Linearization using efficient complex polynomial evaluations

Wideband wireless communications base stations could benefit from efficient arithmetic algorithms for cost effective digital baseband computations. Power amplifiers are ubiquitous in such systems and exhibit nonlinearity, causing spectral growth and in-band distortion, which in turn increase error rates. A digital predistorter compensates for nonlinear effects in the power amplifier by transforming the signal with a complex-valued polynomial (linearization). This requires a fast and efficient evaluation scheme for complex polynomials. In this paper, digit-serial techniques for evaluating linearization transformations are presented. Our contributions include algorithmic techniques for increasing throughput and experimental results for FPGAs.