Transmitter linearized using cartesian-processed look-up table and method therefor

A transmitter includes a nonlinear predistorter having two instances of an inverting transform that may be implemented in a look-up table and that implements a transform which is the inverse of an average terms component of a nonlinear transform model for an amplifier. The look-up table may be updated using a continuous process control loop that avoids Cartesian to polar coordinate conversions. One of the two instances of the inverting transform is cascaded with a non-inversing transform within a residual cancellation section of the predistorter. The non-inversing transform implements a transform which is an estimate of a deviation terms component of the nonlinear transform model. The residual cancellation section produces a weak signal that replaces an unwanted residual term in an amplified communication signal with a much weaker residual term.