Impact of subband quantization on DPD correction performance

Abstract : The digital predistortion (DPD) is a technique to linearize the response of power amplifiers which is the subject of an active research. In order to model accurately and properly linearize the PA, the ADC in the feedback path must digitize the distorted signal with an adequate resolution and bandwidth. The multi-stage noise band cancellation (MSNBC) ΣΔ architecture is able to provide a signal digitized by subbands and where the subbands may be digitized with different resolutions. We show that the correction performance can be maintained while different quantization for the main high power subband and for the low power subbands are used resulting in a more flexible and low power consumming solution.