Method and apparatus for digital post-distortion compensation of signal non-linearities
AssigneePMC-Sierra US, Inc.
InventorsWilliam D. Warner, Clarence K. L. Tam
Life of this patent
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Abstract
A method and apparatus to digitally remove in-band non-linear signal distortion caused by a radio frequency (RF)/intermediate frequency (IF) receiver circuit that has non-linearities, which are further affected by low-IF ADC sample aliasing.
Claims28
A method to compensate for non-linearity distortion in a radio frequency (RF) receiver, the RF receiver outputting a digitized RF signal, the method comprising:
- converting the digitized RF signal into a complex baseband signal;
- rotating the complex baseband signal to obtain a rotated complex baseband signal at 0 Hz;
- calculating, as a function of the rotated complex baseband signal, compensation distortion components for a set of pre-determined distortion orders, the compensation distortion components including at least one of harmonic distortion components and intermodulation distortion components;
- and
- subtracting the compensation distortion components from the rotated complex baseband signal to obtain a compensated complex baseband signal.
A method of calculating compensation distortion components factors, the compensation distortion components to compensate for non-linearity distortion in a radio frequency (RF) receiver, the method comprising:
- receiving, from the RF receiver, a digitized RF reference signal;
- converting the digitized RF reference signal into a complex baseband signal;
- rotating the complex baseband signal to obtain a rotated complex baseband signal at 0 Hz;
- calculating, as a function of the rotated complex baseband signal, compensation distortion components for a set of pre-determined distortion orders;
- calculating a frequency content function of the a rotated complex baseband signal at 0 Hz;
- calculating a frequency content function of the each of the compensation distortion component;
- and
- for each particular compensation distortion component, dividing the frequency content function of the a rotated complex baseband signal at 0 Hz by the frequency content function of the particular distortion component to obtain the compensation distortion components factor of the particular distortion component.
A non-transitory, tangible computer-readable medium having recorded thereon instructions to be carried out by a processor to perform a method to compensate for non-linearity distortion in a radio frequency (RF) receiver, the RF receiver outputting a digitized RF signal, the method comprising:
- converting the digitized RF signal into a complex baseband signal;
- rotating the complex baseband signal to obtain a rotated complex baseband signal at 0 Hz;
- calculating, as a function of the rotated complex baseband signal, compensation distortion components for a set of pre-determined distortion orders, the compensation distortion components including at least one of harmonic distortion components and intermodulation distortion components;
- and
- subtracting the compensation distortion components from the rotated complex baseband signal to obtain a compensated complex baseband signal.
A non-transitory, tangible computer-readable medium having recorded thereon instructions to be carried out by a processor to perform a method of calculating compensation distortion components factors, the compensation distortion components to compensate for non-linearity distortion in a radio frequency (RF) receiver, the method comprising:
- receiving, from the RF receiver, a digitized RF reference signal;
- converting the digitized RF reference signal into a complex baseband signal;
- rotating the complex baseband signal to obtain a rotated complex baseband signal at 0 Hz;
- calculating, as a function of the rotated complex baseband signal, compensation distortion components for a set of pre-determined distortion orders;
- calculating a frequency content function of the a rotated complex baseband signal at 0 Hz;
- calculating a frequency content function of the each of the compensation distortion component;
- and
- for each particular compensation distortion component, dividing the frequency content function of the a rotated complex baseband signal at 0 Hz by the frequency content function of the particular distortion component to obtain the compensation distortion components factor of the particular distortion component.
Dependencies are inferred from the claim text.