A Nonlinear Filter-Based Volterra Model With Low Complexity for Wideband Power Amplifiers
A Nonlinear Filter-Based Volterra Model With Low Complexity for Wideband Power Amplifiers
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DOI：
10.1109/lmwc.2013.2293657
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发表时间：
2014-01
影响因子：
3
通讯作者：
Jianfeng Zhai;Lei Zhang;Jianyi Zhou;Xiaowei Zhu;W. Hong
中科院分区：
文献类型：
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作者：
Jianfeng Zhai;Lei Zhang;Jianyi Zhou;Xiaowei Zhu;W. Hong
提出了一种基于非线性滤波器的低复杂度沃尔泰拉模型，用于宽带功率放大器的建模和特性分析。该模型具有类似于简化的基于二阶动态偏差减小（DDR）的沃尔泰拉模型的形式，但没有复杂的平方根计算和高阶项，其由一阶非线性滤波器代替。对于震级分布范围较小、存储和计算精度较低的模型参数，可以采用最小二乘法进行估计，从而使模型的复杂度低于二阶简化DDR沃尔泰拉模型。实验结果表明，该模型在宽带Doherty功率放大器中具有良好的性能和较低的复杂度。最后，利用该模型对Doherty功率放大器的非线性进行补偿，对100 MHz带宽的5载波高级长期演进（LTE-A）信号，邻道泄漏比（ACLR）改善超过12 dB。
A nonlinear filter-based Volterra model with low complexity is proposed for modeling and characterizing wideband power amplifiers. This model has a similar form of a simplified second-order dynamic deviation reduction (DDR)-based Volterra model but without complex square root calculations and high order terms, which are replaced by a first-order nonlinear filter. The model parameters with smaller magnitude distribution range and lower precision in storing and calculation can be estimated by least-square method, and then the model has lower complexity than the second-order simplified DDR Volterra model. Experimental results verified that good performance and lower complexity can be achieved by using this model for a wideband Doherty power amplifier. Finally, the model is employed to compensate the nonlinearity of the Doherty power amplifier, and over 12 dB adjacent channel leakage ratio (ACLR) improvement is achieved for a five-carrier long-term evolution advanced (LTE-A) signal of 100 MHz bandwidth.