US 7,733,177 B1 · Method and system for calculating the pre-inverse of a nonlinear system

Abstract

An apparatus is provided to determine pre-distortion for a nonlinear system. The apparatus comprises a datapath and a power amplifier. The datapath employs predistortion data to generally linearized the power amplifier. To generate this predistortion data, an indirect learning circuit and a direct learning circuit can be employed. The indirect learning circuit is generally coupled to the amplifier circuit so that it can iteratively adjust predistortion data during an indirect learning mode until convergence is reached. The direct learning circuit is generally coupled to the amplifier circuit and the indirect learning circuit and that receives the input signal so that the predistortion data can be copied to the direct learning circuit from the indirect learning after convergence is reached and so that the direct learning circuit can adjust the predistortion data during a direct learning mode.

Claims10

Dependent claims

An apparatus comprising:

an amplifier circuit including:
a datapath that receives an input signal;
and
a power amplifier that is coupled to the datapath, wherein the power amplifier receives a first output from the datapath, and wherein the power amplifier provides a second output;
an indirect learning circuit that is coupled to the amplifier circuit, wherein the indirect learning circuit iteratively adjusts predistortion data based at least in part on the first output and the second output during an indirect learning mode until convergence is reached;
and
a direct learning circuit that is coupled to the amplifier circuit and the indirect learning circuit and that receives the input signal, wherein the predistortion data is copied to the direct learning circuit from the indirect learning after convergence is reached, wherein the direct learning circuit adjusts the predistortion data during a direct learning mode, and wherein the direct learning circuit adjusts the operation of the datapath with the predistortion data.

4 more elements

A method for determining a pre-inverse of a nonlinear system, the method comprising:

indirectly adjusting predistortion data during an indirect learning mode until convergence is reached by iteratively:
providing an input signal to a datapath;
providing an output from the datapath to a power amplifier and to an indirect learning circuit;
and
adjusting the predistortion data based at least in part on the output from the datapath and at least in part based on an output from the power amplifier;
copying the predistortion data from the indirect learning circuit to a direct learning circuit;
and
directly adjusting the predistortion data during a direct learning mode after convergence has been reached by iteratively adjusting the predisortion data based at least in part on an output of a power amplifier model.

5 more elements

Dependencies are inferred from the claim text.

Method and system for calculating the pre-inverse of a nonlinear system

Life of this patent

Method and system for calculating the pre-inverse of a nonlinear system

Life of this patent

Abstract

Claims10