CDMA/OFDM linearity compliant wireless communication amplifier
A digital pre-distortion system which can provide the flexibility to model the highly non-linear distortion associated with High Efficiency RF Power Amplifiers while through a novel implementation of a least squares estimation process allows an implementation well suited for an FPGA application where limited resources and in particular memory resources are available.
1. A system comprising:
a pre-distorter for introducing distortion into an input signal of an amplifier based on coefficients that are linearly interpolated from a subset of coefficients that are based on a least squares optimized model of time varying non-linearity characteristics derived from samples of the amplifier output for producing a wireless signal that is compliant with at least one wireless standard linearity requirement;
wherein the least squares optimized model comprises:
least squares optimizing each set of a series of limited amplifier output data sample sets;
updating an intermediate matrix for deriving pre-distortion coefficients with each least squares optimized set thereby facilitating optimizing pre-distorter coefficients across a quantity of amplifier output samples that is larger than the limited amplifier output data sample set.