Mixed double-frequency digital pre-distortion model method based on DDR

Abstract

The invention provides a mixed double-frequency digital pre-distortion model method based on the DDR. The method includes the following steps that a concurrent double-frequency DPD system based on indirect learning is built; an operation sequence is optimized, a one-dimensional LUT achievement model of the 2D-MP is obtained, a one-dimensional LUT achievement model of 2D-MMP is derived, and then aone-dimensional LUT high-frequency concurrent double-frequency DPD achievement scheme and a model are provided; a dynamic deviation function is substituted into a one-order model of the DDR, and a discrete equivalent baseband expression of the one-order DDR model is obtained and extended to be in a synchronic double-frequency mode; a two-dimensional memory polynomial model same-order envelope cross term is introduced, and a new model and a one-dimensional LUT achievement method of the model in an FPGA are obtained. According to the method, the modeling accuracy and the linearization performance better than a simplified two-dimensional memory polynomial model and a traditional DDR model can be obtained; meanwhile, the advantage that achievement can be conveniently conducted through a one-dimensional lookup table is kept, the new model has a good level in the aspects of performance and complexity, and the method is suitable for practical system applying.

Description

technical field [0001] The invention relates to the field of digital pre-distortion of communication, in particular to a DDR-based hybrid dual-frequency digital pre-distortion model method. Background technique [0002] With the rapid evolution of mobile communication, modern wireless communication base stations should simultaneously support multiple standard communication systems to meet the diverse needs of users. The multi-frequency transmitter architecture has the advantages of low cost, small size, and high efficiency, and is the most promising multi-standard transmitter architecture. The multi-frequency power amplifier (PA) is a key module in the multi-frequency transmitter. In recent years, the efficiency enhancement and linearization methods for the multi-frequency PA have attracted extensive attention from scholars at home and abroad, especially the concurrent dual-frequency working mode. [0003] Under the simultaneous excitation of dual-frequency signals, the PA ...

AI Technical Summary

Problems solved by technology

In order to reduce the model complexity of 2D-MP, the modified 20-Modified Memory Polynomial model (20-Modified Memory Polynomial, 2D-MMP) has a more compact form and has a model complexity comparable to MP. However, 2D-MMP is about the The envelope coupling factor is nonlinear, and the identification of the envelope coupling factor has a high computational complexity

A simplified two-dimensional memory polynomial model (Simplified 2D-Memory Polynomial, DDR), DDR is easy to use one-dimensional LUT to implement, but because a large number of intermodulation cross terms are ignored in the model, the modeling accuracy deteriorates and the linearization performance is limited

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