Digital self-interference residual cancellation

• US 9,647,705 B2
• Filed: 12/29/2015
• Issued: 05/09/2017
• Est. Priority Date: 07/16/2015
• Status: Active Grant

• Current Assignee: LGS Innovations LLC (CACI International Incorporated)
• Original Assignee: LGS Innovations LLC (CACI International Incorporated)
• Inventors: Pack, Riley Nelson, Brannon, Alan Scott, Baker, Benjamin Joseph
• Primary Examiner(s): GONZALES, APRIL GUZMAN
• Application Number:
  US14/982,428
• Publication Number:
  US 20170019190A1
• Time in Patent Office: 497 Days
• Field of Search: 455 78
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H04B 1/0003 Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain digital baseband systems H04L25/00; digital modulation/demodulation H04L27/00; CDMA H04B1/707; TDMA H04B7/2643; image transmission H04N5/00
• CPC Class Codes: H04B 1/0042 Digital filtering H04B1/0035 takes precedence; digital filters per se H03H17/00
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04B 1/10 Means associated with receiver for limiting or suppressing noise or interference
• CPC Class Codes: H04B 1/1036 with automatic suppression of narrow band noise or interference, e.g. by using tuneable notch filters H04B1/123 takes precedence; filter circuits H03H
• CPC Class Codes: H04B 1/401 for selecting or indicating operating mode
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04B 1/715 Interference-related aspects
• CPC Class Codes: H04B 15/00 Suppression or limitation of noise or interference by means associated with receiver H04B1/10
• CPC Class Codes: H04B 15/02 Reducing interference from electric apparatus by means located at or near the interfering apparatus
• CPC Class Codes: H04B 2001/0408 with power amplifiers
• CPC Class Codes: H04L 25/0212 of impulse response
• CPC Class Codes: H04L 25/025 using least-mean-square [LMS] method
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex
• CPC Class Codes: H04L 5/1461 Suppression of signals in the return path, i.e. bidirectional control circuits

Abstract

The present application a digital self-interference residual cancellation method that adjusts a magnitude of a sampled transmit signal based on compared magnitude and phases associated with tones. The digital self-interference residual cancellation method may follow an analog carrier cancellation stage where the digital self-interference residual cancellation is based on a determination of the channel circuit response used to control an infinite impulse response filter which can compensate using both poles and zeroes.

Claims

1. A digital self-interference residual cancellation method, the method comprising:

determining a first magnitude and a first phase of a tone in a receive signal;

determining a second magnitude and a second phase of the tone in a sampled transmit signal;

comparing the first magnitude with the second magnitude;

comparing the first phase with the second phase;

adjusting a magnitude of the sampled transmit signal based on the comparing of the first magnitude with the second magnitude; and

adjusting a phase of the sampled transmit signal based on the comparing of the first phase with the second phase.

2. The digital self-interference residual cancellation method of claim 1, wherein the determining of the first magnitude and the first phase is based on a Fast Fourier transform of the tone.

3. The digital self-interference residual cancellation method of claim 1, wherein the adjusting of the phase of the sampled transmit signal is based on the use of a phase loop filter.

4. The digital self-interference residual cancellation method of claim 1, wherein the adjusting of the magnitude of the sampled transmit signal is based on the use of a gain loop filter.

5. The digital self-interference residual cancellation method of claim 1, wherein the sampled transmit signal is an output of an infinite impulse response filter.

6. The digital self-interference residual cancellation method of claim 1, further comprising calibrating a coefficient of the infinite impulse response filter.

7. The digital self-interference residual cancellation method of claim 1, wherein the calibrating of a coefficient of the infinite impulse response filter is based on the use of a controller.

8. The digital self-interference residual cancellation method of claim 1, wherein the sampled transmit signal is phase shifted to remove interference from the receive signal.

9. A device comprising:

a processor; and

a memory coupled with the processor, the memory comprising executable instructions that when executed by the processor cause the processor to effectuate operations comprising;

determining a first magnitude and a first phase of a tone in a receive signal;

determining a second magnitude and a second phase of the tone in a sampled transmit signal;

comparing the first magnitude with the second magnitude;

comparing the first phase with the second phase;

adjusting a magnitude of the sampled transmit signal based on the comparing of the first magnitude with the second magnitude; and

adjusting a phase of the sampled transmit signal based on the comparing of the first phase with the second phase.

10. The device of claim 9, wherein the determining of the first magnitude and the first phase is based on a Fast Fourier transform of the tone.

11. The device of claim 9, wherein the adjusting of the phase of the sampled transmit signal is based on the use of a phase loop filter.

12. The device of claim 9, wherein the adjusting of the magnitude of the sampled transmit signal is based on the use of a gain loop filter.

13. The device of claim 9, wherein the sampled transmit signal is an output of an infinite impulse response filter.

14. The device of claim 9, the operations further comprising calibrating a coefficient of the infinite impulse response filter.

15. The device of claim 9, the operations further comprising calibrating of a coefficient of the infinite impulse response filter based on the use of a controller.

16. The device of claim 9, wherein the sampled transmit signal is phase shifted to remove interference from the receive signal.

17. A non-transitory computer readable storage medium comprising computer executable instructions that when executed by a computing device cause said computing device to effectuate operations comprising:

determining a first magnitude and a first phase of a tone in a receive signal;

determining a second magnitude and a second phase of the tone in a sampled transmit signal;

comparing the first magnitude with the second magnitude;

comparing the first phase with the second phase;

adjusting a magnitude of the sampled transmit signal based on the comparing of the first magnitude with the second magnitude; and

adjusting a phase of the sampled transmit signal based on the comparing of the first phase with the second phase.

18. The non-transitory computer readable storage medium of claim 17, wherein the adjusting of the phase of the sampled transmit signal is based on the use of a phase loop filter.

19. The non-transitory computer readable storage medium of claim 17, wherein the adjusting of the magnitude of the sampled transmit signal is based on the use of a gain loop filter.

20. The non-transitory computer readable storage medium of claim 17, wherein the sampled transmit signal is an output of an infinite impulse response filter.