Digital Predistortion for Concurrent Dual-Band Transmitters Using 2-D Modified Memory Polynomials

作者：Liu, You-Jiang^*; Chen, Wenhua; Zhou, Jie; Zhou, Bang-Hua; Ghannouchi, Fadhel M.

来源：IEEE Transactions on Microwave Theory and Techniques, 2013, 61(1): 281-290.

DOI：10.1109/TMTT.2012.2228216

• Cross-band modulation
• dual-band
• Doherty
• digital predistortion (DPD)
• memory polynomial (MP)
• power amplifiers (PAs)

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.

• 出版日期2013-1
• 单位中国工程物理研究院; 中国科学院电工研究所; 清华大学