Method of correcting nonlinearities of an amplifier, and radio transmitter employing a method of this type

摘要

The method involves use of a table which associates a complex predistortion digital signal (d) with each value of a complex digital input signal (m). The predistortion signal is modulated to obtain a radio signal which is provided the amplifier. During an adaptation period, a fraction (r') of the amplified radio signal is demodulated and compared with the input which has an associated complex modulated predistortion signal. The table associates a modulus and phase shift of the predistorted signal with each quantised value of the complex input signal. The mean differences in modulus and phase between the complex demodulated and input signals is calculated for the sample blocks in the adaptation period.