Joint Optimization of Guard-Band-Confined Peak Reduction and DPD for Boosting PA Average Output Power

This paper proposes a novel joint linearization framework that integrates a guard-band-assisted peak reduction signal generator (PRSG) with a digital predistortion (DPD) module to boost the average output power of a power amplifier (PA) in next-generation wireless systems. High peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) signals necessitates significant input back-off (IBO), compromising energy efficiency and output power. To overcome the limitations of conventional cascaded crest factor reduction (CFR) and DPD approaches, particularly under overdrive re- gions, we present a U-Net-based PRSG that generates peak- cancellation signals strictly confined to guard bands, thereby preserving in-band signal quality. By employing a three-stage collaborative training strategy with a neural network (NN)-based DPD, the proposed method enables successful linearization even when signal peaks exceed the PA’s saturation power.