Deere + Company

Rf Micro Devices, Inc.

Magnavox Government and Industrial Electronics Company

Leica Geosystems Ag

Auburn University

Raytheon Company

Navcom Technology, Inc.

Magnavox Electronic Systems Company

Norbelle LLC

L & H Company, Inc.

Richard Gerald Keegan

Wei Yu

Mark Phillip Kaplan

David M Li

Ronald R Hatch

Jerry Eugene Knight

Richard Najarian

Brian C Goodrich

Charles Robert Cahn

David M Bevly

Stephen F Rounds

Thomas A Stansell, Jr

Scott M Martin

Charles P Norman

James M Hume

Andreas Warloe

Darin E Bartholomew

Andrew M Hautzik

Norman Mohi

Mark Scislowski

Kevin S Judge

Gary V Jones

Jon E Maenpa

Wayne H Cox

Eugene Jerry Knight

Steven Francis Colborne

Steve Francis Colborne

Robert Olivier

James R Hume

A demodulator comprises a first-stage carrier demodulator and a second-stage carrier demodulator. The first-stage carrier demodulator is configured to remove or compensate for the tracking error in the baseband signal, where the tracking error comprises aggregate, channel tracking error of carrier phase for the same received band, sub-band, (baseband) GNSS satellite channel, or set GNSS channels. The second stage carrier demodulator is configured to remove or strip a carrier signal component without any unwanted image or carrier-related frequency artifacts and to prepare for correlation-based decoding or demodulation of the encoded baseband signal by the correlators. First correlators are configured to determine correlations for code phase tracking loop, where the code phase tracking loop is configured to estimate a corresponding code error component of the tracking error for the code local oscillator for a respective channel. Secondary correlators are configured to determine correlations for a carrier phase tracking loop, where the carrier phase tracking loop configured to estimate a corresponding aggregate feedback error for multiple channels or a set of channels.

Satellite navigation receiver with aggregate channel digital baseband processing

A wideband interference mitigation module is coupled to an output of a primary downconverter to process the digital intermediate frequency signal. A selective filtering module is associated with a secondary downconverter that comprises a digital harmonic-resistant translator. The selective filtering module comprises: (a) a low-pass filter that is configured as an anti-aliasing digital filter consistent with a target receive bandwidth to suppress aliasing associated with the analog-to-digital conversion, and (b) narrow band rejection filter to filter the digital baseband signal to reduce or to mitigate electromagnetic interference, where the narrow band rejection filter is configured for adaptive control responsive to detection by the wideband interference mitigation module of certain interference in the received radio frequency signal.

Multi-constellation, multi-frequency GNSS system for interference mitigation

A controller is configured to control the adaptive notch filter and to execute a search technique (e.g., artificial intelligence (AI) search technique) to converge on filter coefficients and to recursively adjust the filter coefficients of the adaptive notch filter in real time to adaptively adjust one or more filter characteristics (e.g., maximum notch depth or attenuation, bandwidth of notch, or general magnitude versus frequency response of notch).

Adaptive narrowband interference rejection for satellite navigation receiver

A navigation system for a mobile object generates navigation data for the mobile object based on satellite navigation signals received from a plurality of satellites and base data received from a stationary base station. The navigation data includes code phase estimates and carrier phase estimates for the plurality of satellites. The system computes position, velocity and time estimates for the mobile object in accordance with the code phase estimates and carrier phase estimates, and performs a navigation function for the mobile object in accordance with the position, velocity and time estimates. The system generates code phase estimates by performing a Vector Delay Locked Loop (VDLL) computation process that drives a code NCO for each channel of a plurality of channels, and generates carrier phase estimates for the plurality of satellites by performing a RTK Vector Phase Locked Loop computation process that drives a carrier NCO for each channel.

RTK vector phase locked loop architecture

A selective filtering module is arranged to filter or process the digital baseband signal consistent with a target receiving bandwidth, where the selective filtering module comprises a narrowband rejection filter and wide-band filter configured to reject an interference component that interferes with the received radio frequency signal. The narrowband rejection filter is configured to reject a first interference component, where the narrowband rejection filter comprises an adaptive notch filter (NF). The wide band rejection filter is configured to reject a second interference component in accordance with a pulse blanking technique. An electronic data processor is adapted to control one or more filter coefficients of narrowband rejection filter and the wide band rejection filter in accordance with one or more strategic filter control factors among ADC saturation, activation/deactivation of the notch filter, and a wide-band spectrum analysis.

Adaptive narrowband and wideband interference rejection for satellite navigation receiver

A method is provided for acquiring a signal from a satellite in a global navigation satellite system. The signal includes a pseudorandom code. The method includes, for each time period of a plurality of time periods: generating samples of the signal, segments of the samples of the signal are correlated with a local copy of the pseudorandom code, thereby producing correlation values for the time period. A discrete Fourier transform is performed using, as inputs, the correlation values for the respective time period, thereby producing a frequency representation of the correlation values for the time period. The frequency representations of the correlation values for the plurality of time periods are combined according to a data hypothesis. When a magnitude of the combined frequency representations meets predefined criteria, a frequency corresponding to the magnitude is selected as a tracking frequency for the satellite.

Methods and devices for global navigation satellite system (GNSS) signal acquisition

A system for navigating a mobile object generates satellite navigation data for the mobile object based on satellite navigation signals received from a plurality of satellites and base data received from a stationary base station. The satellite navigation data for the mobile object includes code phase estimates and carrier phase estimates for the plurality of satellites. The system computes position, velocity and time estimates for the mobile object in accordance with the code phase estimates and carrier phase estimates, and performs a navigation function for the mobile object in accordance with the computed position, velocity and time estimates for the mobile object. The system generates the code phase estimates by performing a Vector Delay Locked Loop (VDLL) computation process, and generates carrier phase estimates for the plurality of satellites including by performing a Real-Time-Kinematics Vector Phase Locked Loop (RTK-VPLL) computation process.

A multi-band satellite navigation receiver for carrier and code tracking using a fixed point sigma rho filter with improved stability is described. The receiver simplifies and speeds up the data processing in the filter to adaptively accommodate common information from aggregate bands and obtain the accurate position of the receiver in real time. The filter may utilize a standard deviation function and a cross correlation function while determining adaptive scale factors to ensure that the filter is stable and reliable.

Satellite navigation receiver with fixed point sigma rho filter

Satellite navigation receiver with fixed point sigma RHO filter

A data processor estimates the location of the receiver or estimated range from multicarrier signal. The data processor determines phase compensation data for each ranging subcarrier in the multipath signal. The phase compensation data comprises an adjustment to the estimated range based on a difference between an observed phase of the observed signal vector and a direct path phase of a direct path vector, where the direct path phase is estimated based on one or more prior measurements of a certain observed signal vector when an average amplitude of all (or a majority of) ranging subcarriers converge to substantially the same value.

Determining location of a receiver with a multi-subcarrier signal

A first estimator determines a coarse estimate of a time of arrival of at least one subcarrier of an OFDM-like multitone signals by adjusting the coarse estimate of the time of arrival in accordance with a code (first) correlation function. A second estimator determines a precise estimate of the time of arrival of at least one subcarrier of the OFDM-like multitone signals by adjusting the precise time of arrival to align the slope of the subcarrier phases of the OFDM-like multitone signals in accordance with a phase (second) correlation function and consistent with the coarse estimate of the time of arrival associated with the code correlation function. A data processor estimates the location of the receiver or estimated range based on the precise estimate.

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Palos Verdes Estates, CA, United States of America

Richard Gerald Keegan