FPGA Implementation of a LUT-based Digital Predistortion
Application Notes
The Keysight Technologies, Inc. M3602A FPGA Design Environment simplifies the development of custom processing functions for the following PXIe modules: M3100A, M3102A, M3201A, M3202A, M3300A, M3302A with -FP1 (FPGA Programming) option enabled and one of the options -K32 (Kintex-7 K325T FPGA) or -K41 (Kintex-7 K410T FPGA) for the logic. The user-friendly graphical environment simplifies the development of custom DSP for the FPGA device enabling special modes of operation or new control structures. This application note demonstrates the implementation of a signal transformation using a lookup table (LUT). The LUT is filled with the first-order Taylor’s polynomial coefficients (y = ax + b) to implement a piecewise first-order linear approximation of any nonlinear function. As a simple example, this demo implements a sin(x) function into the lookup table to transform a sawtooth source signal into a sinus output signal.