Digital pre-distortion corrector for power amplifier

A circuit comprising:

• a first digital pre-distortion (DPD) corrector having an input and an output;
• a second DPD corrector having an input coupled to the input of the first DPD corrector, and an output, the second DPD corrector including:
• term generator circuitry having a first input coupled to the input of the second DPD corrector, a second input, and an output coupled to the output of the second DPD corrector;
• a signal statistics circuit having an input coupled to the input of the second DPD corrector, and an output coupled to the second input of the term generator circuitry;
• and
• a signal combiner having a first input coupled to the output of the first DPD corrector, a second input coupled to the output of the second DPD corrector, and an output, wherein the signal statistics circuit includes:
• a plurality of statistics generators each having an input and an output, wherein the outputs of the plurality of statistics generators are coupled to the output of the signal statistics circuit;
• and
• a signal mapper having an input coupled to the input of the signal statistics circuit, and an output coupled to the inputs of the plurality of statistics generators.

An apparatus comprising:

• a first digital pre-distortion (DPD) corrector having an input and an output;
• a second DPD corrector having an input coupled to the input of the first DPD corrector, a second input, and an output;
• a signal combiner having a first input coupled to the output of the first DPD corrector, a second input coupled to the output of the second DPD corrector, and an output;
• a digital to analog converter (DAC) having an input coupled to the output of the signal combiner, and an output;
• and
• a power amplifier (PA) having an input coupled to the output of the DAC, and an output;
• wherein the second DPD corrector is configured to provide a signal at the output of the second DPD corrector based on a signal at the input of the second DPD corrector and one or more signal statistics derived from the signal at the input of the second DPD corrector;
• and
• wherein the second DPD corrector comprises a signal statistics circuit that includes:
• a plurality of statistics generators each having an input and an output, wherein the outputs of the plurality of statistics generators are coupled to the output of the signal statistics circuit;
• and
• a signal mapper having an input coupled to the input of the signal statistics circuit, and an output coupled to the inputs of the plurality of statistics generators.

A method for applying digital pre-distortion (DPD) correction to an input signal to produce an output signal, the method comprising:

• generating delayed samples and advanced samples of the input signal using a tap delay line;
• generating a first set of terms based on the delayed samples and the advanced samples of the input signal using a term generator having a plurality of inputs respectively coupled to a plurality of outputs of the tap delay line;
• generating a first set of statistics based on the delayed samples and advanced samples of the input signal using a first signal statistics circuit;
• generating a second set of terms based on the first set of terms and the first set of statistics using a second signal statistics circuit;
• and
• combining the second set of terms to produce the output signal using a term and statistics combiner having a first plurality of inputs respectively coupled to a plurality of outputs of the term generator, a second input coupled to an output of the first signal statistics circuit, and a third input coupled to an output of the second signal statistics circuit.