A Narrowband Feedback Digital Predistortion System and Method

Abstract

The invention discloses a digital predistortion system and method for narrowband feedback. The system includes a digital predistorter, a digital-to-analog conversion module, a power amplifier, a filter, an analog-to-digital conversion module, and a predistortion parameter estimation module; the digital predistorter The input end of the signal source is connected to the signal source, and its output end is connected with the digital-to-analog conversion module and the predistortion estimation module respectively; The output end of the digital-to-analog conversion module is connected with the power amplifier, and the output end of the power amplifier is connected with the signal output device and the filter respectively; The output terminal is connected to the predistortion parameter estimation module through the analog-to-digital conversion module, and the output terminal of the predistortion parameter estimation module is connected to the digital predistorter. In the present invention, the signal output by the power amplifier is filtered, and after reducing the signal bandwidth, digital-to-analog conversion and pre-distortion parameter extraction are carried out, so that the digital pre-distorter can perform pre-distortion adjustment, reduce the bandwidth of the feedback path, and reduce the rate of analog-to-digital conversion On the basis of system power consumption and cost, the linearity index of the power amplifier is guaranteed.

Description

technical field [0001] The invention relates to a digital predistortion system and method for narrowband feedback. Background technique [0002] The power amplifier (PowerAmplifierPA) is one of the core components in the modern mobile communication system, and its performance directly affects the performance of the wireless communication system. To improve efficiency, amplifiers usually operate in a high-efficiency region close to the saturation point, where nonlinear characteristics exist in the amplifier. Since the current communication signal has a non-constant envelope, intermodulation distortion and spectrum growth will occur after nonlinear amplification, which will cause adjacent channel interference and deteriorate the bit error rate of the receiver. To solve this problem, a digital pre-distortion (Digital Pre-DistortionDPD) technology has emerged. With the assistance of pre-distortion technology, the power amplifier can work near the saturation point and maintain ...

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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