Mixer impairment correction based on volterra series

摘要

Techniques for compensating for signal impairments introduced by a mixer are discussed. One example system employing such techniques can include mixer predistortion circuitry configured to receive signal in-phase (I) and signal quadrature (Q) components of a signal and to generate a mixer predistortion signal based at least in part on the signal I and Q components, wherein the mixer predistortion signal compensates for nonlinearities caused by a mixer that upconverts the signal. Optionally, imbalance correction circuitry to compensate for gain and phase imbalance and/or skew correction circuitry to compensate for gain and phase skew can also be included.

主权项

1. A system configured for use in a transmitter, comprising:
baseband circuitry that generates a first signal comprising signal in-phase (I) and signal quadrature (Q) components; a mixer that up-converts the first signal into a radio-frequency (RF) output signal, wherein the mixer generates nonlinearities into the RF output signal; mixer predistortion circuitry configured to receive the first signal and generate a mixer predistortion signal to compensate for at least some of the nonlinearities based at least in part on the signal I and Q components of the first signal; a radio-frequency amplifier that receives and amplifies the RF output signal; and skew correction circuitry configured to receive the signal I and Q components of the signal and to generate a skew correction signal based at least in part on the signal I and Q components, wherein the skew correction signal compensates for a gain and phase skew caused by the mixer, wherein the skew correction circuitry is additionally configured to receive at least one time-delayed signal I component and at least one time-delayed signal Q component, wherein the skew correction signal is based at least in part on the at least one time-delayed signal I component and the at least one time-delayed signal Q component, and wherein the skew correction signal comprises a skew correction I component and a skew correction Q component, wherein each of the skew correction I component and the skew correction Q component are linear combinations of the signal I component, the signal Q component, the at least one time-delayed signal I component, and the at least one time-delayed signal Q component.