Signal removal to examine a spectrum of another signal

• US 10,783,430 B2
• Filed: 09/26/2016
• Issued: 09/22/2020
• Est. Priority Date: 09/26/2016
• Status: Active Grant

• Current Assignee: HRL Laboratories LLC (The Boeing Co.), The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Wittenberg, Peter S., Petre, Peter, Rao, Shankar R.
• Primary Examiner(s): Starks, Wilbert L
• Application Number:
  US15/276,188
• Publication Number:
  US 20180089558A1
• Time in Patent Office: 1,457 Days
• Field of Search: None
• CPC Class Codes: G01R 23/167 with digital filters
• CPC Class Codes: G06F 17/16 Matrix or vector computation , e.g. matrix-matrix or matrix-vector multiplication, matrix factorization matrix transposition G06F7/78
• CPC Class Codes: G06N 3/044 Recurrent networks, e.g. Hopfield networks
• CPC Class Codes: G06N 3/06 Physical realisation, i.e. hardware implementation of neural networks, neurons or parts of neurons
• CPC Class Codes: G06N 3/065 Analogue means
• CPC Class Codes: G06N 3/084 Backpropagation, e.g. using gradient descent
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 3/19 with semiconductor devices only
• CPC Class Codes: H03H 17/0294 Variable filters; Programmable filters
• CPC Class Codes: H03H 2017/0081 of FIR filters
• CPC Class Codes: H03H 2017/009 of IIR filters
• CPC Class Codes: H03H 21/0012 Digital adaptive filters
• CPC Class Codes: H04B 1/0007 wherein the AD/DA conversion occurs at radiofrequency or intermediate frequency stage
• CPC Class Codes: H04B 1/123 using adaptive balancing or compensation means adaptive filter circuits and algorithms H03H

Abstract

A method for removing an extracted RF signal to examine a spectrum of at least one other RF signal includes receiving a mixture signal by an ADC. The mixture signal includes a plurality of separate signals from different signal sources. The mixture signal is digitized by the ADC. A first digitized signal and a second digitized signal are generated that are the same. The first digitized signal is delayed a predetermined time delay and the second digitized signal is processed in a neuromorphic signal processor to extract an extracted signal. The predetermined time delay corresponds to a delay embedding in the neuromorphic signal processor. A phase delay and amplitude of the extracted signal is adjusted based on a phase delay and amplitude of the first digitized signal. An adjusted extracted signal is cancelled from the first digitized signal to provide an input examination signal for examination.

Claims

1. A method for removing an extracted radio frequency (RF) signal to examine a spectrum of at least one other RF signal, comprising:

receiving a mixture signal by an analog-to-digital converter (ADC), the mixture signal comprising a plurality of separate source signals from different signal sources;

digitizing the mixture signal by the ADC and generating a first digitized signal and a second digitized signal, wherein the first digitized signal is the same as the second digitized signal;

delaying the first digitized signal by a predetermined time delay;

processing the second digitized signal in a neuromorphic signal processor to extract an extracted signal from the second digitized signal, wherein the predetermined time delay corresponds to a delay embedding in the neuromorphic signal processor;

adjusting a phase delay and amplitude of the extracted signal based on a phase delay and amplitude of the first digitized signal; and

cancelling an adjusted extracted signal from the first digitized signal to provide an input examination signal.

2. The method of claim 1, further comprising amplifying the mixture signal before the mixture signal is received by the ADC, wherein the mixture signal is amplified to a predetermined amplitude for sampling by the ADC.

3. The method of claim 1, further comprising determining the phase delay and amplitude of the extracted signal and the first digitized signal and generating an adjustment to the extracted signal based on the phase delay and amplitude of the first digitized signal.

4. The method of claim 3, wherein adjusting the phase delay and amplitude of the extracted signal comprises generating the adjusted extracted signal that is 180 degrees out of phase with the first digitized signal.

5. The method of claim 1, wherein processing the second digitized signal in the neuromorphic signal processor comprises:

receiving the second digitized signal by the neuromorphic signal processor;

generating a delay embedded mixture signal based on the second digitized signal;

linearly mapping the delay embedded mixture signal into a reservoir;

creating a multi-dimensional state-space representation of the mixture signal by combining the delay embedded mixture signal with a plurality of reservoir states;

identifying at least one of the separate source signals that collectively form the mixture signal based on the multi-dimensional state-space representation of the mixture signal, the at least one identified separate source signal being the extracted signal.

6. The method of claim 5, further comprising linearly mapping the multi-dimensional state-space representation to one or more nodes in an output layer to generate a set of pre-filtered signals.

7. The method of claim 6, further comprising identifying at least one of the separate source signals by adaptively filtering the pre-filtered signals.

8. The method of claim 7, wherein adaptively filtering the pre-filtered signals comprises passing the pre-filtered signals through a bank of adaptable filters, wherein each pre-filtered signal is fed into a unique filter in the bank of adaptable filters, each unique filter having an adaptable center frequency.

9. The method of claim 8, wherein the bank of adaptable filters comprises a plurality of finite impulse response (FIR) filters and a plurality of infinite impulse response (IIR) filters.

10. The method of claim 8, wherein the output layer comprises a set of output nodes and the reservoir comprises a plurality of processing nodes, each output node receiving a weighted output from each processing node as an input, and each output node summing a value of each input to produce an output of the output node.

11. The method of claim 10, wherein each output node in the output layer comprises a unique and adaptable set of output weights on its input connections, such that as one or more mixture signals are passed into the neuromorphic signal processor, the adaptable output weights are configured so that output from a given output node amplifies a subset of source signals while suppressing other source signals.

12. The method of claim 11, further comprising deriving an error signal based on an output from each adaptable filter, wherein the error signal is used to update the adaptable center frequency of the adaptable filter and update the adaptable output weights in the output layer.

13. A system for removing an extracted radio frequency (RF) signal to examine a spectrum of at least one other RF signal, comprising:

an analog-to-digital converter (ADC) for receiving a mixture signal, the mixture signal comprising a plurality of separate source signals from different signal sources, the ADC digitizes the mixture signal and generates a first digitized signal and a second digitized signal, wherein the first digitized signal is the same as the second digitized signal;

a delay circuit for delaying the first digitized signal by a predetermined time delay;

a neuromorphic signal processor for processing the second digitized signal to extract an extracted signal from the second digitized signal, wherein the predetermined time delay corresponds to a delay embedding in the neuromorphic signal processor;

a signal phase and amplitude adjustment module that adjusts the extracted signal based on a phase delay and amplitude of the first digitized signal; and

a summing junction for cancelling an adjusted extracted signal from the first digitized signal to provide an input examination signal.

14. The system of claim 13, further comprising an amplifier that amplifies the mixture signal before the mixture signal is received by the ADC, wherein the amplifier amplifies the mixture signal to a predetermined amplitude for sampling by the ADC.

15. The system of claim 13, further comprising a phase delay and amplitude computation module for determining a phase delay and amplitude of the extracted signal and the phase delay and amplitude of first digitized signal and generating an adjustment to the extracted signal based on the phase delay and amplitude of the first digitized signal.

16. The system of claim 13, wherein the signal phase and amplitude adjustment module adjusts the phase delay of the extracted signal to generate the adjusted extracted signal that is 180 degrees out of phase with the first digitized signal.

17. The system of claim 13, wherein the neuromorphic signal processor comprises:

a delay embedding module, the delay embedding module receives the second digitized signal and generates a delay embedded mixture signal based on the second digitized signal;

a reservoir, the reservoir being configured to linearly map the delay embedded mixture signal into the reservoir to create a multi-dimensional state-space representation of the mixture signal by combining the delay embedded mixture signal with a plurality of reservoir states;

an output layer, the output layer being configured to generate a set of pre-filtered signals by linearly mapping the state-space representation to one or more output nodes in the output layer; and

a bank of adaptable filters, the bank of filters being configured to generate the separate source signals that collectively formed the mixture signal by processing the pre-filtered signals through the bank of adaptable filters, at least one of the separate source signals being identified as the extracted signal.

18. The system of claim 17, wherein the reservoir comprises a plurality of processing nodes and the output layer comprise a set of output nodes, each output node receives a weighted output from each processing node as an input, each output node sums these values together to produce its output weight, the output weight of each output node amplifies a subset of the source signals while suppressing others, the extracted signal being identified from the separate source signals.

19. The system of claim 13, further comprising a device for examining a spectrum of the input examination signal.

20. A computer program product for removing an extracted radio frequency (RF) signal to examine a spectrum of at least one other RF signal, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, wherein the computer readable storage medium is not a transitory medium per se, the program instructions being executable by a device to cause the device to perform a method comprising:

receiving a mixture signal by an analog-to-digital converter (ADC), the mixture signal comprising a plurality of separate source signals from different signal sources;

digitizing the mixture signal by the ADC and generating a first digitized signal and a second digitized signal, wherein the first digitized signal is the same as the second digitized signal;

delaying the first digitized signal by a predetermined time delay;

processing the second digitized signal in a neuromorphic signal processor to extract an extracted signal from the second digitized signal, wherein the predetermined time delay corresponds to a delay embedding in the neuromorphic signal processor;

adjusting a phase delay and amplitude of the extracted signal based on a phase delay and amplitude of the first digitized signal; and

cancelling an adjusted extracted signal from the first digitized signal to provide an input examination signal.