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: An improved GPS signal receiver (and corresponding method of operation) includes a plurality of antenna elements each receiving a plurality of GPS signals (e.g., GPS LI signals or GPS L2 signals). A plurality of mixers (which correspond to the array of antenna elements) and a combining node convert the GPS signals received at the antenna elements in a frequency-division-multiplexed (FDM) manner over FDM frequency bands logically assigned to the antenna elements to produce a composite signal representing such GPS signals. An analog-to-digital converter converts an analog signal derived from the composite signal (which may be an intermediate frequency signal or a baseband signal) into a digital word stream. Demultiplexing logic extracts GPS signal components in the digital word stream. The GPS signal components correspond to the FDM frequency bands logically assigned to the antenna elements.

Abstract: The present invention is useful in connection with calibration of a wireless location system based on RF signals within a facility. Identification devices are provided at fixed locations which are selected within the facility. The RF environment is sampled at selected locations and data representing the sampled RF environment and the corresponding selected location is provided to a computer which maintains a database corrolating the RF environment data and the selected locations to be used with calibrating a location system.

Abstract: The apparatus/method according to the present invention accomplishes a reduction in the total number of direct digital synthesizers (DDSs) needed for use in electronically scanned antenna array to generate multiple simultaneous radio frequency (RF) beams. The apparatus includes, inter alia, a multi-beam forming synthesizer, a plurality of DDSs, a corresponding plurality of amplifiers all operatively connected to a plurality of radiating elements of the antenna array. This arrangement uses a single DDS per radiating element. Each DDS uses a composite amplitude, phase and frequency information computed by the multi-beam forming synthesizer to create the proper waveform for driving the antenna array, and accordingly, generating the desired multiple simultaneous RF beams, i.e. 1-M (e.g. 1 through M) RF beams each of which can have a different frequency and separate modulation.

Abstract: A method of providing an estimate of GPS time from non-GPS timing information present in communications signals transmitted from a base station (BS1) to a first mobile communications device (MS1) is provided comprising the steps of (i) in a second mobile communications device (MS2), receiving corresponding non-GPS timing signals present in communications signals transmitted by the base station; (ii) in a GPS receiver (23, 24) of the second mobile communications device (MS2), obtaining at least one pseudorange to a GPS satellite (GPS SV) and obtaining an first estimate of GPS time; (iii) deriving a relationship between the receipt of timing signals received in step (i) and the estimate of GPS time obtained in step (ii); and (iv) from the non-GPS timing information received by the first mobile communications device (MS1) and the relationship derived in step (iii), calculating a second estimate of GPS time.

Abstract: In a cellular mobile telecommunications system the position of a mobile station can be estimated in terms of its bearing and range from a cell site. A multi-element direction finding antenna at the cell site receives signals from the mobile station and a receiver circuit estimates the bearing using the relative phase of signals received at different antenna elements and estimates the range by measuring round trip delay of signals to and from the mobile station. Motion of the mobile station can introduce errors into the bearing estimate due to frequency offset and frequency spread when element sampling is non-simultaneous. Compensation for these errors is introduced by using signal samples successively received at the same antenna element to estimate Doppler frequency offset and spread. It is necessary to ensure accurate calibration of the direction finding antenna and the receiver circuit.

Abstract: A method for processing positioning signals in a ranging receiver in a geometric mode is provided. The method includes receiving timing information from a first set of satellites in a satellite constellation at the ranging receiver. The satellite constellation includes a plurality of satellites. A time of day is determined based on the received timing information. Approximate location data for the ranging receiver is determined. A frequency bias for the ranging receiver is determined. Ephemeris data is received from a second set of satellites in the satellite constellation. Superframe data for the satellite constellation is received from a third set of satellites in the satellite constellation at the ranging receiver. A pseudorange estimate is determined in the ranging receiver based on the time of day, the approximate location data, the frequency bias, the ephemeris data, and the superframe data.

Abstract: Systems and methods for notifying a user that a specified person is within a specified distance of a specified meeting location are disclosed. A method according to the invention includes receiving a location signal that represents a current location of a specified party, storing identity data that represents an identity of the specified party and location data that represents a specified location, and determining from the location signal and the location data whether the specified party has arrived at the specified location. Such a method can also include transmitting a notification message if the specified party has arrived at the specified location.

Abstract: An approach to antenna design optimizes gain, beam pattern, polarization response, and other qualities through self-replicating patterns based upon iterative transformations and candidate geometric shapes. In the preferred embodiment Hausdorff structures are used to realize &lgr;n-arbitrary different radiation patterns, including patterns optimized for multiple frequencies. The most preferred approach applies a sequence of different Hutchinson operators to different geometric subsets, thereby achieving patterns which are not only arbitrary in terms of wavelength/frequency, but also permit variable radiation patterns and variable polarization other desirable criteria. In addition to the use of variable scaling, geometric patterns, and the like, multiple structures may be placed within the same spatial footprint to permit reception over more bands.

Abstract: A method for acquiring azimuth information enables acquisition of azimuth information by receiving signals transmitted by GPS satellites using only a single antenna.

Abstract: A configurable directional antenna includes a center antenna element, a plurality of second antenna elements, and a switch matrix. Each second antenna element, together with the center antenna element, defines an antenna sector. A first portion of the second antenna elements is disposed at an inner radius around the center antenna element. A second portion of the second antenna elements is disposed at an outer radius around the first portion antenna elements. Each antenna sector comprises one of the radially inner antenna elements, one of the radially outer antenna elements, and a conductor extending between the one radially inner and the one radially outer antenna element. The switch matrix comprises first electronic switches for selectively grounding selected ones of the second antenna elements, and second electronic switches each for selectively connecting together the second antenna elements of one of the antenna sectors with the associated conductor.

Abstract: A method and receiver are disclosed for mitigating or substantially canceling signal interference between signals detected at the receiver. Once a presumed interfering signal(s) is acquired, parameters are determined that allow the interferer(s) to be modeled. An orthogonal projection (for projecting onto a subspace orthogonal to that spanned by the interferer(s)) is applied to the composite of all signals (y) for thereby projecting y onto this subspace, wherein the subspace is non-orthogonal to a representation of desired (but interfered) signal of the composite signals. With the receiver properly equipped to perform this projection operation, interfering signals, multipath, spoofing and/or meaconing can be effectively diminished.

Abstract: The invention relates to a method for positioning a receiver receiving code modulated signals transmitted by satellites and formed by an individual code for each satellite. In order to provide a reliable reference position for the receiver, it is proposed that in a first step, a reference position for said receiver is calculated based on frequency measurements of said code modulated signals. This reference position can then be employed in a second step for determining the accurate position of the receiver. The invention equally relates to such a receiver, to positioning means, to a computing server and to a positioning system comprising means for realizing the proposed method.

Abstract: A method and computer program product are disclosed for locating signal jammers in a digital beamforming receiver having an antenna with a plurality of associated antenna orientations. An associated antenna gain value is calculated for a first of a sequence of the plurality of antenna orientations at each of a series of sample points. The antenna gain values from the first antenna orientation are evaluated for null spaces to obtain a set of candidate null locations. Associated antenna gain values are calculated and evaluated for subsequent antenna orientations only at the set of candidate null locations. Candidate null locations are eliminated from the set after any evaluation in which they are not found to be null spaces.

Abstract: A method and apparatus for determining and correcting for phased array mispointing errors, particularly those due to structural deformation, is disclosed. The method comprises the steps of receiving a signal from each of a plurality of signal sources at at least one receiving sensor disposed away from the phased array in a direction at least partially toward a receiver of a transmitted signal from the phased array, and determining the phased array pointing from the received signals. The apparatus comprises a receiving sensor for receiving a signal from each of a plurality of signal sources, the receiving sensor disposed away from the phased array in a direction at least partially toward a receiver of a transmitted signal from the phased array, and an array pointing computer for determining the direction of the phased array from the received signals.

Abstract: The invention relates to a diversity reception system for motor vehicles for digitally modulated terrestrial and/or satellite radio signals in a frequency range above 1 GHz. The system includes an antenna arrangement which supplies the reception signal to a radio receiver. The antenna arrangement is 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 different reception signals are available at the antenna connection point via discrete switching positions of a controllable logic switch. A reception level testing device comparatively determines the reception level contained in the data flow in the HF-channel with an HF channel bandwidth B.

Abstract: The invention relates to a method for determining the correlation between a signal transmitted by a beacon and tracked by a receiver and a reconstructed signal expected to be received at the receiver, wherein the received signal and the reconstructed signal are shifted against each other. In order to provide a possibility of compensating residual sinusoidal modulations in the tracked signal, it is proposed that at each shifting position, the samples of the received and the reconstructed signal are multiplied and integrated separately in a plurality of sections. The results are multiplied with a shifted and complex conjugated version of itself. The products resulting in this second multiplication are integrated to receive a single final value for each shifting position. Finally, the maximum final value resulting for the different shifting positions is determined, the shifting position with the maximum value being considered as the shifting position with the maximum correlation.

Abstract: An active array radar system is controlled by photonic signals. The array of N antenna elements is divided into M subarrays, each having N/M antenna elements. Tunable lasers provide M optical wavelengths within non-overlapping bands. For transmission, a microwave transmit pulse is amplitude modulated onto the M optical signals. Time delays are introduced for an offset between elements in a subarray and for an offset between subarrays. By using wavelength division multiplexing each antenna element on the array has a true time delay.

Abstract: An array antenna system with an electrically large array antenna comprises first and second antenna subarrays and, a combination transmission line network, which has an input for receiving an antenna line signal and outputs connected with the first and second antenna subarrays. The combination line network contains a phase shifting device for generating a phase displacement between output signals of the first output and of the second output before their feeding to the antenna subarrays; and devices are provided to compensate the phase displacement in the beam path of the antenna radiation emitted by the antenna subarrays.

Abstract: There is provided a mobile radio with Global Positioning System (GPS) capability. The mobile radio with GPS capability includes a GPS receiver and a mobile radio transceiver. The GPS receiver receives position information from GPS satellites for presentation to a user of the mobile radio. The mobile radio transceiver transmits and receives radio frequency (RF) signals. The RF signals include at least one of speech and the position information.