A modified piece-wise polynomial pre-distortion is proposed, investigated and compared against classic memoryless polynomial pre-distortion. The proposed enhanced piece-wise polynomial pre-distortion uses the overlap between segments to ensure continuity in the total pre-distortion function. The implementation of overlap allows the use of a simple error estimation algorithm to minimise hand over error. The classic and proposed piece-wise pre-distortion performances are assessed and compared for several sets of polynomial coefficients. The proposed method is shown to consistently outperform classical polynomial pre-distortion in terms of required coefficients and linearity improvement. The method is applied for the linearisation of an envelope tracking Class-J PA at 1.7GHz, under a 1.4MHz LTE signal with a 14.4dB PAPR.
Ben Smida, S., Mimis, K., Morris, K. A., Beach, M. A., McGeehan, J. P., Lees, J., Benedikt, J., & Tasker, P. J. (2012). Overlapped segment piece-wise polynomial pre-distortion for the linearisation of power amplifiers in the presence of high PAPR OFDM signals. In 2012 IEEE/MTT-S International Microwave Symposium Digest IEEE. https://doi.org/10.1109/MWSYM.2012.6259543