Patent ID: 7924942

Claim:
A training method for a power amplifier pre-distorter formed by a FIR filter structure, wherein the FIR filter structure includes an individual look-up table for each filter tap, the method comprising: selecting, from each filter tap of the individual look-up table, a filter coefficient that depends on an amplitude of a corresponding complex signal value to be multiplied by the filter tap; determining a first estimate of a first look-up table assigned to a first filter tap, assuming a second look-up table assigned to a second filter tap is set to predetermined table values; and determining a second estimate of the second look-up table assuming the first look-up table is set to the determined first estimate, wherein each look-up table represents a discretized polynomial in a variable representing the signal amplitude of an input signal to the FIR filter structure, and wherein the filter coefficient selected from the look-up table corresponding to each filter tap is independent of complex signal values to be multiplied by other filter taps.