Analytical method of fractional sample period synchronisation for digital predistortion systems

Abstract

As the data throughput is still increased in the wireless communication systems, it is required to efficiently utilise the radio frequency spectrum which usually requires linear transmitters. Consequently methods as a digital predistortion (DPD) are developed to linearise nonlinear power amplifiers. To extract precise parameters for the DPD it is essential to finely synchronise measured feedback signal with the known transmitted signal. In this paper we propose an analytical method for the fractional sample period time synchronisation suitable for DPD signals. Finally benefits of the proposed method are presented on results of its usage for the DPD linearisation using a measurement test-bed.