Abstract: A method and chipset for tracking a global navigation satellite system (GNSS) within the constraints of an indoor facility. The method includes receiving assistance information on the GNSS on a mobile communication system; and sorting orbiting satellites within the GNSS by elevation angles. Additionally, lower elevation satellites are correlated within the GNSS prior to correlating higher elevation satellites.

Abstract: An anti-jamming subsystem for jamming signals originating along the horizon includes a two-dimensional horizontal array of antennas that effectively has a horizontal circular reception pattern for receiving signals originating along the horizon and a antenna that has a half hemispherical reception pattern and an upward looking view of the sky. The subsystem utilizes associated phase information to actively combine the signals received by the respective antennas in the array, to produce one or more anti-jamming signals with narrow beams in the directions of the jammers. The subsystem combines the anti-jamming signals with the signals received by the reference antenna, to produce signals for further processing in which the interference from the jamming signals originating along the horizon is minimized without adversely affecting the signals received by the reference antenna from at least higher elevation satellites.

Abstract: An apparatus and a method for inter-vehicle communication includes a communicator communicating with another vehicle and a position determiner verifying position information of a vehicle, A controller is configured to synchronize a time point of transmitting/receiving a message to/from the other vehicle through a signal from the position determiner, performing a phase control for transmitting message, and transmitting the message to the other vehicle at a determined time point of transmitting the message according to the phase control result.

Abstract: An approach is provided for correcting a reference clock of a GPS receiver. The approach involves determining one or more frequency offset values. The approach also involves determining one or more codes associated with one or more satellites. The approach further involves determining a second code associated with the one or more satellites. The approach additionally involves determining one or more delay values between the second code and the one or more first codes. The approach also involves determining one or more proportional values based on the one or more delay values and a determined correlation. The approach further involves determining one or more correlation peak values and determining one or more estimated frequency offset error values based on the one or more correlation peak values. The approach additionally involves causing a calibrated reference clock frequency value to change to a recalibrated reference clock frequency value based on the estimated frequency offset error values.

Abstract: A ground station antenna including a torus shaped reflector having multiple feed points along a focal arc in front of the reflector. The ground station antenna includes transceiver feeds having their electrical phase centers located on the focal arc and supported by a rotating feed platform. The transceiver feeds are configured to simultaneously track rising and falling satellites when the platform rotates. The ground station antenna further includes a wireless power receiver coupled to the transceiver feeds to power the transceiver feeds. The ground station antenna further includes a wireless signal interface coupled to the transceiver feeds to communicate signals with a base unit to perform subsequent processing.

Abstract: Control and feature systems for processing signals from a satellite positioning system include an expert system receiver manager; a joint detection, carrier centring and bit sync acquisition subsystem; peak detection; a multi-dimensional measurement interpolation subsystem; a system for mode switching between a navigational signal; and power control module for receiver.

Abstract: A satellite signal searching method includes: determining, based on transmitted signal information in which whether satellite signals are transmitted from positioning satellites is managed for each signal type, and characteristics of the signal types, the order of searching the satellite signals.

Abstract: Apparatus, the apparatus having at least one processor and at least one memory having computer-readable code stored thereon which when executed controls the at least one processor to perform a method comprising: obtaining in-phase and quadrature samples of a received radio signal at least first and second discrete instances in time; processing the samples to provide information relating to the amplitude and/or phase of the received radio signal at the first and second instances in time; using the amplitude and/or phase information of the received radio signal at the first and second instances in time to determine whether interference is present on the received radio signal; forwarding the complex signal parameters for processing if interference is determined not to be present; and discarding the complex signal parameters without forwarding them for processing if interference is determined to be present.

Abstract: Asynchronous Global Positioning System (GPS) baseband processor architectures with a focus on minimizing power consumption. All subsystems run at their natural frequency without clocking and all signal processing is done on-the-fly.

Abstract: A navigation receiver operably coupled to an antenna can determine location by receiving and processing radiofrequency navigation signals from global navigation satellites. The navigation receiver includes a quartz crystal oscillator that serves as a reference frequency source for a local oscillator signal that is mixed with the radiofrequency navigation signals to generate intermediate signals at intermediate frequencies lower than the radiofrequencies. In particular applications, the quartz crystal oscillator and the antenna are subjected to vibration and shock. A shift in the frequency or phase of the intermediate signals can result, and performance of phase-lock loops can degrade. Performance is improved with a phase-lock loop that processes a combination of individual channel control signals and common control signals.

Abstract: A method of acquiring a satellite signal in a GNSS receiver includes multiplying a received signal with a hypothesized doppler frequency signal to generate a frequency shifted signal. A PN code sequence signal is multiplied with the frequency shifted signal to generate a PN wiped signal. A windowing function signal is multiplied with the PN wiped signal to generate a windowed signal. The windowed signal is integrated coherently for a first predefined time to generate a coherent accumulated data.

Abstract: A global navigation satellite system configured to operate in a noisy environment receives the same satellite signals in two separate channels. Each channel processes the signals independently according to different filtering constraints; one channel applies narrow filtering constraints while the other channel applies broader filtering constraints. Narrow filtering constraints allow the receiver to acquire a usable signal under certain conditions but not while moving rapidly. Broader filtering constraints allow the receiver to acquire a usable signal during rapid movement, but cannot overcome intense interference. A device implementing both constraint options is usable under a wider range of situations.

Abstract: Systems and methods for extracting synchronization information from ambient signals, such as broadcast television signals, and using the synchronization information as a reference for correcting the local time base so that a GNSS positioning receiver system maintains relative time base accuracy with respect to a GNSS time.

Abstract: A method of processing signals from a satellite positioning system, comprises receiving (50) recorded blocks of data samples of satellite broadcast, each block including one or more timestamps generated within a receiver at which the samples were recorded, and processing (52) the recorded blocks of data samples using a first set of processing parameters to identify satellite transmissions contained within the blocks. Based on the results of the processing (52), one of the blocks is selected (56,58). The selected block is processed (60) using a second set of processing parameters to derive at least position and satellite broadcast timing information. The timestamp of the selected block and the timing information obtained from the processing (60) of the selected block is used to assist in the processing (60) of the other blocks.

Abstract: A receiver for a multi-mode navigation system includes a base band unit and a calculation unit. The base band unit is configured for allocating resources to positioning satellites in each of one or more navigation system, and tracking the positioning satellites with the allocated resources to obtain satellite information of each of the positioning satellites. The satellite information includes one or more of pseudo-ranges, position coordinates, velocity information, and frequency information of the positioning satellites. The calculation unit is configured for receiving the satellite information from the base band unit, evaluating the positioning satellites in each navigation system, and determining a positioning parameter of the receiver. Determination of the positioning parameter includes calculating a position and a velocity of the receiver based on the satellite information according to a least square algorithm.

Abstract: A receiver associated with a positioning system is provided. The receiver comprises a tracking loop and a signal strength calculating module. The tracking loop is configured for tracking a positioning signal and generating an in-phase signal and a quadrature signal based on the positioning signal. The signal strength calculating module is configured for calculating a first evaluation value and a second evaluation value related to the positioning signal based on the in-phase signal and the quadrature signal, respectively, and determining a status of the tracking loop based on at least one of the first evaluation value and the second evaluation value.

Abstract: A method and a system for reducing time to first fix (TTFF) in a satellite navigation receiver generate a navigation data structure including three sub-frames. A first sub-frame and a second sub-frame accommodate selective ephemeris data. The third sub-frame accommodates a text message including almanac data optionally, ionospheric data, coordinated universal time (UTC) data, textual data optionally, and any combination thereof. A signal generation system (SGS) in the system selectively groups the almanac data, the ionospheric data, and the UTC data, and selectively transmits the navigation data with the almanac data or free of the almanac data in the navigation data structure to the satellite navigation receiver. The signal generation system also staggers the navigation data in each sub-frame into a first portion and a second portion for parallelly transmitting the navigation data over a first carrier frequency and a second carrier frequency in reduced time.

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: The present invention relates to a method for improving Time To First Fix, TTFF, sensitivity and accuracy, wherein a Global Navigation Satellite System, GNSS, positioning device (15), communicates with a Core Service (11) in a User Equipment (16), U—the GNSS positioning device acquires (23) GNSS satellite signals and navigation data and based on said signals/data determines a position within TTFF,—the Core Service detects (24) user data indicating specific user behaviours and initiates said determination of position based on said user data. The present invention also relates to a Core Service, a Global Navigation Satellite System, GNSS, positioning device, a Radio Module and a User Equipment, UE, adapted for the same purpose.

Abstract: A method and an apparatus for acquiring a signal of a global navigation satellite system (GNSS) are provided. The method includes: performing a first satellite signal acquiring operation based on an initially set Doppler frequency search start value and an initially set Doppler frequency search interval value; and changing the initially set Doppler frequency search start value and performing a second satellite signal acquiring operation when a satellite signal is not found through the first satellite signal acquiring operation.

Abstract: A technique for reducing the dwell time in acquiring a satellite signal is provided. The technique minimizes the dwell time in searching for a satellite signal in cells of a search space by comparing the peak-power-to-average ratio (PAPR) to one or more thresholds at one or more intermediate points during the search in a code phase/Doppler frequency bin. The comparison is then used to determine whether to continue the search in a current code phase/Doppler frequency bin or to continue to the next code phase/Doppler frequency bin.

Abstract: A reception apparatus includes a first determination unit to determine whether a state exists in which timing information and six orbital elements information can be obtained from GPS signals transmitted by only two GPS satellites. When the state exists, a calculation unit calculates a trajectory line having a predetermined width on a surface of the earth, based on the GPS signals transmitted by the two satellites. A second determination unit determines whether the trajectory line traverses a district of use stored by the apparatus. A time correcting unit obtains a current time using the obtained timing information, by correcting the timing information based on a time zone corresponding to the district of use, when the trajectory line traverses the district of use. The time correcting unit does not obtain the current time using the obtained timing information when the trajectory line does not traverse the district of use.

Abstract: Described are systems and methods for time synching to a network in an environment that contains obstructions disposed between a receiver component and a transmitting device of the network. In particular, an adaptive masking approach and an outage approach may be used to maintain time synchronization to the network. The adaptive masking approach may be used to track satellites above predefined elevation angles that correspond to the obstructions. The outage approach may be used to maintain time synchronization when the transmitting device of the network is not in view of the receiver component.

Abstract: Described are systems and methods for time synching.

Abstract: Methods, systems and devices are provided for operating a GPS engine in an active geofence monitoring state for no more than a first QoS period to obtain a first GPS fix. The GPS engine may also be set to operate in the active geofence monitoring state for no more than a second lower QoS period to obtain a second GPS fix in response to determining the first GPS fix was not obtained. The method may determine whether a geofence breach is detected in response to determining the GPS engine obtained the first GPS fix. The GPS engine may be set to operate in the active geofence monitoring state for no more than the second QoS period to obtain the second GPS fix in response to determining the geofence breach is not detected. The GPS engine may thus operate in the active geofence monitoring state to obtain the second GPS fix.

Abstract: A system and method for asset tracking configuration of a mobile terminal. A mobile terminal can be designed to enable a remote determination of an asset position. In one embodiment, the mobile terminal can include a configured function that enables the mobile terminal to reconfigure mobile terminal operation (e.g., activation of a GPS engine).

Abstract: A satellite navigation receiver and method for enhancing time to first fix are provided. The receiver comprises a radio frequency (RF) translator, correlator blocks, and a navigation data processor. The RF translator conditions navigation signals over carrier frequencies. The correlator blocks comprise a predetermined number of correlator channels configured for the carrier frequencies. The predetermined number of correlator channels is divided for parallel collection of sub-frames of navigation data across one or more operation service codes. The sub-frames of navigation data are collected across one or more operation service codes and on one of the carrier frequencies. The sub-frames of navigation data are collected across the carrier frequencies and on one of the operation service codes. The sub-frames of navigation data are collected across the carrier frequencies and across the operation service codes.

Abstract: A GNSS system operates intermittently and has adaptive activity and sleep time in order to reduce power consumption. The GNSS system provides an enhanced estimate of its position in the absence of GNSS signals of sufficient strength. The user's activity and behavior is modeled and used to improve performance, response time, and power consumption of the GNSS system. The user model is based, in part, on the received GNSS signals, a history of the user's positions, velocity, time, and inputs from other sensors disposed in the GNSS system, as well as data related to the network. During each activity time, the GNSS receiver performs either tracking, or acquisition followed by tracking The GNSS receiver supports both normal acquisition as well as low-power acquisition.

Abstract: A piezoelectric oscillator includes: a piezoelectric resonator; a storage unit that stores temperature compensation data used for specifying frequency-temperature characteristics of the piezoelectric resonator therein; a temperature compensation circuit; a voltage-controlled oscillation circuit that oscillates the piezoelectric resonator and controls an oscillation frequency of the piezoelectric resonator based on an oscillation control voltage; and a power source control unit that controls so as to supply a power source voltage to the temperature compensation circuit or so as not to supply the power source voltage to at least a part of the temperature compensation circuit based on a control signal transmitted from the outside, wherein the temperature compensation voltage is supplied as the oscillation control voltage to the voltage-controlled oscillation circuit in synchronization with a period during which the power source voltage is supplied to the temperature compensation circuit.

Abstract: A satellite signal tracking method includes: detecting a situation of movement; calculating an error of the detection; and setting a loop bandwidth of a tracking filter, which is used to track a satellite signal received from a positioning satellite and of which the loop bandwidth can be changed, using the detection result and the calculated error.

Abstract: A method and an integrated circuit to improve sensitivity of decoding time of a GNSS receiver are disclosed. A plurality of estimates of states of an encoder for one or more instances of a time counter is maintained. A signal comprising a plurality of data bits corresponding to an instance of the time counter is detected and at least one augmented state for each estimate of states of the encoder is determined. A corresponding augmented state for successive instances of the time counter is predicted and an augmented branch metric for each of the at least one augmented state is computed. A path metric for the each estimate is updated based on the augmented branch metric for each of the at least one augmented state and a time counter value is determined based on the path metric for the each estimate.

Abstract: Updates to an AFC loop can be performed to provide high-sensitivity tracking. A 20 ms update interval and PDI=10 ms is used for every other update. A setting is used for each update between the 20 ms updates. Notably, the setting uses PDI=5 ms. The setting can include first, second, and third cross-dot pairs associated with a first bit, a second bit, and a cross-bit boundary between the first and second bits, respectively. A sum of these pairs can be scaled down when the signal strength is below a predetermined threshold. In another embodiment, the setting can include a first cross-dot pair associated with a first bit and a second cross-dot pair associated with a second bit. A sum of these pairs can also be scaled down when signal strength is below a predetermined threshold.

Abstract: A system and methods for reducing navigation satellite receiver power usage are presented. A wireless signal is received at a portable electronic device in a signal environment. At signal characteristic of the wireless signal at the portable electronic device is measured in the signal environment. An estimated signal strength of the wireless signal in the signal environment is estimated based on the signal characteristic. The estimated signal strength is compared to an expected signal strength of the wireless signal to calculate an estimated signal-strength-change relative to the expected signal strength. A GNSS signal is tracked at the portable electronic device, if the estimated signal-strength-change indicates an expected GNSS signal attenuation is lower than a signal attenuation threshold.

Abstract: Signal acquisition assistance data is obtained for receiving devices such as wireless position assisted location devices seeking signals from any source, such as satellite vehicles and base stations. The data may be obtained from previously acquired data, based upon evaluation of changes in parameters such as time and location that may jeopardize validity. In some cases the data may be adjusted for the changes in parameters. Refined data may be calculated by a receiver using partial measurements of signal sets, particularly if the acquisition assistance data provided by a remote entity includes more distinct parameters than have typically been provided. New data need not be obtained until the validity of previous data expires due to limitations upon temporal extrapolation using Doppler coefficients, unless mobile station movement that cannot be compensated is detected, and jeopardizes validity of the previous data.

Abstract: The description relates to mobile device location. One example can identify global navigation satellite system (GNSS) satellites expected to be in line-of-sight of a mobile device. This example can detect differences between received GNSS data signals and expected GNSS data signals from the expected GNSS satellites. The example can also determine a direction from the mobile device of an obstruction that is causing at least some of the detected differences.

Abstract: Method, apparatus, and programs for synchronizing navigation data. First synchronization information is obtained from a receiver. The first synchronization information was used for synchronizing first navigation data received by the receiver from a navigation device. A sending time of second navigation data sent from the navigation device is then determined based on the first synchronization information. Second synchronization information is computed based on the sending time of the navigation data. The second synchronization information is used for synchronizing the second navigation data.

Abstract: System and method for locating a satellite signal receiver are disclosed. The system includes a channel opening module, a signal processing module, and a positioning module. The channel opening module is configured for opening a predetermined number of channels based on a priority schedule. The signal processing module is configured for capturing and tracking satellite signals via the opened channels, and demodulating the tracked satellite signals to obtain corresponding satellite data. The positioning module is configured for determining a position of the satellite signal receiver based on the satellite data.

Abstract: An offset estimator (e.g., a time delay, a spatial image offset, etc.) makes use of a transform approach (e.g., using Fast Fourier Transforms). The sparse nature of a cross-correlation is exploited by limiting the computation required in either or both of the forward and inverse transforms. For example, only a subset of the transform values (e.g., a regular subsampling of the values) is used. In some examples, an inverse transform yields a time aliased version of the cross-correlation. Further processing then identifies the most likely offset of the original signals by considering offsets that are consistent with the aliased output.

Abstract: Method, apparatus, and programs for synchronizing navigation data. Data synchronization is established between a receiver and a navigation device based on matching of a header of navigation data. The receiver receives the navigation data from the navigation device. If, subsequently, the data synchronization is interrupted, information related to the data synchronization from the receiver is retrieved. The data synchronization is then re-established between the receiver and the navigation device based on the retrieved information.

Abstract: An apparatus and method for processing a navigation signal are provided. When a navigation signal is received and processed, a search range associated with signal processing may be reduced by directly computing a clock offset of a receiving terminal, and accordingly it is possible to reduce an operation amount associated with the signal processing, and an amount of a power consumed by the receiving terminal. Additionally, due to a reduction in the search range, it is also possible to reduce a time required to acquire a signal.

Abstract: In embodiments of sync feedback for time to first fix (TTFF), satellite data signals are received from which a geographic position of a positioning-system device can be determined. The satellite data signals each include a time reference and ephemeris data that indicates an orbital position of a satellite. A sync feedback is generated that includes a time-free position fix determined from a satellite data signal before bit sync and/or frame sync of the satellite data signal are obtained. The sync feedback is then utilized as a feedback input to determine the bit sync and/or the frame sync of the satellite data signal.

Abstract: Techniques are provided to quickly estimate a temporal shift of a GPS signal based on an analysis of a GLONASS signal. The shift can be a result of applied leap-second adjustments affecting GLONASS signals but not GPS signals. By identifying this shift, GPS and GLONASS signals can be considered together in order to estimate locations. The temporal shift can be determined, e.g., by estimating a separation between a GPS-signal frame feature (e.g., frame onset) and a GLONASS-signal frame feature (e.g., frame onset), or identifying coinciding frame features (e.g., a GPS-signal subframe coinciding with a GLONASS-signal string number). The techniques allow the temporal shift to be estimated based on an analysis of just a portion of the GPS-signal and GLONASS-signal frames, such that a speed of location estimations can be improved.

Abstract: Some implementations provide low power reduced sampling of global positioning system (GPS) locations. A server may be configured to assist a mobile device in determining a location from a plurality of GPS signal samples and corresponding time stamps provided by the mobile device, such as by identifying a set of possible reference locations, which may be used to calculate a location of the mobile device. In another example, the mobile device may sample GPS signals using a GPS receiver, compress the samples, and provide the compressed samples to the server for processing.

Abstract: Sub-microsecond time transfer in a GPS/GNSS receiver using a weak GPS/GNSS signal is provided. The digitized complex baseband signal and the generated PN code are cross-correlated for each code period so as to output a complex correlation value at each code epoch of the generated PN code, where a sequence of the output correlation values form a data stream representing the navigation message. Bit synchronization generates bit sync pulses at bit boundaries. The location of a target segment having a known sequence at a known bit location in the navigation message is detected by searching through a plurality of subframes and accumulating search results for the plurality of subframes. Transmission time of the target segment is determined from the detected location of the target segment, with a certain time ambiguity. Accurate local time is determined by solving the time ambiguity using approximate time obtained from an external source.

Abstract: The present invention provides methods of performing GNSS receivers' satellite signal acquisition and TTFF while taking advantage of SBAS signals. Due to a SBAS satellite's geostationary position and typically strong signal, the SBAS satellite signal can be acquired more quickly than a GPS satellite signal. Once a SBAS satellite signal is acquired the Doppler frequency search uncertainty may be reduced for remaining GNSS satellites which are to be acquired. Furthermore, a satellite search list may be optimized to search for satellites close to the line of sight (LOS) of the SBAS satellite for which a signal has been acquired, in receiver “warm” and “hot” start modes. Moreover, since a SBAS signal sub-frame is only one second long, which is shorter than six seconds for a GPS signal sub-frame, synchronization of the SBAS signal sub-frame may be achieved faster than for GPS signals. With aided time information, a receiver may compute the absolute time of week (TOW) from a sub-frame synchronized SBAS signal.

Abstract: Enhancing search capacity of Global Navigation Satellite System (GNSS) receivers. A method for searching satellite signals in a receiver includes performing a plurality of searches sequentially. The method also includes storing a result from each search of the plurality of searches in a consecutive section of a memory. Further, the method includes detecting free sections in the memory. The method also includes concatenating the free sections in the memory to yield a concatenated free section. Moreover, the method includes allocating the concatenated free section for performing an additional search.

Abstract: A GNSS receiver reduces the time to first fix by utilizing the properties of existing radiated signals of opportunity, such as AM or FM radio signals, television signals and so forth, to reduce the uncertainties associated with oscillator frequency and phase, and further utilizing an Almanac and battery backed-up date and time to determine the satellites in view and reduce the uncertainties associated with Doppler. The receiver may use multiple signals of opportunity to determine the city or local area in which the receiver is located based on the set of frequencies of the signals, and also to reduce search uncertainties for oscillator frequency by estimating an offset based on the differences between the frequencies of the respective signals of opportunity at the receiver and the nominal broadcast frequencies of the signals.

Abstract: A navigation bit boundary determination apparatus and a method therefor. In one example, the navigation bit boundary determination apparatus includes a satellite signal receiving module, a position receiving and clock calibration module, a detection module, a first calculation module, a second calculation module, and a determination module. The satellite signal receiving module is configured to receive a satellite signal from a satellite and record a local receiving time of the satellite signal. The position receiving and clock calibration module is configured to receive a time signal and a position of the navigation bit boundary determination apparatus. The detection module is configured to detect if ephemeris information of the satellite is available. The first calculation module is configured to calculate a coordinate of the satellite. The second calculation module is configured to calculate a transmitting time for the satellite signal.

Abstract: Apparatus comprises: a first correlator configured to correlate a first signal component with a first code to provide a first output, said first signal component having a carrier frequency and data; a second correlator configured to correlate a second signal component with a second code to provide a second output, said second signal component having the same carrier frequency as the first signal component and the same data as the first signal component, said data on the second signal component being delayed with respect to the data on the first signal component; and a processor configured to process the first and second outputs, said data on said first output being aligned with the second output to provide frequency information about said carrier.

Abstract: Various techniques are provided for obtaining a precise absolute time using a satellite system. In one example, a method of transferring precise absolute time from a satellite to a device includes receiving data from a messaging channel, wherein the data has a frame structure. The method also includes using the data to identify the satellite and a position of the satellite, correcting for signal time of flight using the satellite identity and the position, and using the data as a time reference to align a receiver clock to the frame structure. The method also includes, with the receiver clock aligned to the frame structure, receiving a precision time signal from the satellite, wherein the precision time signal comprises a periodic repeating code. The method also includes determining a timing phase of the code and using the timing phase to determine a precise absolute time.