Method and apparatus for adaptive non-linear self-jamming interference cancellation
Certain embodiments of the disclosure propose a method for cancelling co-channel interference (self-jamming) generated by nonlinearities in the radio-frequency (RF) front-end devices. The proposed method utilizes an adaptive non-linear filter to generate a distorted version of the transmitted signal. The self-jamming interference may be mitigated utilizing the distorted signal through adaptive cancellation.
1. A method, comprising:
generating a signal to be transmitted on a first frequency band;
constructing a distorted version of the generated signal by applying an adaptive non-linear filter to a baseband portion of the generated signal, wherein coefficients of the adaptive non-linear filter are generated by minimizing a MSE (Minimum Square Error) cost function;
transmitting the generated signal on the first frequency band;
receiving a signal on a second frequency band, the received signal being corrupted by self-jamming interference, wherein the self-jamming interference is caused by any type of non-linearities generated by transmit and receive chains; and
subtracting the distorted version of the generated signal from the received signal to remove the self-jamming interference.
2. The method of claim 1 , further comprising applying frequency shifting at an output of the adaptive non-linear filter for self-jamming interference which is not DC centered.
3. The method of claim 1 , wherein the cost function is minimized by utilizing at least one of a least mean square (LMS) or a recursive least squares (RLS) algorithm.
4. The method of claim 3 , wherein an error signal is generated by subtracting output of the adaptive non-linear filter from the received signal.
5. The method of claim 4 , where the error signal is generated by subtracting output of the adaptive non-linear filter, after frequency shifting and low-pass filtering, from the received signal.
6. The method of claim 1 , wherein the self-jamming interference comprises a p-order inter-modulation distortion where p>1.
7. The method of claim 6 , wherein even-order non-linear filter operators are applied to the baseband portion of the generated signal.
8. The method of claim 6 , wherein odd-order non-linear filter operators are applied to the baseband portion of the generated signal.
9. The method of claim 6 , wherein even-order and odd-order non-linear filter operators are applied to the baseband portion of the generated signal.
10. The method of claim 6 , wherein memory related effects are taken into account by augmenting the adaptive non-linear filter with digital memory elements and applying the adaptive non-linear filter and the digital memory elements to the baseband portion of the generated signal.
11. The method of claim 1 , wherein the transmitted and received signals are wireless signals.
12. The method of claim 1 , wherein the transmitted and received signals are wired signals.
13. The method of claim 1 , wherein multiple signals transmitted simultaneously in a multi-mode or multi-carrier transceiver may result in reciprocal intermodulation products.
14. An apparatus, comprising:
means for generating a signal to be transmitted on a first frequency band;
means for constructing a distorted version of the generated signal by applying an adaptive non-linear filter to a baseband portion of the generated signal, wherein coefficients of the adaptive non-linear filter are generated by minimizing a MSE (Minimum Square Error) cost function;
means for transmitting the generated signal on the first frequency band;
means for receiving a signal on a second frequency band, the received signal being corrupted by self-jamming interference, wherein the self-jamming interference is caused by any type of non-linearities generated by transmit and receive chains; and
means for subtracting the additional distorted version of the generated signal from the received signal to remove the self-jamming interference.
15. The apparatus of claim 14 , further comprising means for applying frequency shifting at an output of the adaptive non-linear filter for self-jamming interference which is not DC centered.
16. The apparatus of claim 14 , wherein the cost function is minimized by utilizing at least one of a least mean square (LMS) or a recursive least squares (RLS) algorithm.
17. The apparatus of claim 16 , wherein an error signal is generated by subtracting output of the adaptive non-linear filter from the received signal.
18. The apparatus of claim 17 , where the error signal is generated by subtracting output of the adaptive non-linear filter, after frequency shifting and low-pass filtering, from the received signal.
19. The apparatus of claim 14 , wherein the self-jamming interference comprises a p-order inter-modulation distortion where p>1.
20. The apparatus of claim 19 , wherein even-order non-linear filter operators are applied to the baseband portion of the generated signal.
21. The apparatus of claim 19 , wherein odd-order non-linear filter operators are applied to the baseband portion of the generated signal.
22. The apparatus of claim 19 , wherein even-order and odd-order non-linear filter operators are applied to the baseband portion of the generated signal.
23. The apparatus of claim 19 , wherein memory related effects are taken into account by augmenting the adaptive non-linear filter with digital memory elements and applying adaptive non-linear filter and the digital memory elements to the baseband portion of the generated signal.
24. The apparatus of claim 14 , wherein the transmitted and received signals are wireless signals.
25. The apparatus of claim 14 , wherein the transmitted and received signals are wired signals.
26. The apparatus of claim 14 , wherein multiple signals transmitted simultaneously in a multi-mode or multi-carrier transceiver may result in reciprocal intermodulation products.
27. An apparatus, comprising:
at least one processor configured to:
generate a signal to be transmitted on a first frequency band, construct a distorted version of the generated signal by applying an adaptive non-linear filter to a baseband portion of the generated signal, wherein coefficients of the adaptive non-linear filter are generated by minimizing a MSE (Minimum Square Error) cost function, transmit the generated signal on the first frequency band, receive a signal on a second frequency band, the received signal being corrupted by self-jamming interference, wherein the self-jamming interference is caused by any type of non-linearities generated by transmit and receive chains, and subtract the additional distorted version of the generated signal from the received signal to remove the self-jamming interference; and
a memory coupled with the at least one processor.
28. A computer-program product comprising a non-transitory computer-readable medium having instructions stored thereon, the instructions executable by a processor for:
generating a signal to be transmitted on a first frequency band;
constructing a distorted version of the generated signal by applying an adaptive non-linear filter to a baseband portion of the generated signal, wherein coefficients of the adaptive non-linear filter are generated by minimizing a MSE (Minimum Square Error) cost function;
transmitting the generated signal on the first frequency band;
receiving a signal on a second frequency band, the received signal being corrupted by self-jamming interference, wherein the self-jamming interference is caused by any type of non-linearities generated by transmit and receive chains; and
subtracting the additional distorted version of the generated signal from the received signal to remove the self-jamming interference.