System and method for digital predistortion

A system for digital predistortion (DPD), the system comprising:

• a DPD block with a first input terminal and a first output terminal;
• a power amplifier (PA) having a second input terminal and a second output terminal;
• and
• a transmitter coupling the first output terminal of the DPD block at least indirectly with the second input terminal of the PA,
• wherein the DPD block is configured to receive a first input signal and to provide a first output signal at the first output terminal, and wherein the DPD block includes a Generalized Memory Polynomials (GMP) model that is configured to generate a GMP model output signal based upon the first input signal,
• wherein the DPD block additionally includes a first mixing module that is configured to receive the first input signal at a first input port and the GMP model output signal at a second input port, and to generate a first mixing module output signal based upon the first input signal and the GMP model output signal,
• wherein the DPD block further includes a first summation block that is configured to generate the first output signal at least in part as a first sum of the GMP model output signal and the first mixing module output signal,
• wherein the first mixing module includes a plurality of first finite impulse response (FIR) filters, a plurality of first multiplication blocks, and a second summation block, wherein the mixing module is configured to generate the first mixing module output signal as a second sum of a plurality of intermediate output signals, wherein the respective intermediate output signals are generated by the respective first multiplication blocks as respective products of respective first additional input signals based at least indirectly upon the first input signal and respective second additional input signals based at least indirectly upon the GMP model output signal, and
• wherein at least some of the first and second additional input signals are respectively provided by the respective first FIR filters based at least indirectly upon either the first input signal or the GMP model output signal, and
• wherein each of the first FIR filters includes a respective filter input port, a respective filter output port, a respective plurality of complex-valued coefficients, a plurality of additional multiplication blocks, and a third summation block.

A method of digital predistortion (DPD) for a power amplifier (PA), the method comprising:

• receiving a first input signal at a first input terminal of a digital predistortion (DPD) block that additionally includes a first output terminal;
• performing first processing, at a nonlinear model of the DPD block, so as to generate a nonlinear model output signal based at least indirectly upon the first input signal;
• performing second processing at a first mixing module having a plurality of first finite impulse response (FIR) filters, a plurality of first multiplication blocks, and a first summation block, so as to generate a first mixing module output signal based upon the first input signal and the nonlinear model output signal,
• wherein the second processing includes summing at the first summation block a plurality of intermediate output signals that are respectively generated by the respective first multiplication blocks as respective products of respective first additional input signals based at least indirectly upon the first input signal and respective second additional input signals based at least indirectly upon the nonlinear model output signal,
• wherein either the respective first additional input signals are respectively provided by the respective first FIR filters based at least indirectly upon the first input signal, or the respective second additional input signals are respectively provided by the respective first FIR filters based at least indirectly upon the nonlinear model output signal;
• generating a first output signal at a second summation block at least in part by summing the nonlinear model output signal and the first mixing module output signal;
• and
• providing the first output signal from the first output terminal of the DPD block for receipt by a transmitter coupling the first output terminal of the DPD block at least indirectly with a second input terminal of a power amplifier (PA) having a second output terminal.