Power Alignment of Digital Predistorters for Power Amplifiers Linearity Optimization
Power Alignment of Digital Predistorters for Power Amplifiers Linearity Optimization
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DOI：
10.1109/tbc.2008.2006652
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发表时间：
2009-01
影响因子：
4.5
通讯作者：
O. Hammi;F. Ghannouchi
中科院分区：
文献类型：
--
作者：
O. Hammi;F. Ghannouchi
本文研究了数字预失真器中的功率对准问题。通过调整用于合成预失真函数的归一化增益来实现适当的对准。研究了线性化放大器的线性度和功率效率与增益归一化因子的关系，结果表明线性化放大器的效率几乎不受归一化增益变化的影响。相反，线性化功率放大器的线性性能取决于增益归一化因子，这是通过预失真器的平均功率变化的结果。事实上，在适当选择归一化增益之后，预失真器的适当功率对齐显示了线性化放大器输出的测量的相邻通道功率比的显著改善。
In this paper, a study of the power alignment issue in digital predistorters is presented. The proper alignment is achieved by adjusting the normalization gain used to synthesize the predistortion function. The dependencies of the linearity and power efficiency of the linearized amplifier upon the gain normalization factor are investigated, and it is shown that the efficiency of the linearized amplifier is almost unaffected by variation of the normalization gain. Conversely, the linearity performance of the linearized power amplifier is found to be dependent on the gain normalization factor, as a consequence of the average power variation through the predistorter. Indeed, the proper power alignment of the predistorter following an adequate choice of the normalization gain shows a significant improvement in the measured adjacent channel power ratio at the linearized amplifier output.