Digital pre-distortion using Legendre polynomials for band 25 transmitters

Abstract

In this paper, we discuss the implementation of a digital pre-distorter for wideband wireless applications using Legendre polynomials as the orthogonal polynomial basis. The implementation discusses a multicarrier configuration using a wideband amplifier. Structures based on polynomial functions are widely used for both power amplifiers (PA's) and predistorters. Higher non-linear orders in the structure tend to increase the numerical stability. Pre-distorters based on orthogonal basis which is discussed based on orthogonal polynomials. The orthogonal polynomial basis discussed is robust and stable and meets the spectral emissions requirements with regards to the adjacent channel power ratio (ACPR).