Methods and apparatus for minimum computation phase demodulation
AssigneeHoneywell International Inc.
InventorsJames R. Hager, Lavell Jordan, Todd R. Burlet, Curtis J. Petrich
Life of this patent
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Abstract
A filter, includes a first order band pass filter configured to process non-zero amplitude gated radar return samples and process a portion of received zero amplitude return samples. The filter also calculates past filter outputs based on filter outputs generated during previous non-zero gated radar return samples.
Claims27
A filter, said filter comprising a first order band pass filter, said filter configured to process non-zero amplitude gated radar return samples, said filter further configured to process only a portion of received zero amplitude gated radar return samples, said filter further configured to calculate past filter outputs for pending non-zero amplitude gated radar return samples based on filter outputs generated during previous non-zero gated radar return samples.
A method for reducing computations in a band pass filter, the filter receiving non-zero amplitude gated radar return samples and zero amplitude gated radar return samples, said method comprising:
- sampling the radar return samples with the band pass filter;
- processing non-zero amplitude gated radar return samples;
- ignoring a portion of zero amplitude gated radar return samples;
- and
- calculating past outputs for the processing of non-zero amplitude gated radar return samples based on previous filter outputs generated when processing previous non-zero amplitude gated radar return samples.
A method for processing radar return data, comprising:
- sampling the radar data from each of the receiver channels;
- filtering the samples with a filter configured to process non-zero amplitude gated radar return samples, configured to not process a portion of zero amplitude gated radar return samples, and further configured to calculate past outputs based on filter outputs generated during the processing of previous non-zero amplitude gated radar return samples;
- converting the processed samples to a doppler frequency;
- applying a band pass filter to the doppler frequency signals, the filter centered at the doppler frequency;
- and
- determining a phase relationship between the receiver channels.
A radar signal processing circuit comprising:
- a radar gate correlation circuit configured to sample radar data at a sampling rate;
- a correlation bass pass filter configured to process non-zero gated radar return samples, configured to not process a portion of zero amplitude gated radar return samples, and further configured to calculate past outputs based on filter outputs generated during processing of at least one previous non-zero gated radar return sample;
- a mixer configured to down sample an in-phase component and a quadrature component of the filtered signal to a doppler frequency;
- and
- a band pass filter centered on the doppler frequency.
A filter, said filter comprising a digital band pass filter including an input, an output, and a sample clock input at a frequency of fsample, said filter configured to:
- process non-zero input samples;
- process only a portion of zero amplitude input samples;
- and calculate past outputs for the processing of pending non-zero input samples based on filter outputs generated while processing previous non-zero input samples.
Dependencies are inferred from the claim text.