Patent ID: 7551686

Claim:
A method of pre-distorting a transmit signal to compensate for AM to AM and AM to PM distortion of a power amplifier in a wireless transmitter comprising: selecting a select set of coefficients from a plurality of sets of coefficients defining a corresponding plurality of polynomials based on a power control signal and an amplitude component of a polar transmit signal, the plurality of sets of coefficients comprising a set of coefficients describing an amplitude compensation signal that essentially cancels an AM to AM distortion of power amplifier circuitry for each of at least two subsets of an input value range of the power amplifier circuitry for each of at least two power levels of the power amplifier circuitry; and distorting the amplitude component of the polar transmit signal based on the polynomial defined by the select set of coefficients, thereby providing a pre-distorted amplitude component of a pre-distorted transmit signal.