Digital predistortion tailored to specified frequencies in the power amplifier (PA) output spectrum

A power amplifier (PA) system, comprises:

• a PA circuit configured to receive a PA input signal and amplify the PA input signal to generate a PA output signal based thereon;
• a coefficient estimation circuit, comprising:
• a first transformation circuit configured to receive a PA input comprising a processed version of the PA input signal associated with the PA circuit and process the PA input based on a first predetermined weighted function, to form a processed PA input;
• a second transformation circuit configured to receive a PA output comprising a processed version of the PA output signal associated with the PA circuit and process the PA output based on a second predetermined weighted function, to form a processed PA output;
• and
• a coefficient computation circuit configured to:
• receive the processed PA input and the processed PA output;
• and
• estimate distortion coefficients to be utilized for predistorting the PA input signal, based on the processed PA input and the processed PA output.

A method for applying digital predistortion (DPD) to a power amplifier (PA) circuit, comprising:

• receiving a PA input comprising a processed version of an input signal of the PA circuit and processing the PA input based on a first predetermined weighted function, to form a processed PA input, at a first transformation circuit;
• receiving a PA output comprising a processed version of an output signal of the PA circuit and processing the PA output based on a second predetermined weighted function, to form a processed PA output, at a second transformation circuit;
• and
• receiving the processed PA input and the processed PA output, and estimating distortion coefficients to be utilized for predistorting the input signal of the PA circuit, based on the processed PA input and the processed PA output, at a coefficient computation circuit.