Trimble Navigation Limited

Samsung Electronics Co., Ltd.

Sirf Technology, Inc.

Csr Technology Inc.

Cambridge Silicon Radio Limited

Csr Technology Holdings Inc.

Sirf Technology Holdings, Inc.

Gary R Lennen

William Kerry Keal

Makarand Phatak

Scott R Smith

Andy Milota

Murray Robert Jarvis

Daniel Babitch

Henry D Falk

Brian G Westfall

Kreg A Martin

Wilfred Hand

A Global Navigation Satellite System (GNSS) receiver includes a wideband signal correlator and a multipath mitigator. The wideband signal correlator generates wideband correlation signals of at least one of a plurality of GNSS signals with respect to corresponding locally generated code replica signals in which a bandwidth of the wideband signal correlation module is at least about 20 MHz. The multipath mitigator determines a Line of Sight (LOS) signal from the wideband correlation signals. The GNNS receiver may include a narrowband signal correlator to generate narrowband correlation signals of the at least one GNSS signal with respect to corresponding locally generated code replica signals in which a bandwidth of the narrowband signal correlation module is less than about 6 MHz. The multipath mitigator further corrects a range and range-rate measurement generated from the narrowband correlation signals based on a code phase and a carrier estimated based on the LOS signal.

Method and apparatus for improving GNSS accuracy via path identification

An apparatus, a method, a method of manufacturing an apparatus, and a method of constructing an integrated circuit are provided. The apparatus includes a memory; and a processor configured to acquire K values with N peaks, where K and N are integers; select J of the N peaks and include the J peaks in track, where J is an integer less than or equal to N; determine a metric using acquisition non-coherent summations (NCSs) and track NCSs of coherent correlations; determine to not abandon the measurement based on the metric; and form a measurement responsive to determining to not abandon.

System and method for improved GNSS sensitivity via combining acquisition and track correlation hypotheses

An electronic device, method and system for global navigation satellite system (GNSS) are herein disclosed. The electronic device includes an antenna configured to receive a satellite vehicle (SV) signal, and a processor configured to determine a carrier-to-noise density ratio (CNO) of the SV signal, compare the determined CNO of the SV signal with a threshold, and identify whether the SV signal is a true SV signal or a false SV signal when the determined CNO is less than the threshold.

Detection and mitigation of false global navigation satellite system tracks in the presence of locally generated interference

A method and an apparatus are provided for improving a carrier to noise density ratio (CNO) of a matched filter. A signal is received at a signal register of the matched filter. A local code is received at a local code register and a nulling register of the matched filter. An adder tree of the matched filter correlates the signal register and the local code register with respect to the nulling register to obtain a correlation result. The nulling register prevents high frequency samples of the signal register from affecting the correlation result.

Method and apparatus for TMBOC transmission with narrowband receivers

A system and method for providing asymmetrical filtering to improve performance in the presence of wideband interference is herein disclosed. According to one embodiment, a method for a global navigation satellite system (GNSS) receiver includes detecting wideband interference in a received target GNSS signal, and applying an asymmetric filter to the received target GNSS signal to mitigate the detected wideband interference.

Asymmetrical filtering to improve GNSS performance in presence of wideband interference

Systems, methods and apparatuses for generating long coherent integrations of received global navigation satellite system (GNSS) signals are described. One method includes generating coherent 1 second I/Q correlations by at least two stages of summation starting with 1 millisecond correlated I/Q signal samples. Intermediate stage coherent I/Q correlations may be modified based on, for example, lack of carrier phase lock and/or the carrier signal-to-noise density (C/N). Such modifications include phase rotation. Energy/power amplitudes calculated from the coherent 1 second I/Q correlations may be used for improving multipath mitigation, the signal-to-noise ratio (SNR), and other GNSS receiver operations and functions.

GNSS receiver performance improvement via long coherent integration

A system and method for multipath estimation and mitigation is disclosed. In some embodiments, the method includes performing a first weight estimation operation for a first number of multipath components of a received correlation, calculating a remaining error energy by subtracting a sum of estimated multipath components from the received correlation, determining whether a satisfaction criterion is met for the remaining error energy, and, in response to determining that the satisfaction criterion is not met, performing a second weight estimation operation for a second number of multipath components, the second number being greater than the first number.

Multipath mitigation for GNSS receivers

A method and system are herein provided. The method may include receiving a GNSS signal, determining a normalized correlation window of the GNSS signal, determining an early sidelobe lock (E), a late sidelobe lock value (L), and main sidelobe lock (M) value based on the normalized correlation window, determining an early sidelobe lock (E), a late sidelobe lock value (L), and main sidelobe lock (M) value based on the normalized correlation window, and determining an early sidelobe lock (E), a late sidelobe lock value (L), and main sidelobe lock (M) value based on the normalized correlation window.

System and method for providing global navigation satellite system (GNSS) signal processing in multipath environment

An apparatus, a method, a method of manufacturing an apparatus, and a method of constructing an integrated circuit are provided. The apparatus includes a memory and a processor configured to conduct acquisition of K values with N peaks, where K and N are integers; store the K values in the memory; select J of the N peaks and include the J peaks in track, where J is an integer less than or equal to N; combine acquisition and track non-coherent summations (NCSs) of coherent correlations in a metric; and form a measurement unless the metric indicates that the measurement should be abandoned.

An apparatus and a method. The apparatus includes an interference mitigation processor, including an input, and an output, the interference mitigation processor configured to sum n msec received correlators over m msec, and analyze the n msec correlators to reduce interference. The method includes summing, by an interference mitigation processor, n msec received correlators over m msec; and analyzing, by an interference mitigation processor, the n msec correlators to reduce interference.

System and method for improved data decoding, tracking, and other receiver functions in the presence of interference

Apparatuses and methods of manufacturing same, systems, and methods are described for combining received and correlated Global Navigation Satellite System (GNSS) signals and using the combined signal for improving GNSS reception in, inter alia, challenging environments. In one aspect, a first correlated GNSS signal and a second correlated GNSS signal are stored and then combined, and the combined signal is used to adjust reception of the first GNSS signal and/or the second GNSS signal. If the first and second correlated GNSS signals are stored by unequal time periods, time periods of one or both are added together until the total added first correlated GNSS signal is the same length of time as the total added second correlated GNSS signal. In order to properly combine the GNSS signals, gain/balancing factor(s) may be applied, the polarity of one or both may be flipped, etc.

System and method for combining signals for improved performance in challenging environment

Systems, methods and apparatuses for multipath mitigation in global navigation satellite system (GNSS) receivers are described. One method includes modifying the locally generated code in the GNSS receiver bit by bit in order to reduce offset peaks in the autocorrelation when receiving the satellite generated code signal. Such modified local codes may be pre-computed and stored or otherwise provided during reception. Moreover, the GNSS receiver may select whether or not to use the modified local code or the standard local code based on a selection criteria. Furthermore, multiple modified version of the same local code may be generated and/or stored in order to provide differing performance levels.

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Cupertino, CA, United States of America

Gary R Lennen