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US 10,958,302 B1Granted
Signal cueing using an IIR filter array with inverted state tree
AssigneeThe Boeing Company
InventorGary A. Ray
Life of this patent
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Abstract
Efficient and low-latency cueing means for initiating and updating a process of signal detection and separation in a wideband receiver. The method uses an array of IIR filters that feed an inverted state tree. The inverted state tree provides the directions for separating, detecting, and tracking multiple simultaneous signals that are being received. These signals could be either radar or communications signals and are of widely differing frequencies, bandwidths, and other characteristics. The directions are sent by the cueing system to a set of tunable tracking filters and continuously updated so that the set of tracking filters produce noise-reduced, separated signals on their outputs representing the various simultaneous incoming signals.
Claims20
A method for cueing signals comprising:
- transducing electromagnetic radiation carrying a repetitive signal into an analog electrical signal;
- converting the analog electrical signal into digital signal samples;
- inputting the digital signal samples to first and second filters configured to pass first and second bandwidths respectively which are partially overlapping;
- outputting first filtered signal samples from the first filter and second filtered signal samples from the second filter in response to inputting the digital signal samples;
- processing the first and second filtered signal samples to generate digital data representing an estimated frequency and an estimated bandwidth;
- processing the first and second filtered signal samples to generate digital data representing an estimated pre-detection metric;
- determining that the estimated pre-detection metric is greater than a specified threshold;
- generating filter coefficients for an available tunable filter which are functions of the estimated frequency and the estimated bandwidth following a determination that the estimated pre-detection metric is greater than the specified threshold;
- and
- tuning the available tunable filter in accordance with the filter coefficients.
7 more elements
A method for cueing signals comprising:
- transducing electromagnetic radiation carrying a repetitive signal into an analog electrical signal;
- converting the analog electrical signal into digital signal samples;
- inputting the digital signal samples to first, second, and third filters configured to pass first, second, and third bandwidths respectively, wherein the first and second bandwidths are partially overlapping, the second and third bandwidths are partially overlapping, and the first and third bandwidths are not partially overlapping;
- outputting first, second, and third filtered signal samples from the first, second, and third filters respectively in response to inputting the digital signal samples;
- processing the first and second filtered signal samples to generate digital data representing a first estimated frequency and a first estimated bandwidth;
- processing the first and second filtered signal samples to generate digital data representing a first estimated pre-detection metric;
- determining that the first estimated pre-detection metric is greater than a specified threshold;
- processing the second and third filtered signal samples to generate digital data representing a second estimated frequency and a second estimated bandwidth;
- processing the second and third filtered signal samples to generate digital data representing a second estimated pre-detection metric;
- determining that the second estimated pre-detection metric is greater than the specified threshold;
- joining the first and second estimated bandwidths to form a wider bandwidth that is a union of first and second estimated bandwidths;
- calculating a center frequency of the wider bandwidth;
- generating filter coefficients for a tunable filter which are functions of the calculated center frequency and the wider bandwidth following a determination that the first and second estimated pre-detection metrics are greater than the specified threshold;
- and
- tuning the tunable filter in accordance with the filter coefficients.
12 more elements
A signal processing system comprising:
- a sensor configured to transduce electromagnetic radiation carrying a repetitive signal into an analog electrical signal;
- an analog-to-digital converter configured to convert the analog electrical signal into signal samples;
- first and second filters connected to receive the signal samples and configured to pass first and second bandwidths respectively which are partially overlapping;
- a first signal frequency/bandwidth estimator connected to receive first and second filtered signal samples from the first and second filters and configured to process filtered signal samples from two filters to generate digital data representing a first estimated frequency and a first estimated bandwidth;
- a first pre-detection estimator connected to receive first and second filtered signal samples from the first and second filters and configured to process filtered signal samples from two filters to generate digital data representing a first estimated pre-detection metric;
- a plurality of signal separation and tracking channels, each signal separation and tracking channel comprising a respective tunable filter;
- a signal separation and tracking controller configured to control tuning of the plurality of signal separation and tracking channels;
- and
- a first root node connected to receive the first estimated frequency and the first estimated bandwidth from the first signal frequency/bandwidth estimator and receive the first estimated pre-detection metric from the first pre-detection estimator and communicate with the signal separation and tracking controller, wherein the first root node is configured to not send a request for available channel to the signal separation and tracking controller if the first estimated pre-detection metric does not indicate that the signal samples were derived from a repetitive signal.
6 more elements
A signal cueing system comprising:
- first, second, and third filters configured to pass first, second, and third bandwidths, respectively, wherein the first and second bandwidths are partially overlapping, the second and third bandwidths are partially overlapping, and the first and third bandwidths are not partially overlapping;
- a first signal frequency/bandwidth estimator connected to receive first and second filtered signal samples from the first and second filters and configured to process filtered signal samples from two filters to generate digital data representing a first estimated frequency and a first estimated bandwidth;
- a first pre-detection estimator connected to receive first and second filtered signal samples from the first and second filters and configured to process filtered signal samples from two filters to generate digital data representing a first estimated pre-detection metric;
- a first root node connected to receive the first estimated frequency and the first estimated bandwidth from the first signal frequency/bandwidth estimator and receive the first estimated pre-detection metric from the first pre-detection estimator, wherein the first root node is configured to not generate a request for available channel if the first estimated pre-detection metric does not indicate that the signal samples were derived from a repetitive signal;
- a second signal frequency/bandwidth estimator connected to receive second and the filtered signal samples from the second and third filters and configured to process filtered signal samples from two filters to generate digital data representing a second estimated frequency and a second estimated bandwidth;
- a second pre-detection estimator connected to receive second and third filtered signal samples from the second and third filters and configured to process filtered signal samples from two filters to generate digital data representing a second estimated pre-detection metric;
- a second root node connected to receive the second estimated frequency and the second estimated bandwidth from the second signal frequency/bandwidth estimator and receive the second estimated pre-detection metric from the second pre-detection estimator, wherein the second root node is configured to not generate a request for available channel to the signal separation and tracking controller if the second estimated pre-detection metric does not indicate that the signal samples were derived from a repetitive signal;
- and
- a non-root node connected to receive the state values representing the first estimated frequency, the first estimated bandwidth, and the first estimated pre-detection metric from the first root node and the second estimated frequency, the second estimated bandwidth, and the second pre-detection metric from the second root node, wherein the non-root node is configured to calculate and output state values representing a third estimated frequency and a third estimated bandwidth in response to the first and second estimated bandwidths being adjacent or partially overlapping, the third estimated pre-detection metric being a union of the first and second bandwidths, and further configured to not generate a request for available channel to the signal separation and tracking controller if the third estimated pre-detection metric does not indicate that the signal samples were derived from a repetitive signal.
6 more elements
Dependencies are inferred from the claim text.