Patent ID: 9647704
Date: 2017-05-09
CPC Classifications: H03F,H04B

Claim:
1. A digital predistortion system based on envelope tracking, comprising: a digital predistorter, configured to receive a digital signal, and perform predistortion processing on the digital signal to obtain a predistortion signal; a digital-to-analog converter, configured to receive the predistortion signal, and convert the predistortion signal into an analog signal; a frequency mixer, configured to receive the analog signal from the digital-to-analog converter, and modulate the analog signal to obtain a radio frequency input signal; a power amplifier, configured to receive a supply voltage, and amplify the radio frequency input signal under function of the supply voltage to obtain a radio frequency output signal; and a power supply apparatus, configured to receive the predistortion signal, and generate the supply voltage based on the predistortion signal; wherein the digital predistorter is capable of working in multiple processing manners, wherein the multiple processing manners comprise a first processing manner and a second processing manner being different from the first processing manner; wherein a first value range of the predistortion signal that is obtained when the digital predistorter works in the first processing manner is within a first interval, and a second value range of the predistortion signal that is obtained when the digital predistorter works in the second processing manner is within a second interval; when the digital predistorter obtains the predistortion signal whose value range is within the first interval, a value of the supply voltage generated by the power supply apparatus is M when the digital predistorter obtains the predistortion signal whose value range is within the second interval, a change of the supply voltage generated by the power supply apparatus tracks a change of an envelope signal of the predistortion signal, and the power amplifier works in a non-linear region; and under function of a predistortion gain of the digital predistorter and an amplification gain of the power amplifier, a system gain of the radio frequency output signal relative to the digital signal is a constant, wherein the predistortion gain reflects a change of the predistortion signal relative to the digital signal, and the amplification gain reflects a change of the radio frequency output signal relative to the radio frequency input signal.