A digital predistortion online training method for wireless frequency hopping communication system

Abstract

The invention discloses a digital pre-distortion (DPD) online training method for a wireless frequency hopping communication system. Offline training is firstly carried out, the frequency range of frequency hopping is divided into several frequency bands, each frequency band is trained to obtain a corresponding power amplifier DPD coefficient, and pre-storage is carried out; and then, online training is carried out, a DPD model obtained by training in a certain small frequency band is used to replace a nearby DPD model in a larger frequency band, and online DPD system updating is realized. Inthe DPD technology, a power amplifier linearity correctable model is firstly acquired from training in input signals and feedback signals of the power amplifier, the input signals of the power amplifier are then subjected to pre-distortion processing in a digital domain according to the DPD model, the power amplifier does not return too much while the final output signals of the power amplifier meet an out-of-band leakage index, and the power amplifier efficiency is thus ensured.

Description

technical field [0001] The present invention relates to the field of wireless frequency hopping communication, more specifically, to an online digital predistortion training method for a wireless frequency hopping communication system. Background technique [0002] With the evolution of wireless communication to broadband, the peak-to-average ratio of the modulated transmitted signal is generally large, and when a signal with a certain peak-to-average ratio passes through the power amplifier, the power amplifier needs to back off to ensure the out-of-band leakage of the amplified signal (Linearity) will not exceed the standard, but this will lead to a reduction in the efficiency of the power amplifier, which will consume more power supply energy. DPD (Digital Pre-distortion, digital pre-distortion) is a better technical means proposed to solve the contradiction between power amplifier linearity and power amplifier efficiency. [0003] The DPD technology first trains and obt...

AI Technical Summary

Problems solved by technology

Although this method can achieve the effect of real-time correction, as the power amplifier ages, the linearity, gain, group delay and other characteristics of the power amplifier will slowly change, and the frequency hopping DPD model will gradually not match the power amplifier model, and the system will lose the effect of improving the linearity of the power amplifier.

Therefore, in order to ensure that the DPD model matches the power amplifier model, the frequency-hopping DPD coefficients must be updated offline every once in a while. The inability to train the DPD coefficients online makes the frequency-hopping DPD application of this method very limited.

[0006] This patent specially designs a DPD online training method for wireless frequency hopping communication systems according to the characteristics of the frequency hopping wireless communication system, such as fast frequency hopping rate, large communication frequency octave range, and current DPD online training difficulty.

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