Interference cancellation methods and apparatus

• US 10,321,357 B1
• Filed: 07/23/2018
• Issued: 06/11/2019
• Est. Priority Date: 07/16/2016
• Status: Active Grant

• Current Assignee: GenXComm Inc.
• Original Assignee: GenXComm Inc.
• Inventors: Jain, Hardik, Lin, Che-Chun
• Primary Examiner(s): Bello, Agustin
• Application Number:
  US16/042,899
• Time in Patent Office: 323 Days
• Field of Search: 398 39, 398115-117
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04B 10/2507 for the reduction or elimination of distortion or dispersion
• CPC Class Codes: H04B 10/25752 Optical arrangements for wireless networks
• CPC Class Codes: H04B 2210/006 Devices for generating or processing an RF signal by optical means
• CPC Class Codes: H04L 25/03006 Arrangements for removing intersymbol interference
• CPC Class Codes: H04W 28/04 Error control

Abstract

Methods and apparatus for reducing and/or canceling signal interference between receiver and transmitter components of a wireless communications device are described. The methods and apparatus are well suited for use in a wide range of devices including user equipment devices such as cell phones as well as in network equipment such a base stations. Opto-mechanical devices are used in some embodiments as part of an apparatus which performs interference cancelation on RF (Radio Frequency) signals.

Claims

1. Apparatus configured to cancel digital signal interference between a digital transmit element and a receiver element, said apparatus comprising:

a digital interference cancelation element for generating a filter delay control signal, the digital interference cancelation element producing a baseband interference cancelation signal;

a combining element in an RF receiver signal path; and

an RF cancelation filter positioned between an RF transmit signal path and the combining element in the RF receiver signal path, the combining element receiving at a first input an RF frequency signal generated by the RF cancelation filter from a signal received from the RF transmit signal path, said RF frequency signal delayed in accordance with delay control information received from the digital interference cancelation element.

2. The apparatus of claim 1, wherein the combining element subtracts the RF frequency signal generated by the RF cancelation filter from a received signal supplied to a received signal input of the combining element.

3. The apparatus of claim 1,

wherein the combining element is an adder which adds the RF frequency signal generated by the RF cancelation filter from a received signal supplied to a received signal input of the combining element;

and

wherein the cancelation signal is an inverse of an estimate of a received interference signal.

4. The apparatus of claim 1, wherein said RF cancelation filter includes:

a first interference signal component generation chain including a first opto-mechanical modulator and a first configurable delay element, and a first optical to electrical (O/E) converter for generating an electrical version of the first interference signal component.

5. The apparatus of claim 4, wherein said RF cancelation filter further includes:

a second interference signal component generation chain including a second opto-mechanical modulator and a second configurable delay element, and a second optical to electrical (O/E) converter for generating an electrical version of the first interference signal component.

6. The apparatus of claim 5, further comprising:

an interference signal component combiner for combining the electrical versions of said first and second interference signal components to generate a composite RF interference signal, said composited RF interference signal being the RF frequency signal generated by the RF cancelation filter.

7. The apparatus of claim 6, further comprising:

a first switch between the first O/E converter and a first input of said interference signal component combiner,

a second switch between the second O/E converter and a second input of said interference signal component combiner; and

a controller for receiving the filter delay control signal from the digital interference cancelation element and controlling said first and second switches based on the amount of delay to be applied to the received RF signal as part of generation of the RF frequency signal to be subtracted from the received RF signal.

8. The apparatus of claim 6, wherein the first opto-mechanical module includes the following:

piezo-structure or opto-mechanical structure, to perform an RF to acoustical signal conversion operation.

9. The apparatus of claim 8, wherein the first interference signal component generation chain further includes a first waveguide, said acoustic signal influencing a first optical carrier passing through said first waveguide prior to reaching said first O/E converter.

10. The apparatus of claim 9, wherein said first waveguide varies in width.

11. The apparatus of claim 6, wherein the first opto-mechanical module includes a plurality of piezo-structures or opto-mechanical structures to perform an RF to acoustical signal conversion operation, at least one of the opto-mechanical structures influencing an optical signal passing through a first waveguide influencing the signal delay introduced by said first interference signal component generation chain when generating the first interference signal component.

12. The apparatus of claim 9, wherein the first interference signal component generation chain further includes:

a heater positioned along the first waveguide, said heater controlled to be in an on-state influencing a signal delay introduced by the use of said first waveguide.

23. A semiconductor comprising the apparatus of claim 1.

24. An electronic system comprising the apparatus of claim 1.

13. A method of performing radio frequency (RF) interference cancelation comprising:

supplying an RF signal to a transducer to produce a signal which carries said RF signal;

receiving at a control input a control signal;

using the control signal to control phonon-photon transduction of the signal which carries the RF signal on to an optical signal being communicated through a waveguide;

performing an optical to electrical conversion on an optical signal that exits the waveguide to produce an electrical interference cancelation signal; and

using said electrical interference cancelation signal in an interference cancelation operation performed on a received RF signal which includes interference.

14. The method of claim 13, wherein using said electrical interference signal in an interference cancelation operation includes:

combining the received RF signal with the electrical interference cancelation signal.

15. The method of claim 14, wherein said using the control signal to control phonon-photon transduction of the signal which carries the RF signal on to an optical signal being communicated through a waveguide includes:

modifying at least one of the following;

i) a property of a medium through which the signal which carries the RF signal travels to reach the waveguide;

ii) a property of the waveguide, and

iii) a directivity of the transducer.

16. The method of claim 14, wherein said using the control signal to control phonon-photon transduction of the signal which carries the RF signal on to an optical signal being communicated through a waveguide includes:

modifying at least one of the following;

a property of a medium through which the signal travels to reach the waveguide, and

a property of the waveguide,

said modifying including heating at least one portion of the medium or waveguide.

17. The method of claim 15, wherein said modifying alters a gain of said phonon-photon transduction.

18. The method of claim 16, wherein said modifying alters a location of said phonon-photon transduction thereby controlling an amount of signal delay.

19. The method of claim 14, wherein said using the control signal to control phonon-photon transduction of the signal which carries the RF signal on to an optical signal includes:

controlling which of a plurality of differently oriented transducers has a largest phonon-photon transduction gain of the signal which carries the RF signal on to an optical signal.

27. The method of claim 13, further comprising:

in said supplying, said signal which carries the RF signal comprising an acoustic signal.

28. The method of claim 27, further comprising:

in said supplying, providing the RF signal to a transducer that oscillates to produce the acoustic signal which carries the RF signal.

29. A method of operating an electronic system, said method comprising:

performing the method of claim 13.

20. A radio frequency (RF) interference cancelation apparatus:

a transducer that oscillates to produce an acoustic signal which carries an RF signal supplied as an input to said transducer;

a control input that receives a control signal used to control phonon-photon transduction of the acoustic signal which carries the RF signal on to an optical signal being communicated through a waveguide;

an optical to electrical converter that converts an optical signal that exits the waveguide to an electrical interference cancelation signal; and

a combiner for combining said electrical interference cancelation signal with a received RF signal which includes interference.

21. The radio frequency interference cancelation apparatus of claim 20, further comprising:

at least one heating element positioned along a portion of said waveguide or transducer which is controlled by said control signal.

22. The radio frequency interference cancelation apparatus of claim 21, wherein the first transducer is one of a plurality of differently oriented transducers.

25. A semiconductor comprising the radio frequency interference cancelation apparatus of claim 20.

26. An electronic system comprising the radio frequency interference cancelation apparatus of claim 20.