IN a terrestrial broadcasting or wireless communication system,
the overall power efficiency is mainly determined by
the PA. However, the PA is approximately linear only over a
small range of input, where the power efficiency is not satisfactory.
In order to improve the power efficiency, the PA usually
works in its nonlinear region. The nonlinearity generates both
in-band distortion and out-of-band spectral regrowth. The inband
distortion degrades the error vector magnitude (EVM),
whereas the out-of-band component increases the adjacent
channel interference (ACI) [1], [2].