Device and method for identifying inverse characteristic of nonlinear system, power amplifier and predistorter thereof

Abstract

The invention discloses a nonlinear system, in particular a device and a method for identifying inverse characteristic of a nonlinear power amplifier, a predistorter of the power amplifier and power amplification equipment using the device for identifying the inverse characteristic of the nonlinear system and the predistorter. The method for identifying the inverse characteristic of the nonlinear system according to an original input signal x(n) and a corresponding feedback output signal y<G>(n) of the nonlinear system comprises the following steps: according to an inverse filter signal x<F> (n) and the feedback output signal y<G>(n), calculating an inquiry form function Q[.]; according to the feedback output signal y<G>(n) and the inquiry form function Q[.], generating a middle predistortion signal z(n); according to the middle predistortion signal z(n) and the original input signal x(n), constructing a filter function F[.]; carrying out inverse filtering on the original input signal x(n) by using parameters of the filter function F[.] to generate an inverse filter signal x<F>(n); repeating each step through iteration till meeting the set condition, wherein the inquiry form function Q[.] and the filter function F[.] represent the inverse characteristic of the nonlinear system.

Description

technical field [0001] The present invention relates generally to nonlinear systems, and in particular to nonlinear power amplifiers, especially for use in transmitters of wireless communication systems such as base stations and mobile stations. More specifically, the present invention relates to a nonlinear system, especially a nonlinear power amplifier inverse characteristic identification device and method, a power amplifier predistorter, and a power amplification device using a nonlinear system inverse characteristic identification device and a predistorter, which mainly utilizes Digital technology implements pre-distortion in the baseband to compensate for the non-memory non-linear and memory characteristics of the non-linear complementary power amplifier. Background technique [0002] As a typical representative of nonlinear systems, power amplifiers are an important part of many electronic devices, which can amplify weak electrical signals to meet the needs of long-di...

AI Technical Summary

Problems solved by technology

However, the two-dimensional look-up table not only requires a large memory to store a large amount of pre-distortion data, but also has a limited memory depth, and often only uses the relationship between the current input and the previous input and output to pre-distort the input signal of the power amplifier. Counteracts memory characteristics of power amplifiers

Multidimensional lookup tables can become very complex and difficult to implement if increased memory depth is required

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