Distortion compensation table creation method and distortion compensation method

摘要

Fundamentals and IM waves comprising distortion signals are detected by vector measurement from an amplified baseband signal. Detected IM waves are related to power and frequency and plotted on the frequency axis. IM waves related to power and frequency are subjected to IFFT processing, and thereby converted so as to be related to time and power. Amplitude and phase components of IM waves subjected to IFFT processing are found. Compensation signal generation information is generated by relating a distortion compensation signal that has amplitude components of inverse amplitude to the amplitude components of IM waves and phase components of inverse phase to the phase components of IM waves to power, and creating a table by storing the generated compensation signal generation information in a compensation table. By this means, the circuit configuration can be made small and simple, processing can be simplified and speeded up, and distortion components can be suppressed with high precision.