Low Complexity Time Synchronization Based on Digital Predistortion Coefficients

In this letter, we propose an efficient loop-delay estimation approach for digital predistortion (DPD) based on the DPD linear coefficients. The basic concept of our approach consists in considering that the linear coefficients as computed by the DPD act as a linear filter that represents the linear response of the power amplifier, providing very accurate information about loop delay. Our approach has the great advantage of avoiding the need of a dedicated high-precision loop-delay estimator while using DPD. Two different estimators based on the DPD linear coefficients are presented, and their performance characteristics are illustrated on a measurement example using the Chalmers RF WebLab measurement setup.