Patent ID: 7864881
Filing Date: 2011-01-04
Classification: H03F,H04L

Abstract:
1. A polynomial predistortor comprising a polynomial basis generation portion for generating a basis vector Xv based on a complex input signal Sx=Ix+jQx and an inner product calculation portion for outputting an inner product Cv·Xv as a polynomial value multiplied by a coefficient vector Cv, wherein the polynomial predistortor delays a real part and an imaginary part of a complex input signal Sx=Ix+jQx for up to M samples to generate 2(M+1) signals, duplicately combines these signals to generate monomials having maximum degree N, outputs, as the basis vector Xv, all or part of the monomials depending or needs, and uses, as the coefficient vector Cv, a set of complex numbers sized equally to the basis vector Xv; and wherein the polynomial predistortor expands Volterra series suitable for description of a nonlinear time-invariant system so that an input signal becomes a complex number Sx=Ix+jQx and an output signal becomes a complex number Sy=IY+jQy.