Distortion compensation circuit, transmitting apparatus and distortion compensating method

摘要

A distortion compensation circuit for compensating for the distortion characteristics of an amplifier, includes a distortion compensating coefficient calculating element and a distortion compensating operation element. The distortion compensating coefficient calculating element calculates a distortion compensating coefficient to be used for compensation of the distortion characteristics by comparing an input signal with the output signal amplified by the amplifier. The distortion compensating operation element performs a distortion compensating operation on the input signal, using a variably set bit format and the distortion compensating coefficient calculated by the distortion compensating coefficient calculating element.

主权项

1. A distortion compensation circuit for compensating for distortion characteristics of an amplifier, comprising:
a distortion compensating coefficient calculator that calculates a distortion compensating coefficient to be used for compensation of the distortion characteristics by comparing an input signal with an output signal amplified by the amplifier; a bit format determiner that sets up a bit format with a predetermined number of bits that expresses a numerical value of a target signal having a first precision with a different, second precision; a distortion compensating operation unit that performs a distortion compensating operation on the input signal, using the bit format set by the bit format determiner and the distortion compensating coefficient calculated by the distortion compensating coefficient calculator; a distortion compensation-operated maximum amplitude calculator that calculates, based on the distortion compensating coefficient calculated by the distortion compensating coefficient calculator, a maximum amplitude of a distortion-compensated signal input to the amplifier, determined depending on an amount of compression at a saturation output point of the amplifier; and a bit format determiner that sets up the bit format so as to be able to express the maximum amplitude calculated by a distortion compensation-operated maximum amplitude calculator.