Linearization method for pre-distorted radio frequency amplifier

Abstract

The invention discloses a linearization method for a pre-distorted radio frequency amplifier, which utilizes a pre-distorted signal generated in the radio frequency field to improve the linearization degree of the amplifier. The method comprises a first link and a second link, wherein the first link is used for carrying out a power amplification on an initial carrier signal, and then combining the amplified signal with an amplified pre-distorted signal of the second link to output a combined signal; the second is used for firstly coupling the initial carrier signal and the combined signal and generating the pre-distorted signal through combining. The pre-distorted signal comprises the initial carrier signal and an intermodulation signal; and power amplification is carried out on the pre-distorted signal equivalent to the first link. The method comprises the following steps: combining the amplified signal of the first link and the amplified pre-distorted signal of the second link to offset the intermodulation signal, outputting a high linear combined signal, and finishing the power amplification process of the initial carrier signal. The method can realize higher working bandwidth and working efficiency and can be applied to different working environments.

Description

【Technical field】 [0001] The invention relates to the technical field of linearization of a power amplifier in a modern mobile communication system, in particular to a linearization method of a predistortion radio frequency amplifier. 【technical background】 [0002] For a long time, the efficiency improvement technology and the linearization technology of the power amplifier used in the communication system have been the research hotspots in the industry. [0003] Due to the adoption of various non-constant envelope modulation methods (such as QPSK, QAM, OFDM, etc.), modern wireless communication systems have greatly improved the utilization of frequency resources. , 2.5G, 3G, 4G, LTE) are growing rapidly, and the downlink in the system requires high-efficiency, high-linearity, multi-carrier power amplifiers to amplify to meet the needs of base stations (remote radio frequency unit RRU, repeater, indoor coverage system etc.) coverage requirements of the device. [0004] As...

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Problems solved by technology

[0005] Since the non-constant envelope signal of the modulation technology will cause the power amplifier to produce large nonlinear characteristics, the multi-carrier power amplifier conventionally adopts the feed-forward (FF) technology architecture, although it has excellent cancellation performance, wide operating bandwidth, and multi-standard However, due to factors such as high technical complexity, low efficiency, and high cost, its development is restricted

[0006] Due to the influence of factors such as narrow working bandwidth and poor cancellation effect, analog predistortion technologies such as envelope tracking cannot work in the case of multi-carrier

[0007] Digital predistortion technology is a promising linearization technology, which has the characteristics of high work efficiency and moderate cancellation, but due to the limitation of people's understanding of the nonlinear characteristics of semiconductor devices and the limitations of A / D, D / A. Due to the limitation of the working rate of DSP, the working bandwidth is limited, and its application is subject to certain restrictions.

In addition, no matter from a theoretical or practical point of view, domestic and foreign patent documents related to digital pre-distortion technology all reveal that the complexity of generating digital pre-distortion signals in the prior art is relatively high, and it cannot be adaptively adjusted to adapt to different electrical environments. Therefore, a good linearization technique effect cannot be achieved

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