用于多比特正交发射机的基于图形转换的全自动预失真技术

多比特正交架构是全数字发射机方案中最有前景的一种,但因为存在着显著的非线性,而需要复杂的二维预失真,并且前人提出的迭代测量法建立预失真表时间长约1ms.本文提出了图样转换的方案来解决预失真表建立时间过长的问题.本文方案将预失真表的建立时间缩短到20μs之内,同时对7.2dB PAPR和40MHz带宽的长期演进(Long Term Evolation,LTE)信号,布局前仿真中预失真后信号带内误差能减少到-30.07dB.本文方案不仅节省了预失真过程的时间和功耗,也使多比特正交发射机预失真表的实时建立首次成为可能.

Fully Automatic Predistortion Based on Profile Inversion for Multi-bit Cartesian Transmitters

The multi-bit Cartesian scenario,one of the most promising scenarios among the all-digital diversity of the transmitters,exhibits significant nonlinearity and requires complex 2D predistortion.As a partial solution to building the predistortion coefficients,iterative measurement has been proposed,but it is imperfect with respect to its lengthy procedure which takes around 1 ms.We propose a novel scheme of profile inversion to tackle the problems.Compared to iterative measurement,our scheme greatly reduces the setup time in the predistortion coefficients to less than 20 μs,while achieving predistorted in-band error of-30.07 dB with an LTE signal with 7.2 dB PAPR in pre-layout simulation.Not only does the present scheme save the time and power consumption in the predistortion process,but also it renders a real-time predistortion setup for multi-bit Cartesian transmitters practicable for the first time.