Adaptive NLMS pre-distorter of HPA with memory effect

Single carrier M-APSK modulation technique is well used in satellite communication system due to the low PAPR so that the we can expect more resistance to the non-linear distortion. Although TWTA has high amplification efficiency, it may produce serious non-linear distortion. Memory effect that can be observed in the very high speed data rate would be another harmful effect. In this paper, to compensate non-linear distortion efficiently in case of HPA model with the memory effect, we design adaptive pre-distorter using NLMS (normalized least mean square) algorithm. Through the simulation, we confirm that the pre-distorter using NLMS algorithm is able to improve the BER performance than existing pre-distorter.