System and method for digital pre-distortion circuits

An apparatus for signal classification in a digital pre-distortion (DPD) circuit, comprising:

• a first frequency path configured to filter an input signal via a first half-band low pass filter (LPF) after a positive frequency translation and to generate a first power level corresponding to a signal output of the first frequency path;
• a second frequency path configured to filter the input signal via a second half-band LPF after a negative frequency translation and to generate a second power level corresponding to a signal output of the second frequency path;
• a third frequency path configured to filter the input signal via a high pass filter (HPF) and to generate a third power level corresponding to a signal output of the third frequency path;
• and
• a processing unit configured to compute frequency content metrics corresponding to the input signal based on the first power level, the second power level and the third power level for selecting a set of DPD coefficients for the DPD circuit.