Digital pre-distorting power amplifier and implementing method thereof

Abstract

The present invention discloses a digital pre-distortion power amplifier applicable to direct radio frequency signal amplification of mobile communication systems, which comprises a signal processing unit to receive an input signal and transfer the signal to a zero intermediate frequency digital signal, a signal despicking unit to compress a peak-to-average ratio of the zero intermediate frequency digital signal to achieve despicking, a self-adapting pre-distortion power amplification unit to carry out self-adapting digital pre-distortion power amplification to the signal after despicking to output an amplified radio frequency signal. Correspondingly, the present invention also discloses a method to realize digital pre-distortion power amplifier, expands applicable scope of the digital pre-distortion power amplifier, reduces cost on subsequent power amplification equipments, increases power amplification efficiency and simplifies design complexity of power amplifiers.

Description

【Technical field】 [0001] The present invention relates to a power amplifier, in particular to a digital predistortion power amplifier used in a mobile communication system and its realization method. 【technical background】 [0002] With the development of global communication services, communication spectrum resources become more and more precious. In order to make more effective use of spectrum resources, many communication systems use modulation methods with high spectrum utilization, such as QPSK, QAM, etc. These modulation methods not only modulate the carrier phase, but also modulate the carrier amplitude, so there will be A non-constant envelope modulated signal with a large peak-to-average ratio. Even for a constant envelope modulation signal such as GMSK, if multi-carrier technology is used, the synthesis of carriers can also produce a larger peak-to-average ratio, which puts forward higher linearity requirements for the power amplifier. [0003] At present, two me...

AI Technical Summary

Problems solved by technology

[0006] 1. The input signal must be a baseband signal, which limits the application range of this digital predistortion power amplifier, and cannot be applied to devices such as repeaters and tower top amplifiers whose input signals are radio frequency signals

[0007] 2. There is no peak clipping part, which leads to a relatively large peak-average input signal, which increases the cost of the post-stage power amplifier equipment

[0008] 3. When the system is working, the power amplifier works in class A and AB states, which leads to a relatively low working efficiency of the entire digital predistortion power amplifier

[0009] 4. Analog up and down frequency conversion adopts a single local oscillator technology, so it is necessary to add a filter after mixing in the radio frequency path to filter out image interference, which increases the difficulty of system design, and the filter design is more difficult

Images