Patent ID: 7746955

Claim:
A power amplifier pre-distorter formed by a discrete-time filter structure with filter taps, wherein said filter structure includes: an individual look-up table for each filter tap, each look-up table representing a sampled polynomial in a variable representing signal amplitude; means for selecting, from each filter tap look-up table a filter coefficient that depends on the amplitude of a corresponding complex signal value to be multiplied by the filter tap; and means for compensating for changes in at least one predetermined parameter, wherein said parameter represents amplifier temperature and said compensating for changes in amplifier temperature is not dependent on memory effects of the amplifier, and wherein pre-distortion (PD(n,z)) for the power amplifier stored in the individual look-up tables is approximated as: PD ⁡ ( n , z ) = ∑ q = 0 Q ⁢ ⁢ x ⁡ ( n - q ) ⁡ [ ∑ m = 0 M - 1 ⁢ ⁢ T qm ⁡ (  x ⁡ ( n - q )  ) ⁢ z m ] where z is the predetermined parameter, q represents time, x(n) is an input signal sample, T qm (|x(n−q)|) is a series of polynomials in the absolute value of the complex variable x(n−q), and M is a number of polynomial terms in the series.