Patent ID: 6973139
Filing Date: 2005-12-06
Classification: H03F,H04B,H04L

Abstract:
1. A base station transmitter, comprising: a predistortion unit that predistorts first and second phase digital input signals I (In-phase) and Q (Quadrature); an up-converting unit that converts digital output signals of the predistortion unit into an RF (Radio Frequency) signal; a power amplifier that amplifies a power of the RF signal outputted from the up-converting unit; a down-converting unit that converts an output signal of the power amplifier into a digital signal; a High Power Amplifier (HPA) modeling unit that produces a coefficient of a non-linear characteristic model of the power amplifier using signals obtained by delaying outputs of the predistortion unit for a predetermined time and the digital signal outputted from the down-converting unit; a reference signal generation unit that generates reference signals independent of the first and second phase digital input signals I and Q to produce a predistortion model; and a digital adaptive control unit that extracts an error function using the reference signals and the produced coefficient, wherein the digital adaptive control unit controls characteristics of the predistortion unit adaptively using the error function.