Digital predistortion processing method and system

Abstract

The invention discloses a digital predistortion processing method and system. The method includes: extracting a predistortion parameter corresponding to an input signal from a predistortion coefficient parameter table, performing predistortion processing on the input signal, and obtaining a forward transmission signal; Performing power amplification processing on the forward transmission signal to obtain an output signal; collecting the output signal to obtain a feedback signal; delaying a predetermined number of sampling points to collect the forward transmission signal to obtain a reference signal; The signal and the feedback signal are synchronously correlated, and the feedback signal is calibrated; the pre-distortion coefficient is trained according to the reference signal and the calibrated feedback signal; the pre-distortion coefficient parameter is formed according to the amplitude of the pre-distortion coefficient and the input signal surface. In this embodiment, the transmission signal is delayed by a predetermined number of sampling points, so that the radio frequency index ACPR is relatively greatly improved.

Description

technical field [0001] The present invention relates to the technical field of communications, in particular to a digital predistortion processing method and system. Background technique [0002] In wireless communication systems, it is often required that the output of the power amplifier (Power Amplifier, PA) has a high linearity to meet the stringent requirements of the air interface standard, but the efficiency of the linear PA is very low and very expensive, while the high-efficiency nonlinear PA will Intermodulation components such as 3rd, 5th, and 7th orders are generated, which will interfere with adjacent channels. In order to improve the output efficiency of the PA and reduce the cost as much as possible, the nonlinear characteristics of the PA must be corrected, and it is a good choice to perform pre-distortion processing on the input signal of the PA. [0003] The essence of digital predistortion (Digital Predistortion, DPD) is to perform predetermined anti-dist...

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Problems solved by technology

However, after the pre-distortion synchronization, it is not mentioned whether to further out-of-sync processing and correction of the synchronized signal, so it is impossible to improve the DPD effect through delay

[0014] Since the input signal is usually a low-speed baseband signal, but digital pre-distortion needs to work at a high rate, it is necessary to interpolate and filter the input baseband signal to increase the rate of the input signal. In order to obtain a better pre-distortion effect, it is usually necessary to use The input signal is interpolated to increase the input signal rate. For example, the interpolation factor of LTE-Time Division Duplexing (TDD) is 48, and the intermediate frequency rate is 245.76MHz. However, a problem brought about by this is that the delay needs to be very accurate. can be accurate to one clock cycle

On the one hand, it is difficult to measure the loopback time of the link in the existing technology; Jitter will cause relatively large errors in pre-distortion processing

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