Interference cancellation methods and apparatus
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.
1. An apparatus comprising:
a digital interference cancelation element configured to generate delay control information comprising a filter delay control signal;
an RF cancelation filter configured to generate an RF frequency signal, the RF cancellation filter comprising a first interference signal component generation chain comprising a first optomechanical modulator and a first configurable delay element, and a first optical to electrical converter configured to generate a first electrical version of an interference signal component; and
a combining element configured to combine the RF frequency signal delayed in accordance with the delay control information.
2. The apparatus of claim 1 , wherein the delay control information further comprises an interference cancelation signal.
3. The apparatus of claim 1 , wherein the combining element is configured to subtract the interference cancellation signal from a received signal.
4. The apparatus of claim 1 , wherein the combining element is configured to add the interference cancellation signal to a received signal.
5. The apparatus of claim 1 , wherein the RF cancelation filter further comprises:
a second interference signal component generation chain comprising a second optomechanical modulator and a second configurable delay element, and a second optical to electrical converter configured to generate a second electrical version of the interference signal component.
6. The apparatus of claim 5 , further comprising:
an interference component signal combiner configured to combine the first and second electrical versions of the interference signal component to generate a composite RF interference signal.
7. The apparatus of claim 6 , further comprising:
a first switch between the first optical to electrical converter and the interference signal component combiner;
a second switch between the second optical to electrical converter and the interference signal component combiner; and
a controller configured to receive the delay control information and control said first and second switches based on the amount filter delay control signal.
8. The apparatus of claim 1 , wherein the first optomechanical modulator comprises a piezo-structure configured to perform an RF to acoustic signal conversion operation.
9. The apparatus of claim 1 , wherein the first optomechanical modulator comprises an opto-structure configured to perform an RF to acoustic signal conversion operation.
10. The apparatus of claim 5 , wherein the second optomechanical modulator comprises a piezo-structure configured to perform an RF to acoustic signal conversion operation.
11. The apparatus of claim 5 , wherein the second optomechanical modulator comprises an opto-structure configured to perform an RF to acoustic signal conversion operation.
12. The apparatus of claim 1 , the first interference signal component generation chain further comprising:
a first waveguide, wherein said acoustic signal influencing a first optical carrier passing through the first waveguide prior to reaching the first optical to electrical converter.
13. The apparatus of claim 5 , the second interference signal component generation chain further comprising:
a second waveguide, wherein said acoustic signal influencing a second optical carrier passing through the second waveguide prior to reaching the second optical to electrical converter.