In an amplifier system that linearizes an amplifier by pre-distorting the input signal prior to amplification, a baseband pre-distortion processor processes the input signal in a digital baseband domain to generate one or more pre-distortion parameters based on the power of the digital baseband input signal. The digital baseband signal is up-converted and D/A-converted into a non-baseband (e.g., IF or RF) signal which is then pre-distorted, e.g., using a phase/gain adjuster or a vector modulator. By generating the pre-distortion parameters at baseband, while pre-distorting the input signal at non-baseband, the amplifier system avoids the cost and inaccuracies associated with analog signal delay and RF power detection of prior-art "all-RF" pre-distortion implementations, while avoiding the wider-bandwidth filtering of prior-art "all-baseband" pre-distortion implementations.