Baseband pre-distortion power amplifier linearization method based on one-way feedback and non-iterative technique

Abstract

The invention discloses a baseband pre-distortion power amplifier linearization method based on one-way feedback and a non-iterative technique, belonging to the technical field of electronics and relating to a power amplifier linearization technique. Two orthogonal training sequences of linearly increased amplitudes are input into a power amplifier successively, and an improved look-up table is constructed by an I path feedback signal sequence output by power amplifier; the input signals of the whole power amplifier system calculates and looks for corresponding look-up table values by the amplitudes, then corresponding pre-distortion process is carried out on the I path and Q path baseband input signals, and the input signals after pre-distortion are output to the power amplifier after D / A conversion, filtration and up-conversion, thus obtaining the output signals which show linear amplification with the baseband input signals of the whole power amplifier system. The whole pre-distortion process can be realized in a digital processing chip (comprising DSP or FPGA). Compared with the prior art, the method does not need arctangent or inverse cosine calculation and does not need coordinate transformation, thus reducing calculation amount, increasing calculation efficiency and ensuring the system structure to be simpler.

Description

technical field [0001] The invention belongs to the field of electronic technology, and relates to a linearization technology of a power amplifier, in particular to a linearization method of a broadband radio frequency power amplifier based on a digital baseband predistortion technology. technical background [0002] The idealized power amplifier should be a linear device, that is, for an input signal x(t)=r e jθ (r is the amplitude of the input signal, θ is the phase of the input signal), the output signal y(t)=K·r·cos(ωt+θ) (K is the gain of the ideal linear power amplifier, ωcarrier angular frequency). However, the actual power amplifier is a nonlinear device, for an input signal x(t)=re jθ , its output signal is y(t)=B(r) cos(ωt+θ+Φ(r)), where B(r) is the amplitude function of the output signal of the nonlinear power amplifier, and Φ(r) is the nonlinear power amplifier The additional phase function of (research shows that both the gain and the additional phase of the n...

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Problems solved by technology

[0022] The main disadvantage of this non-iterative method is that the IQ signal needs to be converted into polar coordinates during pre-distortion processing, and the amplitude and phase are respectively corrected according to the amplitude of the input signal, and the corrected polar coordinates signal needs to be converted into The form of the IQ signal, therefore, the pre-distortion process needs two coordinate transformations to complete, and after obtaining the look-up table parameter θ i The arctangent operation is required in the process, and the operation is more complicated

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