Apparatus and method for realizing digital predistortion

Abstract

The invention discloses an apparatus and method for implementing digital predistortion, wherein the method includes utilizing programmable logic structure to realize the following steps: S1. a parameter control module utilizes power amplifier incoming signals and power amplifier feedback signals of a power amplifier to synchronously calculate and renovate all power amplifier model parameters in the memorization multinomial model; S2. a model copy module assigns the value of the power amplifier model parameter to the corresponding model parameters a digital predistortion module; S3. the digital predistortion module carries out a predistortion process to the incoming signals according to model parameters. The inventive apparatus and method utilizes parallel arithmetic advantage of the programmable logic structure, thereby realizing the calculation of all model parameters in an instruction cycle, reducing computing time, improving predistortion process efficiency, and quickly and accurately realizing the digital predistortion process.

Description

technical field [0001] The present invention relates to the pre-distortion technology in the field of communication, in particular to a device and method for realizing digital pre-distortion. Background technique [0002] At present, the problem of nonlinear distortion brought by radio frequency power amplifiers has attracted more and more attention. A more mature approach is to use digital pre-distortion technology in conjunction with signal peak-to-average ratio control technology to maintain system linearity. The basic principle of this method is that the signal first passes through the digital pre-distortion module to generate a nonlinear distortion opposite to the distortion of the power amplifier, so that the distorted signal is converted into an undistorted signal output when it passes through the power amplifier. See figure 1 . [0003] As far as the typical way of using the gain lookup table to realize digital predistortion is concerned, the construction of the lo...

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Problems solved by technology

[0004] This method is difficult to implement in practice, has a complicated structure and has the following disadvantages: the calculation of the gain coefficient stored in the lookup table is realized by a digital processor, and the digital processor can complete one multiplication and one addition in one instruction cycle, so It takes a long time to complete the calculation of the gain coefficient; in addition, the gain coefficient stored in the lookup table changes with the power of the feedback signal, but due to the long calculation time, the predistortion system cannot make timely adjustments to signal changes; Moreover, the gain coefficient is recalculated only when the signal power changes greatly, so the gain coefficient multiplied by the predistortion input signal is an approximation of the actual gain curve, which limits the processing capacity of the predistortion system

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