Adaptively controlled digital pre-distortion in an RF power amplifier using an integrated signal analyzer with enhanced analog-to-digital conversion

摘要

A pre-distortion circuit for a power amplifier may include: (a) a digital interface for receiving a complex-value digital baseband signal; (b) a mixed-signal pre-distortion circuit adaptively controlled by a set of parameter values, receiving the complex-value digital baseband signal to provide a pre-distorted signal for input to the power amplifier, the mixed-signal pre-distortion circuit may include: (i) digital pre-distortion circuit that transforms the complex-value digital baseband signal to a pre-distorted complex-value digital baseband signal by applying to the complex-value digital baseband signal a memory-less non-linear gain and a polynomial function based on the complex-value digital baseband signal one or more delayed copies of the complex-value digital baseband signal; and (ii) up-converter that converts the pre-distorted complex-value digital baseband signal to the pre-distorted signal; and (c) a signal analyzer receiving an output signal from the power amplifier to provide the parameter values from time to time to the mixed-signal pre-distortion circuit.

主权项

1. A pre-distortion circuit for a power amplifier, comprising:
a digital interface for receiving a complex-value digital baseband signal; a mixed-signal pre-distortion circuit adaptively controlled by a set of parameter values, receiving the complex-value digital baseband signal to provide a pre-distorted signal for input to the power amplifier, the mixed-signal pre-distortion circuit comprises:
a digital pre-distortion circuit that transforms the complex-value digital baseband signal to a pre-distorted complex-value digital baseband signal by applying to the complex-value digital baseband signal a memory-less non-linear gain and a polynomial function based on the complex-value digital baseband signal and one or more delayed copies of the complex-value digital baseband signal;an up-converter that converts the pre-distorted complex-value digital baseband signal to the pre-distorted signal; andan over-sampler that increases a data rate in the complex-value digital baseband signal by at least a factor of 2; and a signal analyzer receiving an output signal from the power amplifier to provide the parameter values from time to time to the mixed-signal pre-distortion circuit.