Influence analysis of digital pre-distortion technology on specific emitter identification

In the field of specific emitter identification (SEI), power amplifiers (PAs) have long been recognized as significant contributors to unintentional modulation characteristics. To enhance signal quality, digital pre-distortion (DPD) techniques are commonly employed in practical applications to mitigate the nonlinear effects of PAs. However, DPD techniques may diminish the distinctive characteristics of individual transmitters, potentially compromising SEI performance. This study investigates the influence of SEI in the presence of DPD applied to PAs. We construct a semi-physical emitter platform using AD9361 and ZYNQ, incorporating memory and non-memory models to emulate an amplification system comprising DPD devices and PAs. Furthermore, we delve into the analysis and evaluation of LMS-based and QRD-RLS-based DPD algorithms to ascertain their efficacy in compensating for amplifier nonlinearity. Finally, we conduct a comprehensive set of experiments to demonstrate the adverse impact of DPD techniques on SEI. Our findings demonstrate a direct correlation between the degree of DPD performance and its impact magnitude on SEI, thereby providing a foundational basis for future studies investigating SEI techniques under DPD.