Bandpass sampling schemes for observation receiver for use in PA DPD system for concurrent multi-band signals

摘要

The present disclosure relates to an undersampling observation receiver for use in a power amplifier digital predistortion system for concurrent multi-band signals. In one embodiment, an undersampling observation receiver receives a concurrent multi-band signal output by a power amplifier. The concurrent multi-band output signal includes multiple original frequency bands. The;undersampling observation receiver undersamples the concurrent multi-band signal at a select sampling rate to provide an undersampled multi-band signal. The select sampling rate is such that a frequency-flipped image of at least one of the original frequency bands and images of any remaining original frequency bands fall within a frequency range of zero to half of the select sampling rate and do not overlap one another.