Sequential asymmetric superposition windowing for Crest Factor Reduction and its effects on Doherty power amplifier

This paper investigates the effect of the application of a window based Crest Factor Reduction (CFR) technique in conjunction with Volterra based Digital Predistortion (V-DPD) technique method on a Doherty power amplifier (DPA). Spectra regrowth, Peak to Average Power Ratio (PAPR) reduction and Error Vector Magnitude (EVM) have been used to evaluate the performance of the proposed approach. From the simulation and experimental results, it is evident that the combination of CFR plus V-DPD is able to reduce the PAPR of the input signals by nearly 60%, with minimal deterioration in the EVM. Moreover, it allows to over-driving the DPA by 2.0 dB, resulting in an average efficiency enhancement of about 40%, while fulfilling the requirements of long-term evolution (LTE) standards.