Abstract: Apparatus provides information to a mobile user. The apparatus includes a mobile communications system having a fixed part and one or more mobile parts for communicating with the fixed part. The fixed part is adapted to receive one or more requests for user-specific information from the mobile part, and to provide the user with information relating to the or each request. Preferably the mobile user has access to permanent user-specific information and/or non-permanent user-specific information, and the mobile part is adapted to send said permanent user-specific information and/or non-permanent user-specific information to the fixed part.

Abstract: The invention relates to a receiver of a satellite positioning system.

Abstract: A GPS receiver (26) for processing GPS satellite signals and adapted for connection to a client device (24). The receiver (26) includes a down converter (44), a correlator (46), and a microcomputer A. The microcomputer A has a microprocessor A, a first memory (48A), a second memory (48B, 148B), and an input/output interface (50). The input/output interface (50) is capable of being connected to the client device (24). The first memory (48A) contains a first set of instructions for the microprocessor A to download and store in the second memory (48B, 148B) at least one time critical GPS software module (A1, A2, . . . AN) from the client device (24). The first memory (48A) also contains a second set of instructions for the microprocessor A to determine whether to download and store in the second memory (48B, 148B) a plurality of non-time critical software modules (B1, B2, . . . BN) from the client device (24).

Abstract: The present invention provides a method for determining synchronisation of a signal received in a global positioning system receiver and transmitted by a global positioning system satellite, wherein the method comprises the steps of transform coding (14) said received signal so as to transform said received signal from time domain to frequency domain coefficients, dividing respective (18) ones of said frequency domain coefficients by corresponding ones of transform coefficients of the expected transmitted signal associated with said satellite to provide corresponding transform value ratios, and deriving (20, 22) from respective transform value ratios corresponding scaled values of the time delay of the signal between the satellite and the receiver. The invention directs the search for synchronisation to a small set of chips thereby providing an indication of the identity of the synchronisation sequence.

Abstract: An adaptive antenna beamformer is presented, said beamformer including a first signal source 100 and a second signal source 102 and an ambient noise or other interfering signals source 106, which are exposed to an antenna array 104. The mixed signals 108 are provided to a blind source separation processor 110. The blind separation processor 110, in this case an Independent Component Analysis element, is comprised of a group of processes that are configured to separate mixtures of signals blindly. The blind separation processor 110, provides three outputs, a first signal output 112, a second signal output 114, and a third signal output 116. The signal outputs each correspond to their respective signal input.

Abstract: A vehicle information system which includes an in-vehicle system 105 and a centralized server system 120. The in-vehicle system communicates with the server system using a wireless communication link 110, such as over a cellular telephone system. A position system, such as a set of GPS satellites 140, provides positioning signals that are used by the in-vehicle systems, and optionally by the centralized server system to increase the accuracy of position estimates. In one version of the system, an operator specifies a destination to an in-vehicle system which validates the destination. The in-vehicle system transmits specification of the destination to a server system 125 at the centralized server. The server system computes a route to the destination and transmits the computed route to the in-vehicle system. The in-vehicle system guides the operator along the route.

Abstract: The invention relates to a diversity reception system for motor vehicles for digitally modulated terrestrial and/or satellite radio signals in the frequency range above 1 GHz. The system includes an antenna arrangement of which the reception signal is supplied to a radio receiver. The antenna arrangement is designed as an antenna system having several individual antennas and several antenna components, and contains a controllable logic switching device. The individual antennas and the several antenna components are positioned on the vehicle so that for discrete switching positions of the controllable logic switch, reception signals that are different in terms of diversity are available at the antenna connection point. A reception level testing device is provided for the comparative determination of the reception level contained in the data flow in the HF-channel with an HF channel bandwidth B.

Abstract: Methods and systems for measuring coordinates of a target, particularly under strong multipath conditions, are described. A satellite navigation system antenna and a tilt sensor are mounted on a range pole, with the sensor at the pole's bottom tip. Signals from the antenna and tilt sensor are provided to a receiver, which computes the antenna's coordinates from the antenna signals, and the pole tips position from the computed coordinates and the tilt data. The operator places the pole tip on the target and swings the pole by hand over an angle sector of 15 degrees while keeping the tip on the target. Height of the target can be computed with a single measurement set, and X-Y coordinates with just three measurement sets. The use of additional measurements reduces errors in the target's coordinates since multipath errors are uncorrelated during movement of the antenna. Vertical alignment of the pole is unnecessary.

Abstract: Method and apparatuses for receiving and tracking satellite signals in a highly sensitive and accurate receiver. In one aspect of the invention an exemplary method includes generating a set of at least three indicators based on processing a portion of a satellite positioning system signal received by a receiver and computing a measurement of a parameter from an interpolation of the set of indicators. Each of the indicators corresponds to a different predetermined hypothesized value of the parameter and is indicative of a probability, or likelihood, that the parameter of the signal is equal to that corresponding value.

Abstract: A system and method for automatically generating a return beam in the direction of a received beam. The inventive system (10) includes a phased array antenna (12) for receiving a radio frequency signal having a first wavefront from a first direction. In response to this signal, the invention (10) provides a second signal having a second wavefront. The second signal is a phase conjugate of the first signal and is transmitted in a reverse direction relative to the direction of the first signal. In the illustrative embodiment, the invention includes a plurality of phase conjugators each of which are disposed in a transmit/receive module and coupled to an associated radiating element. Each of the phase conjugators includes a mixer (60) having the input signal as a first input thereto. The input signal has a first frequency and a first phase.

Abstract: A vehicle information system which includes an in-vehicle system 105 and a centralized server system 120. The in-vehicle system communicates with the server system using a wireless communication link 110, such as over a cellular telephone system. A position system, such as a set of GPS satellites 140, provides positioning signals that are used by the in-vehicle systems, and optionally by the centralized server system to increase the accuracy of position estimates. In one version of the system, an operator specifies a destination to an in-vehicle system which validates the destination. The in-vehicle system transmits specification of the destination to a server system 125 at the centralized server. The server system computes a route to the destination and transmits the computed route to the in-vehicle system. The in-vehicle system guides the operator along the route.

Abstract: A method for processing positioning signals in a ranging receiver in a stand-alone mode is provided. The method includes collecting pseudorange samples from positioning signals received at the ranging receiver from a plurality of satellites. The pseudorange samples comprise message data modulation. Each satellite has an associated Gold code. A previously determined carrier frequency offset (CFO) is selected from a plurality of directly extracted CFOs. The pseudorange samples are compensated for the selected CFO. The message data modulation is removed from the pseudorange samples. The pseudorange samples are stacked for each satellite. The Gold code associated with each satellite is correlated to generate a pseudorange time sequence for the satellite. A determination is made regarding whether an adequate correlation peak exists in each pseudorange time sequence.

Abstract: A method for handing-off phased array antenna signals is provided. A phased array multiple antenna system receives and demodulates signals using one receiver. The phased array antennas are controlled electronically by an antenna controller. An antenna switch matrix in the antenna controller selects between signals from a handing-off antenna and a handed-to antenna. A phase comparator compares the two signals and produces a phase error signal proportional to the difference between the phase angles of the two signals. A negligible phase error difference is predetermined wherein antenna handoff can occur without causing loss of phase lock on the handed-to antenna signal. When the antenna controller signals a hand-off and the phase error equals the negligible phase error difference, a fast switch performs the hand-off. Power consumption is also controlled by requiring only one antenna to be powered “on” at a time.

Abstract: By using the GPS satellite transmitted signals that are tracked on a satellite and those that should be tracked but are not due to the attitude of the satellite and rotating the satellite, two estimations of satellite attitude are made that are used to change the satellite attitude so that all the GPS signals are tracked.

Abstract: A system for mitigating the effects of interference in an unlicensed RF band for point to point data transmissions comprises a multibeam antenna locating interference with transmission to and from data transmission subscribers. A scanner determines the frequency, bandwidth and any periodicity of the interference. Separate scanners can be used for each antenna beam. Nulls are generated in the data transmission antenna pattern in the direction of the interference during periods of interference. Communications with subscribers in a direction of the interference is carried out using a different channel or is scheduled around the interference occurrences. Alternatively, such subscribers are directed to establish data transmissions with an alternate hub antenna.

Abstract: A vehicle information system which includes an in-vehicle system 105 and a centralized server system 120. The in-vehicle system communicates with the server system using a wireless communication link 110, such as over a cellular telephone system. A position system, such as a set of GPS satellites 140, provides positioning signals that are used by the in-vehicle systems, and optionally by the centralized server system to increase the accuracy of position estimates. In one version of the system, an operator specifies a destination to an in-vehicle system which validates the destination. The in-vehicle system transmits specification of the destination to a server system 125 at the centralized server. The server system computes a route to the destination and transmits the computed route to the in-vehicle system. The in-vehicle system guides the operator along the route.

Abstract: Wireless network devices can obtain their geographical location by triangulating with access points that have precise time information. In response to a location prompt, a wireless device can send a transmission to multiple access points that are within its range. The different times at which the transmission is received at different access points can be collected and forwarded to a server, which can compute the location of the wireless device using triangulation techniques. The access points can calibrate their own time bases from time services received from global position satellites.

Abstract: A system using GPS data for locating a person requesting a support. The system includes a mobile terminal carried by a person to acquire the GPS data from GPS satellites and transmits the same upon a request by the person to a message center where the GPS data is processed to calculate the person(s position. The mobile terminal simply acquires the GPS data which is invalid for calculation of the position if the request is made where the GPS satellite is not available. For successfully locating the person's position, the mobile terminal acquires the GPS data regularly at different times in accordance with a time schedule and stores the time-series sets of the GPS data which are transmitted together with a current GPS data acquired in response to the support request, thereby giving the latest available position of the person if the current GPS data is found invalid.

Abstract: In order to reduce power consumption of battery-powered devices to which location data is to be dissemination by short range communication, the devices are arranged to wake-up to listen for location data at known times as judged against a reference time standard. This time standard is also available to the transmitters of location data which accordingly transmit their location data at the known times.

Abstract: A vehicle tracking system, wherein with respect to vehicles owned by members on which communication units containing GPS receivers are mounted, the vehicle tracking system specifies a previously-registered member and the vehicle owned by the previously-registered member based upon a request of the previously-registered member for providing positional information of a vehicle owned by the previously-registered member, and the vehicle tracking system executes a polling operation of positional information to the vehicle owned by the previously-registered member; retrieves an existence position of the vehicle on a map from a map database based upon positional information transmitted from the vehicle owned by the previously-registered member; displays the existence position of the vehicle by superimposing on the map; and provides the existence position superimposed on the map as vehicle positional information data to the previously-registered member.