Adaptive digital pre-distortion for future wireless transmitters

Digital pre-distortion techniques are one of the most interesting approaches to break the linearity-efficiency tradeoff of Power Amplifiers. In the recent past, these techniques were exclusively employed in the base stations due to the high computation resources needed for the coefficients estimation. Nowadays, low-complexity DPD techniques are proposed to extend their usage in mobile devices such as tablets and even smartphones. In this paper, we propose a novel low-complexity DPD estimation scheme. The approach consists in using a memoryless polynomial correction to reduce the estimation run time/complexity and to perform a fast reevaluation for each LO frequency in order to mitigate the memory effects. The proposed technique was implemented and validated on PAs off-the-shelf using the AD-FMComms3-EBZ transceiver board and a Kalray MPPA platform. Adjacent Channel Power Ratio improvements of 14 dB were obtained for output powers of 22 dBm.