Patent ID: 8588353

Claim:
An apparatus comprising: baseband circuitry; a digital predistortion (DPD) module that is coupled to receive a transmit signal from the baseband circuitry; a transmit interface that is coupled to the DPD module to receive a predistorted transmit signal; a feedback interface that is adapted to receive in-phase (I) and quadrature (Q) feedback signals; an IQ correction filter having: a signal band detector that is coupled to a receive interface to receive a reference signal from the baseband circuitry; an IQ estimator that is coupled to the receive interface to receive the I and Q feedback signals and that is coupled to the signal band detector to receive a mask, wherein the mask corresponds to the band of the I and Q feedback signals; and an IQ compensator is coupled to the receive interface to receive the I and Q feedback signals and that is coupled to the IQ estimator to receive a correction, wherein the IQ compensator applies the correction to the I and Q feedback signals so as to provide corrected I and Q feedback signals to the DPD module, wherein the DPD module is implement in software embodied on a processor and memory; wherein the IQ correction filter is implemented in software embodied on the processor and memory; and wherein the correction is a correction function that is the product of a pseudoinverse of a sub-matrix for the band of the I and Q feedback signals of a discrete Fourier transform matrix and a subset of a frequency response indexed by the mask.