Patent ID: 6980604

Claim:
A transmission device for predistorting a digital input signal in order to compensate nonlinear distortion produced by an amplifier, then converting said digital input signal into an analog signal, and amplifying said analog signal by means of said amplifier, and transmitting the amplified analog signal, comprising: a first digital/analog converter for converting said digital input signal into a first analog signal; a distortion-compensating signal generator for generating a distortion-compensating signal from said digital input signal and a predistortion signal, said predistortion signal being generated by predistorting said digital input signal on the basis of a distortion-compensation coefficient determined from said digital input signal supplied as a reference signal, and a feedback signal fed back from the output of said amplifier; a second digital/analog converter for converting the distortion-compensating signal generated by said distortion-compensating signal generator into a second analog signal; an adder for adding said second analog signal to said first analog signal and supplying the added analog signal to said amplifier; and a first phase difference compensator for compensating any phase difference in said transmission device other than phase distortion included in said nonlinear distortion of said amplifier for said feedback signal, said phase difference being detected on the basis of said feedback signal and said reference signal, and supplying a phase difference-compensated feedback signal to said distortion-compensating signal generator.