Baseband digital predistortion using subband filtering technique

This paper proposes a subband baseband digital predistortion architecture for power amplifiers operated in multi-channel wideband applications. The new architecture is composed of a cascade of a fixed nonlinear function and an adaptive linear subband filter bank. It takes advantage of subband filtering for computational complexity reduction and convergence enhancement. This will allow digital baseband predistortion to be applied to wideband signals that traditional architectures fail to handle due to the insufficient processing speed capacity of the available digital signal processors. Power amplifiers non-linear behavior changes versus temperature were used for a first attempt to evaluate this new subband predistorter performances.