Digital predistortion of a power amplifier for signals comprising widely spaced carriers

Digital predistortion (DPD) of a RF power amplifier (PA) for signals comprising two widely spaced carrier clusters is proposed. The basis waveforms within the DPD are selected to allow for the use of a lower sampling rate. Multi-carrier signals spanning 60 MHz of bandwidth are linearized using a sample rate of 100 MHz for the transmitter and observation paths, as oppose to a sample rate exceeding 300 MHz (5 times Nyquist) used conventionally. A transmit (Tx) filter located after the PA attenuates intermodulation distortion (IMD) falling outside of the 100 MHz of correction bandwidth provided by the DPD.