To provide an adaptive predistortion type distortion compensation power amplifier in which convergence time at cold start is shortened by reducing memory capacity and power efficiency is maximized within a range where an adjacent channel leak power ratio satisfies a legal value.
Expansion into complex power series is used to model an input-output characteristic of a power amplifier and an input-output characteristic of a predistortion amplifier for performing predistortion processing, and a fundamental wave coefficient of the predistortion amplifier, that is, the backoff of an input signal of the predistortion amplifier is controlled so as to be maximized within the range where an adjacent channel leak power ratio of the power amplifier does not exceed the legal value.
ARAKI ATSUMICHI
KOBAYASHI TOKIO
GIGATEC KK
Sadayoshi Igarashi
Susumu Kitano
Akio Ishii