Digital Predistortion for Concurrent Dual-Band Transmitters Using 2-D Modified Memory Polynomials
Digital Predistortion for Concurrent Dual-Band Transmitters Using 2-D Modified Memory Polynomials
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DOI：
10.1109/tmtt.2012.2228216
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发表时间：
2013
影响因子：
4.3
通讯作者：
Youjiang Liu;Wen-hua Chen;Jie Zhou;Bang-Hua Zhou;F. Ghannouchi
中科院分区：
文献类型：
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作者：
Youjiang Liu;Wen-hua Chen;Jie Zhou;Bang-Hua Zhou;F. Ghannouchi
在并行双频发射机中的交叉带调制效应对于线性化是相当明显的。本文提出了一种新的二维修正记忆多项式（2D-MMP）技术来补偿并发双频发射机中的非线性失真。通过适当修改传统记忆多项式（MP）模型的包络项，考虑了跨带调制效应，建立了2D-MMP模型。这使得2D-MMP模型的模型复杂度与先前工作中的2D-DPD模型相比显著降低。然而，仍然保留了2D-MMP模型的线性化能力。仿真结果表明，2D-MMP模型对不同的PA模型具有很好的鲁棒性。实验测量进行了一个双波段AB类PA表现出轻度非线性和高度非线性双波段Doherty PA。结果表明，2D-MMP模型可以达到几乎相同的线性化精度相比，2D-DPD模型，与更少的系数。双频段AB类功率放大器（PA）的邻道功率比（ACPR）低于-52 dBc，双频段Doherty PA的邻道功率比（ACPR）低于-50 dBc。
Cross-band modulation effects in the concurrent dual-band transmitters are quite noticeable for the linearization. This paper proposes a novel two-dimensional modified memory polynomial (2D-MMP) technique to compensate for nonlinear distortion in the concurrent dual-band transmitters. By taking into account the cross-band modulation effects, the 2D-MMP model is developed by properly modifying the envelope terms of the conventional memory polynomial (MP) model. This makes the model complexity of the 2D-MMP model significantly reduced compared to the prior 2D-DPD model in previous work. However, the linearization ability of the 2D-MMP model is still retained. Simulations prove that the 2D-MMP model is quite robust to different PA models. Experimental measurements were carried out for a dual-band class-AB PA exhibiting mild nonlinearity and a highly nonlinear dual-band Doherty PA. The results show that the 2D-MMP model can achieve nearly the same linearization accuracy compared to the 2D-DPD model, with much less coefficients. Less than -52 dBc adjacent channel power ratios (ACPRs) for the dual-band class-AB power amplifiers (PAs) and -50 dBc ACPRs for the dual-band Doherty PA in the dual bands were achieved.