Quantifying and Cancellation Memory Effect in High Power Amplifier for OFDM Systems

This paper is concerned with a new time-domain modeling topology for signals which is appliedto OFDM systems. This model is a more accurate based on Wiener approach. Also the memory effect will be shown using two-tone intermodulation distortion (IMD) measurement with different tone frequency spacing and power levels. Next adaptive predistorter to counterbalance the AM/AM andAM/PM nonlinear effects of the transmitter power amplifier is proposedb y Hammerstein approach. Finally we consider the effectiveness of proposedmetho don performance of OFDM signal as the wideband system by reduction of distortion. It is confirmed by computer simulation that proposedapproac h produces a faster convergence speed than the previous adaptive predistortion technique.