally to such a receiver, to a system comprising such a receiver and to a corresponding software program product enabling an estimation of the position of a receiver.

Abstract: Apparatus and methods for resolving integer ambiguities in position determination. An embodiment of the invention includes a reference system, augmented with multi-frequency pseudolites using a carrier phase differential GPS implementation, and a mobile system. In one embodiment, the components of the reference system includes one or more multi-frequency pseudolites, one or more multi-frequency reference receivers, a data link standing alone or built into the pseudolites, and the associated antennae for each of these elements. The components of the reference system may be stationary. The mobile system may include a multi-frequency receiver and its associated antennae. Because the mobile systems may passively receive information, an unlimited number of mobile systems may be included in any given embodiment of the invention.

Abstract: The design of the low cost GPS/IMU positioning and data integrating method, which employs integrated global positioning system/inertial measurement unit enhanced with dual antenna GPS carrier phase measurements to initialize and stabilize the azimuth of the low cost GPS/IMU integrated system, is performed. The utilization of the raw carrier phase measurement for the integration speeds up the ambiguity search.

Abstract: A method and system for location-determination of a mobile comprising of a receiver with a variable processor gain of up to 45.15 dB for detecting signals transmitted from transmitters that at a farther distance as well as from transmitters that are situated in sparsely populated areas. The system also includes a plurality of terrestrially deployed transmitters known as “pseudolites” that broadcast GPS-like signals, and in addition implementing the use of existing, available information from modulated signals, such as phase, amplitude and convolution with pseudorandom codes.

Abstract: An apparatus, method, and computer-readable media comprise a receiver adapted to receive a plurality of broadcast signals; a signal processor adapted to determine a position based on the received plurality of broadcast signals; a signal generator adapted to generate a ranging signal comprising a known component of a television signal; and a transmitter adapted to broadcast a signal comprising the ranging signal and a position signal comprising a description of the position.

Abstract: The invention relates to a method and to devices for determining in a positioning system the time of reception of a beacon signal which was received and tracked by a receiver. In order to enable a re-acquisition of the system time based on a noisy received signal, it is proposed that the method comprises as a first step reconstructing a beacon signal for an interval based on available information. Then, a cross-correlation is performed between the reconstructed signal and the received signal at different relative positions to each other. Next, the time of transmission of the received signal is determined based on information for the reconstructed signal and on the relative position resulting in the maximum correlation value. Finally, a time of reception of said received signal is determined as the sum of the determined time of transmission of the received signal and of a calculated time of flight of the received signal.

Abstract: A method of increasing the accuracy of geographical information of a mobile station of a radio communication system is described. The geographical information of the mobile station is evaluated without using a GPS receiver. Stored positions of other mobile stations using GPS receivers, are used to adapt the geographical information.

Abstract: A location determination apparatus, method and system (10, 23, 26, 32, 36, 48, 52, 60, 64, 74, 78, 84, 90, 106) that is an improvement upon existing location determining techniques. The invention enables precision indoor location determination through the use of non-DTV terrestrial broadcast signals (e.g. one way, wide area, dissemination of information)(20), or re-broadcast signals (44, 56, 70, 80) of the proposed (terrestrial based) digital satellite radio relay transmitters (42, 54) to provide position location. This solution does not require a local receiver to correct for long distance propagation dispersion, particularly for the satellite relay, as the digital radio satellites are already synchronized to GPS time.

Abstract: A geographic-based communications service system has a mobile unit for transmitting/receiving information, and access points connected to a network. The access points are arranged in a known geographic locations and transmit and receive information from the mobile unit. When one of the access points detects the presence of the mobile unit, it sends a signal to the network indicating the location of the mobile unit and the information requested by the mobile unit. Based on the signal received from the access point, the network communicates with information providers connected to the network and provides data to the mobile unit through the access point corresponding to the location of the mobile unit.

Abstract: A GPS microphone, which is adapted for incorporating a communication system, includes a speaker-microphone set, a radio frequency transmitter communicatively networked with the communication system through radio frequency signals, and a GPS controller electrically connected with the radio frequency transmitter to encode a positioning data into a RF positioning signal in form of audio signal wherein when the GPS controller is triggered, the radio frequency transmitter is activated to transmit RF positioning signal to the communication system.

Abstract: A process to determine the impact location of a transmitter-bearing object which is released for tracking purposes or to hit a target within a geographical area, wherein data obtained from the impact location can be used to determine the relation of the impact location and the target.

Abstract: A method and cellular telecommunication apparatus for displaying the local time. The apparatus is provided with an internal clock, which indicates time in at least hours and minutes. The apparatus is also provided with display means for displaying time, and control means for calculating the local time based on information about local time data. Upon activation of the apparatus, it establishes a wireless connection to a cellular network, wherein the time is displayed on the display means. The apparatus sends a request to the network, which comprises a question about local time data. In response to the request, the network sends a response back to the apparatus. The response comprises information about local time data. The control means calculates the time difference between the internal clock and the local time data, and changes the indication of hours in the display means based on the time difference.

Abstract: A method and apparatus for determining a desired position of a pseudolite at a site. The method and apparatus includes predicting an area of coverage of the site by at least one GPS satellite, determining a condition of reduced coverage as a function of the predicted area of coverage, displaying the area having reduced coverage on a terrain map, and placing a pseudolite at a location at the site to provide coverage in the area having reduced coverage.

Abstract: A transceiver is provided that can adapt itself to operate as an RF tag reader or as a bluetooth transceiver by changing its reception and transmission capabilities. The cost and area of an additional transceiver where both a bluetooth transceiver and an RF tag reader are required is avoided. The same radio part is used for both bluetooth and for RF tag reader operation. Since the operation band is the same, there is no need to change the center frequency of the resonance needed by the radio front-end. Software controlled adaptivity is included due to the different nature of these systems so that the mode of the radio hardware can be programmed easily and on the fly. This provides a software defined architecture tailored for bluetooth/RF tag operation. This invention integrates two different systems to one transceiver chip giving cost and space savings by reusing existing analog parts.

Abstract: Method for transferring information between a vehicle and a transmitter in which a unique pseudorandom noise signal is transmitted by the transmitter in a carrier-less fashion composed of frequencies within a pre-selected band. Information is encoded in the noise signal relating to an identification of the transmitter and a position of the transmitter and the vehicle is provided with a device for extracting the information from the noise signal. The code to use for encoding the noise signal may be selected based on the position of the transmitter so that analysis of the code, or a portion thereof, provides an indication of the position of the transmitter. Information about accidents, weather conditions, road conditions, map data and traffic control devices and about errors in a GPS signal can also be encoded in the noise signals.

Abstract: Techniques for location determination are described. A plurality of tags emitting radio frequency signals are dispersed throughout an region, such as a building, within which a user's location is to be determined. The radio frequency signals emitted by the tags include information that can be used to identify the location in which the tags are placed, or simply to distinguish the tags from one another. A portable device receives signals from the tags and provides the signal information to a location server that computes the location of the portable device by comparing the signal information received from the portable device to a map of location versus stored signal information, and identifies the location of the portable device as the location for which the stored signal information best matches the signal information received from the portable device.

Abstract: Positioning system for locating a mobile body comprising a plurality of earth based spread spectrum (SS) broadcasting stations arranged geographically in a cellular pattern. Each SS broadcasting station include a modulator providing a channel signal structure which is substantially orthogonal with respect to adjacent stations in the cellular pattern, each channel signal including navigation beacon data including a unique beacon identification, station latitude and longitude, time_slot and phase characterizations and selected parameters of adjacent stations. In one embodiment, each modulator provides a chirped SS signal in which the navigation beacon is a frequency tone that is repeatedly swept over a selected frequency band for each station. In a further embodiment, each modulator provides a GPS like direct sequence SS signal in which the navigation beacon is a PN coded broadcast.