A robust and low sampling rate digital predistortion algorithm for broadband PA modeling and predistortion

摘要

A robust and low sampling rate digital predistortion (DPD) algorithm for broadband power amplifiers (PAs) is proposed in this paper. To alleviate the burden on the sampling rate, an approximated model extracted by bandlimited signals is employed to approach the broadband behavior. Due to the assistance of the low pass filter (LPF) in the feedback loop and the adaptive basis function scheme, the sampling rate can be reduced drastically and the algorithm is more robust. Experimental results show that more than 21 dB adjacent channel power ratio (ACPR) improvement is achieved for 60MHz 3-carrier LTE signal application only with 92.16Msps sampling rate, and the cavity RF filter in the feedback loop is not necessary any more.