NONLINEAR DISTORTION COMPENSATING TRANSMITTER CORRECTING AND INTERPOLATING DISTORTION COMPENSATION COEFFICIENT

摘要

PROBLEM TO BE SOLVED: To provide a nonlinear distortion compensating transmitter conducting adaptive pre-distorter type distortion compensation that generates a distortion compensation coefficient with correction or interpolation, reduces a convergence time of the distortion compensation coefficient so as to conduct distortion compensation at a high-speed with high accuracy and decreases a memory capacity of a distortion compensation table. SOLUTION: A complex multiplier 1-2 multiplies a distortion compensation coefficient read from a distortion compensation table 1-1 with an input signal to be sent to provide a pre-distortion to the input signal and the result is outputted through a nonlinear circuit section such as a power amplifier 1-4. The output signal from the power amplifier 1-4 or the like is fed back to the original signal as a feedback signal through an analog/digital converter 1-5, the feedback signal is compared with a transmission signal (reference signal) and an adaptive algorithm is applied to the difference to update the distortion compensation coefficient of the distortion compensation table 1-1. A correction/interpolation device 1-6 applies correction to the distortion compensation coefficient whose convergence takes much time so as to approach the coefficient to a substantial value and generates a desired distortion compensation coefficient through interpolation.