Patent ID: 8355462

Claim:
A communications system employing a high power amplifier driven at or near saturation, having a first source signal and a second source signal, the first source signal being on a first channel and including M symbols, where M is an integer greater than 2, and the second source signal being on a second channel, the communication system comprising: a first modulator unit operable to generate a first modulated signal based on the first source signal, and including a first inter-symbol distortion estimating unit and a first stage predistortion unit; and wherein the first inter-symbol distortion estimating unit is operable to generate a predistorted symbol vector based on an estimate of a distortion of the first through (a−1)-th symbols and an estimate of a distortion of the (a+1)-th through M-th symbols, where 1≦a≦M; wherein the first stage predistortion unit is operable to generate a predistorted symbol ã based on the a-th symbol of the M symbols and the predistorted symbol vector; and wherein the first modulator unit further comprises a second stage predistortion unit operable to further predistort the predistorted symbol ã based on the a-th symbol of the M symbols, the predistorted symbol vector and the predistorted symbol ã.