Deere + Company

David M Li

Richard Gerald Keegan

Wei Yu

Mark Phillip Kaplan

Brian C Goodrich

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 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.

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Harbor City, CA, United States of America

David M Li