Amplifier linearization using predistortion

摘要

A device and method of predistortion linearization that account for both EVM and spectral mask are disclosed. The device and method are based on transforming the predistorter optimization problem from the time domain to the frequency domain, and weighting the equations according to one or more desired objectives. One objective focuses on abiding by the spectral mask, whereas another objective focuses on improving the EVM.

主权项

1. A device for linearizing an output of a power amplifier, comprising:
an input interface for receiving a source signal; a circuit operative to apply a predistortion transform to the source signal to generate a predistortion output signal therefrom, said predistortion transform representing an inverse of a nonlinear response of the power amplifier expressed in a frequency domain; including in said predistortion transform a first one or more equations in the frequency domain adapted to linearize the output of the power amplifier constrained by a spectral mask to reduce an error vector magnitude (EVM) of said power amplifier; including in said predistortion transform a second one or more equations in the frequency domain adapted to linearize the output of the power amplifier in a range of frequencies that does not violate a spectral mask requirement; and an output interface for the predistortion output signal.