FPGA Implementation of Adaptive Baseband Predistortion for FET-Based Wireless Power Amplifiers

A FPGA-based baseband predistortion scheme is discussed and applied to the linearization of a representative advanced power amplifier, a Si LDMOS power amplifier for basestation applications. Promising results are obtained regarding the efficiency and linearity performance improvement with modulated input signals following the W-CDMA 3GPP standard. The paper proposes a new parallel pipelined architecture for implementing the digital predistorter, using a 28-bit fixed point arithmetic representation. The predistorter is implemented on a Xilinx Xtreme DSP Virtex-4 FPGA board.