Digital predistortion system and method achieving undersampling feedback

Abstract

The invention discloses a digital predistortion system and method achieving undersampling feedback. The system comprise a digital predistorter, a digital-to-analog conversion module, a power amplifier, an analog-to-digital conversion module and a predistortion parameter estimation module; the input end of the digital predistorter is connected with a signal source, and the output end of the digital predistorter is connected with the digital-to-analog conversion module and the predistortion estimation module separately; the output end of the digital-to-analog conversion module is connected with the power amplifier, and the output end of the amplifier is connected with a signal output device and the analog-digital conversion module; the output end of the analog-to-digital conversion module is connected with the predistortion parameter estimation module. According to the digital predistortion system and method, signals output by the power amplifier are converted at the sampling rate lower than the bandwidth of the signals output by the power amplifier, aliasing digital signals are generated, the requirement on the analog-digital conversion rate is lowered, and a predistortion parameter vector is extracted according to the aliasing digital signals to be used for predistortion parameter adjusting of the digital predistorter; the analog-digital conversion sampling rate is decreased, the power consumption and cost of the system are reduced, and meanwhile the linearity index of the power amplifier is guaranteed.

Description

technical field [0001] The invention relates to a digital predistortion system and method for under-sampling feedback. Background technique [0002] The demand for modern wireless communication services is growing rapidly, and wireless communication is required to have high-quality and large-capacity transmission methods, which means that the communication system must adopt efficient linear modulation methods to improve the data rate and spectrum utilization of limited bandwidth, so that the power amplifier The linearization of has become a hot technique. [0003] The traditional technology to solve the linearization of power amplifiers is to use power back-off, feed-forward, negative feedback and pre-distortion technology. The power utilization rate of the power amplifier is low, and a larger power amplifier has to be selected in order to meet the usage requirements for the backed power, which wastes energy and increases costs. [0004] Another analog pre-distortion techn...

AI Technical Summary

Problems solved by technology

According to the traditional feedback path design method, in order to accurately capture the output signal of the power amplifier, the feedback path bandwidth needs to be at least 500MHz, and the corresponding analog-to-digital conversion rate needs to be at least 1000MHz, which greatly increases the difficulty of system implementation and increases the system cost.

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