Abstract: In a portable phone, a signal received by a GPS antenna passes through a SAW filter and is amplified by an LNA. An addition section adds a cancellation signal generated by a cancellation signal generation section to the amplified signal to cancel noise superimposed on the received signal.

Abstract: A device for detecting and tracking vehicles includes a position-determining device for determining a current vehicle position, a transmitting device for transmitting the current vehicle position to a receiver via a communication channel, and a device for detecting an activated interfering transmitter and for triggering an action depending on the detection of an activated interfering transmitter.

Abstract: Method and system for determining, via sensor network, position of GNSS receiver arranged in a motor vehicle intentionally is impaired in a targeted manner by interference source. Sensor network includes traffic route points having at least one sensor to detect a presence of interference source. Method includes detecting, as motor vehicle passes one of traffic route points, an interference signal emitted by interference source and/or a received signal of GNSS receiver impaired by interference source by the at least one sensor of the one traffic route point; processing the detected signals to establish whether interference source is present in passing motor vehicle; and when the presence of interference source established, generating information that signals at least a location of the one traffic route point and the interference source in the motor vehicle. A position of the motor vehicle is determined from the location of the traffic route point.

Abstract: A satellite navigation receiver having a digital front end. The satellite navigation receiver includes an analog section for receiving, amplifying, and filtering a satellite navigation signal. The digital front end is coupled to the analog section and is used to perform digital signal processing on the satellite navigation signal before it is passed on to the acquisition and tracking engines. By off-loading some of the functionality from the analog section to the digital front end, the analog section may be made smaller and cheaper and may consume less power. Moreover, additional functionalities can be added to the digital front end to improve performance. Since the digital front end is comprised of digital circuitry, it scales down in size, cost, and power with advances in semiconductor fabrication techniques.

Abstract: A method and apparatus for improving anti-jamming performance are provided. A threshold value level estimated in a GPS (global positioning system) receiver RF/IF stage, a threshold value weight, a median value of a median value of a 2-8 MHz bandwidth is estimated as a threshold value with respect to a frequency component exceeding the estimated threshold value level, and an adjustable K-median threshold scheme is provided in a multi-jamming environment.

Abstract: A system and method for determining whether a wireless device has transmitted one or more forged satellite measurements. An estimated location of the wireless device may be determined as a function of information from a cellular network. Acquisition assistance data may be determined for a first set of satellites as a function of the estimated location, the assistance data including an uncertainty window. If measured code phase information in the satellite measurements substantially correlates to the uncertainty window, then the wireless device may be transmitting forged satellite measurements.

Abstract: Method for locating sources interfering with a satellite-based radionavigation signal comprising the following steps: a step of calculating the intercorrelation matrix Rxx of the signals received by the elementary antennas of the said array, a step of determining a plurality of pointing vectors Ss whose components are the antenna gains, in a given direction of pointing {right arrow over (u)}s, of each elementary antenna of the said array, a step of calculating, for each assumption of direction of pointing {right arrow over (u)}s, the power of the signal received in this direction by the array of antennas, a step of searching for maxima among the set of powers Psf calculated and of locating interfering sources in the directions of pointing {right arrow over (u)}s corresponding to the said maxima, an ambiguity resolution step consisting in eliminating, from the search step, the maxima relating to an ambiguity resulting from the geometry of the array.

Abstract: A global navigation satellite system (GNSS) enabled mobile device may be operable to assert one of autoblank signals when RF interference is detected in received GNSS signals for one of consecutive first time windows. The asserted autoblank signals are monitored by the GNSS enabled mobile device over time intervals corresponding to consecutive second time windows and a rate at which the autoblank signals are asserted for each of the consecutive second time windows is determined by the GNSS enabled mobile device based on the monitoring. The GNSS enabled mobile device may be operable to determine whether to blank processing of the received GNSS signals based on the determined rate. The autoblank signals may be asserted by the GNSS enabled mobile device based on a number of the received GNSS signals whose absolute signal levels exceed a signal level threshold for the first time window.

Abstract: A method for eliminating or reducing interference in a receiver, for example, interference in a satellite positioning system receiver caused by a co-located TDMA transmitter, including detecting (210) the presence of a jamming signal, generating a synchronous blanking signal (220), and reducing the jamming signal by blanking (230) the receiver with a blanking signal. In one embodiment, the jamming signal is detected in the receiver, for example, at a correlator output of a satellite positioning system receiver.

Abstract: The wireless communication device includes a wireless communication transceiver to generate an oscillator control signal and an activation signal, a positioning-system receiver (e.g. a GPS receiver) to process received positioning signals, and a shared oscillator (e.g. a temperature compensated and voltage controlled crystal oscillator TCVCXO) responsive to the oscillator control signal and to generate a reference frequency signal for the wireless communication transceiver and the positioning-system receiver. The positioning-system receiver may control processing of the received positioning signals based upon the activation signal to reduce a noise contribution (e.g. phase noise) due to frequency control of the shared oscillator based upon the oscillator control signal. The activation signal may indicate that the oscillator control signal is being varied to provide frequency control or adjustment of the shared oscillator.

Abstract: Embodiments provided herein recite methods and systems for an accuracy estimator for a position fix. In one embodiment, a solution receiver for receiving a code solution and at least one additional solution from a different solution technique is utilized. In addition, a table of metric values comprising an associated accuracy estimate for at least one characteristic of each of the code solution and the at least one additional solution is also utilized. A comparator compares the code solution and the at least one additional solution with the table of metric values. In addition, a solution orderer orders the at least one additional solution above or below the code solution dependent on whether the at least one additional solution is within a pre-defined offset distance threshold. If the at least one additional solution is outside of the distance threshold, the code solution is chosen as the final solution.

Abstract: An exemplary navigation system uses a master navigation component at a first location in a vehicle and a slave navigation component at a second location that is a variable displacement to the first location due to physical deformation of the vehicle. Static and dynamic location components provide static and dynamic information of the displacement between the first and second locations. An error estimator estimates errors in the navigational measurement data generated by the slave navigation component based on the navigational measurement data generated by the master navigation component and the displacement information provided by the static and dynamic location components. The master navigation component corrects the navigation measurement data of the slave navigation component based on the determined error and translates the corrected navigation measurement data of the slave navigation component into navigational measurement data in its coordinate system.

Abstract: A system and method for improving acquisition sensitivity and tracking performance of a GPS receiver using multiple antennas is provided. In an embodiment, the acquisition sensitivity can be improved by determining the correlation weight of each received path signal path associated with one antenna form a plurality of antennas and then combining the path signals based on their respective correlation weight. In another embodiment, carrier offset correction information of each path signal is individually determined and then summed together to be used for tracking the code phase in a code phase tracking loop. The code phase tracking loop generates an early code and a late code that are used to determine the code phase error. The system includes notch and bandpass filters to mitigate narrowband and broadband noises of a received GPS signal, wherein the digital adaptive filters are switched on periodically or by external events.

Abstract: A temporal nuller for removing or minimizing narrow band interference/jamming power from a global positioning system (GPS) receiver's input includes a first signal path having a first input and a first output, at least one time delay device and an adjustable phase shift device located within the first signal path, and a second signal path having a second input and a second output. The first signal input is connected to the second signal input, and the first signal output is connected to the second signal output. Further, the at least one time delay device is operative to introduce a time delay between a signal at an output of the at least one time delay device relative to a signal at an input of the at least one time delay device.

Abstract: A method to detect at a GNSS receiver whether the received GNSS signals and navigation messages are the product of an attack. If there is evidence, as provided by the method described here, that the received signals and messages originate from adversarial devices, then receiver equipped with an instantiation of the method notifies the user or the computing platform that integrates the GNSS receiver that the calculated via the GNSS functionality position and time correction are not trustworthy. In other words, our method enables any GNSS receiver, for example, GPS, GLONASS, or Galileo, or any other GNSS system, to detect if the received navigation messages are the legitimate ones (from the satellites) or not (e.g., from attacker devices that generate fake messages that overwrite the legitimate messages). Based on this detection, neither the user and nor any application running in the computing platform is misled to utilize erroneous position information.

Abstract: A system and method for operating a wireless transmitter and a global navigation satellite (“GNSS”) receiver coexistent in a mobile wireless device. A mobile wireless device includes a GNSS receiver and a wireless networking system. The wireless networking system includes a wireless transmitter. The wireless transmitter provides a first interference level signal to the GNSS receiver. The first interference level signal indicates a level of interference that the GNSS receiver can expect due to operation of the transmitter.

Abstract: To provide a GPS compound device having a configuration including a GPS receiver, that accurately determines abnormality in an output from the GPS receiver based on a difference between a GPS pseudorange measurement and a Doppler frequency measurement, when detecting the abnormality in the outputs from the GPS receiver, while avoiding continuation of the abnormality at the time of the abnormality determination resulting from estimation errors of the GPS pseudorange measurement and the Doppler frequency measurement. When the abnormality of the outputs from the GPS receiver are detected, an abnormal period is counted. When the count value is below a predetermined threshold, the outputs from the GPS receiver are treated as abnormal, and after it exceeded the threshold, the outputs from the GPS receiver are treated as normal. Thus, the abnormality of the outputs from the GPS receiver can be determined accurately.

Abstract: A method of providing automatic frequency control pull-in for efficient receipt of GLONASS bits is described. This method can include first determining whether a channel noise (CNo) is greater than or equal to a predetermined value. When the CNo is greater than or equal to the predetermined value, the pull-in can be performed using a first series of predetection integration periods (PDIs) with activated decision-directed flips (DDFs) until a 20 ms boundary of a GLONASS data bit is found. When the CNo is less than the predetermined value, the pull-in can be performed using a second series of PDIs with always deactivated DDFs. A similar method of providing automatic frequency control pull-in for efficient receipt of GPS bits is also described.

Abstract: Embodiments of a global navigation satellite system (GNSS) receiver and method for navigation are generally described herein. In some embodiments, the GNSS receiver includes signal processing circuitry to systematically identify clear channels from channels with persistent interference by performing two or more signal measurements within each of a plurality of channel bands. The channel bands include at least channel bands of at least two or more different global positioning satellite systems such as GPS satellites, GALILEO system satellites or GLONASS system satellites. In some embodiments, the GNSS receiver provides for self-adapting jamming avoidance in satellite navigation systems.

Abstract: A method for operating a wireless transmitter and a global navigation satellite (“GNSS”) receiver coexistent in a mobile wireless device. A mobile wireless device includes a GNSS receiver and a wireless networking system. The wireless networking system includes a wireless transmitter. The wireless transmitter provides a first interference level signal to the GNSS receiver. The first interference level signal indicates a level of interference that the GNSS receiver can expect due to operation of the transmitter. A priority signal is asserted if the processing of navigation signals in the GNSS receiver takes precedence over wireless transmitter transmissions.

Abstract: A method, device and system for determining a receiver location using weak signal satellite transmissions. The invention involves a sequence of exchanges between an aiding source and a receiver that serve to provide aiding information to the receiver so that the receiver's location may be determined in the presence of weak satellite transmissions. With the aiding information, the novel receiver detects, acquires and tracks weak satellite signals and computes position solutions from calculated pseudo ranges despite the inability to extract time synchronization date f, 'n the weak satellite signals. The invention includes as features, methods and apparatus for the calibration of a local oscillator, the cancellation of cross correlations, a Doppler location scheme, an ensemble averaging scheme, the calculation of almanac aiding from a table of orbit coefficients, absolute time determination, and a modified search engine.

Abstract: Embodiments of a global navigation satellite system (GNSS) receiver and method for navigation are generally described herein. In some embodiments, the GNSS receiver includes signal processing circuitry to systematically identify clear channels from channels with persistent interference by performing two or more signal measurements within each of a plurality of channel bands. The channel bands include at least channel bands of at least two or more different global positioning satellite systems such as GPS satellites, GALILEO system satellites or GLONASS system satellites. In some embodiments, the GNSS receiver provides for self-adapting jamming avoidance in satellite navigation systems.

Abstract: A system and method for determining the roll rate and roll angle of a spinning platform in a jamming environment, by suppressing the interference signals from the received GPS signals and using the measured phase and amplitude differences between the GPS satellite signals received on two or more antennas. The measured signal differences and the navigation solution from a GPS receiver are processed in a roll filter to obtain the desired information. Data from non-GPS measurement sources is optionally provided to update the navigation solution. Although of wide applicability, the invention is uniquely suited to the measurement of roll rates and roll angles of fast spinning platforms with small baselines in the presence of jamming, and where the antennas are separated from each other by distances that are a fraction of the GPS signal wavelength.

Abstract: Flight management systems can behave erratically when the distance measurements on which they are based are subject to value jumps because they liken these value jumps to movements of the aircraft performed at speeds exceeding the performance levels of the aircraft for which they were designed. To avoid this, the proposed flight management system uses a filter to spread the distance value jumps in time, over periods of the order of those needed for the aircraft to come through the distance differences that they represent. This filter replaces a value jump with a ramp making up the difference and corresponding to a movement that remains within the performance scope of the aircraft.

Abstract: A global navigation satellite system (GNSS) enabled mobile device may be operable to assert one of autoblank signals when RF interference is detected in received GNSS signals for one of consecutive first time windows. The asserted autoblank signals are monitored by the GNSS enabled mobile device over time intervals corresponding to consecutive second time windows and a rate at which the autoblank signals are asserted for each of the consecutive second time windows is determined by the GNSS enabled mobile device based on the monitoring. The GNSS enabled mobile device may be operable to determine whether to blank processing of the received GNSS signals based on the determined rate. The autoblank signals may be asserted by the GNSS enabled mobile device based on a number of the received GNSS signals whose absolute signal levels exceed a signal level threshold for the first time window.

Abstract: A system for receiving a radionavigation signal, notably in a jammed medium, emitted by a satellite of a satellite positioning system, includes: at least one first multi-correlator and at least one second multi-correlator disposed in parallel and operating respectively at a frequency; filtering means, disposed upstream of said multi-correlators; a delay line, disposed on the branch, between the filtering means and the second multi-correlator; means for sub-sampling at the frequency adapted for sub-sampling the signal transmitted directly and by branching with delay by the filtering means; and demodulation means eliminating the Doppler effect, disposed between the sub-sampling means and the first and second multi-correlators.

Abstract: A system and method for determining whether a wireless device has transmitted one or more forged satellite measurements. An estimated location of the wireless device may be determined as a function of information from a cellular network. Acquisition assistance data may be determined for a first set of satellites as a function of the estimated location, the assistance data including an uncertainty window. If measured code phase information in the satellite measurements substantially correlates to the uncertainty window, then the wireless device may be transmitting forged satellite measurements.

Abstract: An advanced multiple-beam GPS receiving system is achieved that is capable of simultaneously tracking multiple GPS satellites independently, detecting multiple interference signals individually, and suppressing directional gain in the antenna pattern of each beam in the interference directions. The GPS receiving system can be used for both planar and non-planar receiving arrays, including arrays that are conformally applied to the surface of a platform such as an aircraft. The GPS receiver combines spatial filtering and acquisition code correlation for enhanced rejection of interfering sources. Enhanced gain in the direction of GPS satellites and the ability to shape the beam patterns to suppress gain in the direction of interfering sources make the GPS receiving system largely insensitive to interfering and jamming signals that plague conventional GPS receivers.

Abstract: A navigation system for a vehicle having a receiver operable to receive a plurality of signals from a plurality of transmitters includes a processor and a memory device. The memory device has stored thereon machine-readable instructions that, when executed by the processor, enable the processor to determine a set of error estimates corresponding to pseudo-range measurements derived from the plurality of signals, determine an error covariance matrix for a main navigation solution using ionospheric-delay data, and, using a solution separation technique, determine at least one protection level value based on the error covariance matrix.

Abstract: A global navigation satellite system (GNSS) enabled mobile device may be operable to monitor and determine counts at which autoblank signals are asserted over time intervals corresponding to consecutive time windows during the RF interference mitigation process using autoblanking. The GNSS enabled mobile device may be operable to disable the generation of a blank signal when the count may be greater than a particular count threshold at the end of the time window. The GNSS enabled mobile device may be operable to enable the generation of a blank signal when the count may be less than or equal to a particular count threshold at the end of the time window. The blank signals may be used to blank the processing of the received GNSS signals.

Abstract: A method for self-calibration of frequency offsets in a measurement equipment of an interference monitoring system is provided. The method involves sampling I/Q data using the interference monitoring system measurement equipment and acquiring satellite navigation signals from the I/Q data. A carrier frequency of the satellite navigation signal is estimated and an expected carrier frequency of the satellite navigation signal is calculated. The expected carrier frequency of the satellite navigation signal is compared with the estimated carrier frequency of the satellite navigation signal and a frequency offset value is calculated as the difference between the expected and estimated carrier frequencies of the satellite navigation signal. The frequency offset value is stored in a memory and used to compensate the frequency offset of at least one subsequent measurement.

Abstract: In a portable phone, a signal received by a GPS antenna passes through a SAW filter and is amplified by an LNA. An addition section adds a cancellation signal generated by a cancellation signal generation section to the amplified signal to cancel noise superimposed on the received signal.

Abstract: Authentication of a signal, signalA, that is provided as having been received from a source at a first global location by comparing it to a signal that is received from the source at a second global location, signalB, where signalB contains an unknown signal that is unique to the source, and determining, that signalA contains the same unknown signal that is contained in signalB.

Abstract: A system and method for detecting one or more forged satellite measurements transmitted from a wireless device. Information may be transmitted to a wireless device, the information including a request that the wireless device provide a portion of a navigation data message from one or more satellites to a location determining system. The one or more satellite measurements and the portion of the navigation data message may be received from the wireless device. The navigation data message may be determined as a function of information from a reference network. The determined navigation data message may then be compared with the received navigation data message portion to thereby determine whether any of the one or more satellite measurements transmitted by the device have been forged.

Abstract: A system and method for determining whether a wireless device has transmitted one or more forged satellite measurements. An estimated location of a wireless device may be determined as a function of signals from a cellular network. For each one of a first set of satellites from which the wireless device receives a signal, expected frequency information may be determined as a function of the estimated location, actual frequency information may be measured, and the expected frequency information compared with the measured frequency information. One or more satellite measurements received from the wireless device may then be identified as forged if a difference between the expected and measured frequency information is greater than a predetermined threshold.

Abstract: A method of countering GNSS signal spoofing includes monitoring a plurality of GNSS signals received from a plurality of GNSS signal sources and comparing broadcast data to identify outlying data, which is excluded from generation of a navigation solution defined by the plurality of GNSS signals. The outlying data can be a vestigial signal from a code or carrier Doppler shift frequency. The method includes triggering a spoofing indicator upon identification of the outlying data or other phenomenon. The phenomenon can include a shift in a phase of a measured GNSS navigation data bit sequence or a profile phenomenon of a correlation function resulting from correlation of the incoming GNSS signals with a local signal replica. The profile phenomenon can be the presence of multiple sustained correlation peaks. A nullifying signal can be generated and superimposed over a compromised signal.

Abstract: A system and method for compensating for faulty satellite navigation measurements. A plurality of measurements in a system is received for a measurement epoch. A Kalman filter is used to calculate a state of the system for the measurement epoch based on the plurality of measurements, wherein the state of the system for the measurement epoch is calculated using a first closed-form update equation. A faulty measurement is detected in the plurality of measurements for the measurement epoch and a revised state of the system for the measurement epoch that compensates for the faulty measurement is calculated, using the calculated state of the system for the measurement epoch as an input to the revised state calculation, and using a revised closed-form update equation comprising the first closed-form update equation modified with respect to the faulty measurement.

Abstract: A global navigation satellite system (GNSS) enabled mobile device may be operable to monitor and determine counts at which autoblank signals are asserted over time intervals corresponding to consecutive time windows during the RF interference mitigation process using autoblanking. The GNSS enabled mobile device may be operable to disable the generation of a blank signal when the count may be greater than a particular count threshold at the end of the time window. The GNSS enabled mobile device may be operable to enable the generation of a blank signal when the count may be less than or equal to a particular count threshold at the end of the time window. The blank signals may be used to blank the processing of the received GNSS signals.

Abstract: Enhancing position accuracy in global positioning system receivers. A pseudorange is measured, in a receiver, from each signal of a plurality of signals. Each signal is received from a different one of a plurality of satellites. A check is performed for an inconsistency among measured pseudoranges. Each measured pseudorange corresponds to the different one of the plurality of satellites. Further a power saving mode of the receiver is inactivated if the inconsistency is determined among the measured pseudoranges. Additionally, a position of the receiver is determined when the power saving mode is inactivated.

Abstract: A system and method for determining the roll rate and roll angle of a spinning platform in a jamming environment, by suppressing the interference signals from the received GPS signals and using the measured phase and amplitude differences between the GPS satellite signals received on two or more antennas. The measured signal differences and the navigation solution from a GPS receiver are processed in a roll filter to obtain the desired information. Data from non-GPS measurement sources is optionally provided to update the navigation solution. Although of wide applicability, the invention is uniquely suited to the measurement of roll rates and roll angles of fast spinning platforms with small baselines in the presence of jamming, and where the antennas are separated from each other by distances that are a fraction of the GPS signal wavelength.

Abstract: Systems and methods for detecting global positioning system (GPS) measurement errors are provided. In this regard, a representative system, among others, includes a navigation device that is configured to receive GPS signals from signal sources, the navigation device being configured to calculate pseudoranges (PRs) and delta ranges (DRs) based on the received GPS signals, the navigation device including a consistency check algorithm that is configured to: determine mismatches between the respective calculated PRs and DRs, and indicate that an error exists in the respective calculated PRs and DRs based on their mismatch and mismatch accumulations. This algorithm can be independent of navigation state and is capable of detecting slow-changing errors.

Abstract: A temporal nuller for removing or minimizing narrow band interference/jamming power from a global positioning system (GPS) receiver's input includes a first signal path having a first input and a first output, at least one time delay device and an adjustable phase shift device located within the first signal path, and a second signal path having a second input and a second output. The first signal input is connected to the second signal input, and the first signal output is connected to the second signal output. Further, the at least one time delay device is operative to introduce a time delay between a signal at an output of the at least one time delay device relative to a signal at an input of the at least one time delay device.

Abstract: A method and system for determining whether to allow a base station to carry out at least one particular base station function and for configuring the system, based on the determination, to allow the base station to carry out the at least one particular base station function or to prevent the base station from carrying out the at least one particular base station function. The determination may be carried out at the base station or at a base station controller (BSC). The determination may be based, at least in part, on whether data provided to the BSC from the base station comprises spoofed GPS data. Configuring the system may include setting at the base station or at the BSC at least one parameter to either allow the base station to carry out the base station function(s) or to prevent the base station from carrying out the base station function(s).

Abstract: A method of measuring the power of a signal from a transmitter (10) causing interference with a receiver (16) involves geolocating the transmitter (10) via satellites (24) and (28) or aircraft A1and A2. The receiver (16) is part of a satellite-implemented Global Navigation Satellite System. Geolocation involves finding a correlation peak between replicas of the transmitter's signal to determine their differential time and frequency offsets, from which a transmitter's location is calculated. The transmitter's signal power P1 is a solution to a quadratic equation with coefficients involving the transmitter's distances D1 and D2 from the satellites (24) and (28), its transmit wavelength ?, total noise temperature TN of each satellite's receiver system and antenna, correlation peak signal to noise ratio SNRc satellites' receive antenna gain Gs sample bandwidth B at outputs of the satellite receivers' ADCs and correlation integration time T.

Abstract: This invention relates to the troposphere delay produced when the electromagnetic waves from a satellite or astronomical pass through the troposphere, in particular, it is related with the calculation method of a estimated value of the amount of zenith troposphere delay to real time, and troposphere delay of the satellite positioning signal in the case of positioning using the estimated value of this calculated amount of zenith troposphere delay is related with a correcting method.