Patent ID: 6751268
Filing Date: 2004-06-15
Classification: H03F,H04L

Abstract:
A method of predistorting a complex baseband signal having an in-phase component I and a quadrature component Q, said method comprising the steps of:sampling the complex baseband signal to obtain k samples of the in-phase component Ik and of the quadrature component Qk; for each of the k samples determining a respective distortion factor Dk, wherein for each of the k complex samples the respective distortion factor Dk is determined as Dk=atanh (xk)/xk, where xk is the magnitude of the sample k of the baseband signal; multiplying each sample of the in-phase component Ik and of the quadrature component Qk by its respective distortion factor Dk to obtain a predistorted in-phase component sample and a predistorted quadrature component sample; up-converting each of the predistorted in-phase component samples and each of the predistorted quadrature component samples to provide an up-converted, sampled in-phase signal and an up-converted, sampled quadrature signal; and combining the up-converted sampled in-phase signal and the up-converted sampled quadrature signal to provide a predistorted baseband signal.