Joint Compensation of Transmitter and Receiver I/Q Imbalances for SC-FDE Systems
Joint Compensation of Transmitter and Receiver I/Q Imbalances for SC-FDE Systems
复制标题
SC-FDE 系统发射机和接收机 I/Q 不平衡的联合补偿
DOI：
10.1109/tvt.2020.2995848
复制
发表时间：
2020-08-01
影响因子：
6.8
通讯作者：
Li, Shaoqian
中科院分区：
文献类型：
--
作者：
Cheng, Xiantao;Yang, Ying;Li, Shaoqian
由于模拟元件的非理想性，发射机（TX）和接收机（RX）遭受诸如同相/正交（I/Q）不平衡的硬件损伤，其表现为I/Q分支之间的幅度、相位和频率响应的失配。如果没有补偿，I/Q不平衡会严重降低系统性能。研究了单载波频域均衡（SC-FDE）系统中TX和RX I/Q不平衡的联合补偿。具体来说，我们开发了一个期望最大化（EM）为基础的方法来分别估计TX和RX I/Q的不平衡，和多径信道。利用所得到的估计，我们可以很容易地实现I/Q不平衡的补偿。与以前的方法，它只估计的I/Q不平衡和多径信道的组合效果，我们能够获得TX I/Q不平衡，RX I/Q不平衡和多径信道的单独估计。长远来说，这将大大减轻拟议补偿计划的计算负担。仿真结果表明，该方案的性能优于同类方案，并能显著减轻I/Q不平衡的不利影响。
Due to the non-ideality of analog components, transmitters (TXs) and receivers (RXs) suffer from hardware impairments such as in-phase/quadrature (I/Q) imbalance, which manifests itself as the mismatches of amplitude, phase and frequency response between I/Q branches. Without compensation, I/Q imbalance can severely degrade the system performance. This paper addresses the joint compensation of TX and RX I/Q imbalances for single carrier frequency domain equalization (SC-FDE) systems. Specifically, we develop an expectation maximization (EM) based approach to separately estimate TX and RX I/Q imbalances, and the multipath channel. With the obtained estimates, we can readily fulfill the compensation of I/Q imbalances. Unlike previous methods, which only estimate the combined effect of I/Q imbalances and the multipath channel, we are able to obtain the separate estimates of the TX I/Q imbalance, the RX I/Q imbalance and the multipath channel. This will significantly alleviate the computation burden of the proposed compensation scheme in the long run. Simulation results show that the proposed scheme outperforms the counterparts, and can significantly mitigate the adverse effects of I/Q imbalances.