Methods and Devices for Self-Interference Cancelation

Abstract

A communication circuit arrangement includes a signal path circuit to estimate, using a first kernel dimension filter and a first delay tap dimension filter, a first interference signal produced by a first amplifier. The signal path circuit further estimates, using a second kernel dimension filter and a second delay tap dimension filter, a second interference signal produced by a second amplifier. A cancellation circuit of the communication circuit arrangement may subtract a combination of the first interference signal and the second interference signal from a received signal to obtain a filtered signal, and one or more filter adaptation circuits may alternate between a kernel update phase and a delay update phase to update the first kernel dimension filter and the second kernel dimension filter during the kernel update phase, and update the first delay tap dimension filter and the second delay tap dimension filter during the delay update phase.

1 . A communication circuit comprising:
 a signal path circuit configured to
 estimate, using a first kernel dimension filter and a first delay tap dimension filter, a first interference signal from a first amplifier, and 
 estimate, using a second kernel dimension filter and a second delay tap dimension filter, a second interference signal from a second amplifier; and 
   a cancellation circuit configured to subtract a combination of the estimated first interference signal and the estimated second interference signal from a received signal to obtain a filtered received signal, wherein the combination of the estimated first interference signal and the estimated second interference signal is representative of signal interference caused by signal leakage into a receive path of the received signal.   
     
     
         2 . The communication circuit of  claim 1 , further comprising:
 one or more receive chains;   a first transmit chain comprising the first amplifier;   a second transmit chain comprising the second amplifier; and   one or more antennas coupled to the one or more receive chains and the first transmit chain.   
     
     
         3 . The communication circuit of  claim 1 , wherein the signal path circuit is further configured to:
 obtain the estimated first interference signal by applying a first filter circuit that comprises the first kernel dimension filter and the first delay tap dimension filter to an input signal of the first amplifier; and   obtain the estimated second interference signal by applying a second filter circuit that comprises the second kernel dimension filter and the second delay tap dimension filter to an input signal of the second amplifier.   
     
     
         4 . The communication circuit of  claim 3 , further comprising:
 a first kernel generation circuit configured to process the input signal of the first amplifier to derive a corresponding first plurality of kernel signals, each of the first plurality of kernel signals approximating a non-linear component of a leakage path of the first amplifier, and   a second kernel generation circuit configured to process the input signal of the second amplifier to derive a corresponding second plurality of kernel signals, each of the second plurality of kernel signals approximating a non-linear component of a leakage path of the second amplifier,   wherein applying the first filter circuit to the input signal of the first amplifier comprises applying the first kernel dimension filter to the first plurality of kernel signals, and   wherein applying the second filter circuit to the input signal of the second amplifier comprises applying the second kernel dimension filter to the second plurality of kernel signals.   
     
     
         5 . The communication circuit of  claim 1 , further comprising:
 one or more filter adaptation circuits configured to:
 alternate between a kernel update phase and a delay update phase, 
 update the first kernel dimension filter and the second kernel dimension filter during the kernel update phase, and 
 update the first delay tap dimension filter and the second delay tap dimension filter during the delay update phase. 
   
     
     
         6 . The communication circuit of  claim 2 , wherein:
 the first amplifier is configured to amplify a first input signal to form a first amplified signal;   the second amplifier is configured to amplify a second input signal to form a second amplified signal;   the one or more antennas are configured to transmit the first amplified signal and the second amplified signal;   the estimated first interference signal is based on the first input signal; and   the estimated second interference signal is based on the second input signal.   
     
     
         7 . The communication circuit of  claim 2 , wherein:
 the receive path comprises a first receive chain of the one or more receive chains;   the first receive chain is configured to receive the received signal via the one or more antennas; and   the combination of the estimated first interference signal and the estimated second interference signal is an approximation of signal leakage from the first transmit chain and the second transmit chain into the first receive chain.   
     
     
         8 . The communication circuit of  claim 1 , wherein the signal path circuit comprises:
 a combiner configured to combine the estimated first interference signal with the estimated second interference signal to obtain the combination of the estimated first interference signal and the estimated second interference signal.   
     
     
         9 . A wireless communication device comprising:
 one or more receive chains;   a first transmit chain comprising a first amplifier;   a second transmit chain comprising a second amplifier;   one or more antennas coupled to the one or more receive chains and the first transmit chain; and   cancellation circuitry configured to
 estimate, using a first kernel dimension filter and a first delay tap dimension filter, a first interference signal from a first amplifier, 
 estimate, using a second kernel dimension filter and a second delay tap dimension filter, a second interference signal from a second amplifier, and 
 subtract a combination of the estimated first interference signal and the estimated second interference signal from a received signal to obtain a filtered received signal, wherein the combination of the estimated first interference signal and the estimated second interference signal is representative of signal interference associated with the first amplifier and the second amplifier and affecting the received signal. 
   
     
     
         10 . The wireless communication device of  claim 9 , wherein the cancellation circuitry comprises one or more filter adaptation circuits configured to:
 alternate between a kernel update phase and a delay update phase;   update the first kernel dimension filter and the second kernel dimension filter during the kernel update phase; and   update the first delay tap dimension filter and the second delay tap dimension filter during the delay update phase.   
     
     
         11 . The wireless communication device of  claim 9 , wherein the cancellation circuitry is further configured to:
 obtain the estimated first interference signal by applying a first filter circuit that comprises the first kernel dimension filter and the first delay tap dimension filter to an input signal of the first amplifier; and   obtain the estimated second interference signal by applying a second filter circuit that comprises the second kernel dimension filter and the second delay tap dimension filter to an input signal of the second amplifier.   
     
     
         12 . The wireless communication device of  claim 11 , wherein the cancellation circuitry comprises:
 a first kernel generation circuit configured to process the input signal of the first amplifier to derive a corresponding first plurality of kernel signals, each of the first plurality of kernel signals approximating a non-linear component of a leakage path of the first amplifier; and   a second kernel generation circuit configured to process the input signal of the second amplifier to derive a corresponding second plurality of kernel signals, each of the second plurality of kernel signals approximating a non-linear component of a leakage path of the second amplifier;   wherein applying the first filter circuit to the input signal of the first amplifier comprises applying the first kernel dimension filter to the first plurality of kernel signals, and   wherein applying the second filter circuit to the input signal of the second amplifier comprises applying the second kernel dimension filter to the second plurality of kernel signals.   
     
     
         13 . The wireless communication device of  claim 9 , wherein:
 the first amplifier is configured to amplify a first input signal to form a first amplified signal;   the second amplifier is configured to amplify a second input signal to form a second amplified signal;   the one or more antennas are configured to transmit the first amplified signal and the second amplified signal;   the estimated first interference signal is based on the first input signal; and   the estimated second interference signal is based on the second input signal.   
     
     
         14 . The wireless communication device of  claim 9 , wherein:
 wherein a first receive chain of the one or more receive chains is configured to receive the received signal via the one or more antennas; and   the combination of the estimated first interference signal and the estimated second interference signal is an approximation of signal leakage from the first transmit chain and the second transmit chain into the first receive chain.   
     
     
         15 . A method of performing interference cancellation, the method comprising:
 estimating, using a first kernel dimension filter and a first delay tap dimension filter, a first interference signal from a first amplifier;   estimating, using a second kernel dimension filter and a second delay tap dimension filter, a second interference signal from a second amplifier; and   subtracting a combination of the first interference signal and the second interference signal from a received signal to obtain a filtered received signal, wherein the combination of the first interference signal and the second interference signal is representative of signal interference affecting the received signal.   
     
     
         16 . The method of  claim 15 , further comprising:
 updating the first kernel dimension filter and the second kernel dimension filter during a kernel update phase;   updating the first delay tap dimension filter and the second delay tap dimension filter during a delay update phase; and   alternating between the kernel update phase and the delay update phase.   
     
     
         17 . The method of  claim 15 , wherein:
 estimating the first interference signal comprises applying a first filter circuit that comprises the first kernel dimension filter and the first delay tap dimension filter to an input signal of the first amplifier; and   estimating the second interference signal comprises applying a second filter circuit that comprises the second kernel dimension filter and the second delay tap dimension filter to an input signal of the second amplifier.   
     
     
         18 . The method of  claim 17 , further comprising:
 deriving a first plurality of kernel signals by processing the input signal of the first amplifier, each of the first plurality of kernel signals approximating a non-linear component of a leakage path of the first amplifier; and   deriving a second plurality of kernel signals by processing the input signal of the second amplifier, each of the second plurality of kernel signals approximating a non-linear component of a leakage path of the second amplifier;   wherein applying the first filter circuit to the input signal of the first amplifier comprises applying the first kernel dimension filter to the first plurality of kernel signals, and   wherein applying the second filter circuit to the input signal of the second amplifier comprises applying the second kernel dimension filter to the second plurality of kernel signals.   
     
     
         19 . The method of  claim 15 , further comprising:
 generating a first amplified signal by amplifying a first input signal via the first amplifier;   generating a second amplified signal by amplify a second input signal via the second amplifier;   transmitting the first amplified signal and the second amplified signal via one or more antennas;   wherein the estimated first interference signal is based on the first input signal; and   wherein the estimated second interference signal is based on the second input signal.   
     
     
         20 . The method of  claim 15 , wherein:
 the first amplifier is comprised in a first transmit path;   the second amplifier is comprised in a second transmit path;   the received signal is received in a receive chain; and   the combination of the estimated first interference signal and the estimated second interference signal is an approximation of signal leakage from the first transmit chain and the second transmit chain into the receive chain.