System and Method Using Adjunct Signals to Increase Wideband Receiver Performance
AssigneeThe Boeing Company
InventorGary A. Ray
Life of this patent
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Abstract
Systems and methods which use adjunct signals from a remote highly stable clock to enhance performance of a digital wideband receiver equipped with a less stable local clock system. The digital wideband receiver includes an analog-to-digital converter (ADC) and an adjunct receiver system connected to the output of the ADC. The adjunct receiver system includes matched filters and circuitry configured to generate an interpolation coefficient vector based on the matched filter outputs. The adjunct receiver system further includes an interpolating filter which is configured to remove jitter from the digitized samples output by the ADC using the interpolation coefficient vector.
Claims20
A wideband receiver comprising:
- an antenna;
- a local clock configured to generate clock signals;
- an analog-to-digital converter connected and configured to convert analog signals received by the antenna into digital samples in accordance with the clock signals;
- an adjunct processing module connected and configured to match filter digital samples output by the analog-to-digital converter and derive an interpolation coefficient vector from the clock signals and match-filtered digital samples;
- delay circuitry connected and configured to delay the digital samples output by the analog-to-digital converter and received directly by the delay circuitry without match filtering;
- an interpolation filter connected and configured to convolve digital samples output by the delay circuitry with the interpolation coefficient vector output by the adjunct processing module to remove local clock-induced jitter from the digital samples output by the delay circuitry;
- and
- a wideband receiver processing module connected and configured to process digital samples received from the interpolation filter.
A system comprising a wideband receiver system, a plurality of transmitter systems, and an adjunct transmitter system,
- wherein each transmitter system comprises a respective waveform generator and a respective transmit antenna configured to transmit a respective signal of interest based on waveforms generated by the respective waveform generator;
- wherein the adjunct transmitter system comprises a remote clock having a high stability, an adjunct waveform generator, and an adjunct transmit antenna configured to transmit adjunct signals based on adjunct waveforms generated by the adjunct waveform generator;
- and
- wherein the wideband receiver system comprises:
- a receive antenna;
- a local clock configured to generate clock signals and having a stability lower than the high stability of the remote clock;
- an analog-to-digital converter connected and configured to convert adjunct signals and signals of interest received by the receive antenna from the transmit antenna and adjunct transmit antenna into digital samples in accordance with the clock signals from the local clock;
- an adjunct processing module connected and configured to match filter digital samples of the adjunct signals and derive an interpolation coefficient vector from the clock signals and match-filtered digital samples;
- delay circuitry connected and configured to delay the digital samples output by the analog-to-digital converter and received directly by the delay circuitry without match filtering;
- an interpolation filter connected and configured to convolve digital samples output by the delay circuitry with the interpolation coefficient vector output by the adjunct processing module to remove local clock-induced jitter from the digital samples output by the delay circuitry;
- and
- a wideband receiver processing module connected and configured to process digital samples received from the interpolation filter.
A method of operating a wideband receiver, the method comprising:
- receiving analog signals using an antenna;
- generating clock signals using a local clock;
- converting analog signals received by the antenna into digital samples in accordance with the clock signals generated by the local clock;
- match filtering digital samples to extract digital samples of adjunct signals having known frequencies;
- deriving an interpolation coefficient vector from the clock signals and match-filtered digital samples;
- delaying digital samples not match filtered;
- convolving delayed digital samples with the interpolation coefficient vector to remove local clock-induced jitter from the delayed digital samples;
- and
- processing digital samples from which local clock-induced jitter has been removed.
Dependencies are inferred from the claim text.