IQ Imbalance Estimation and Compensation Schemes based on Time Frequency Interferometry for OFDM
IQ Imbalance Estimation and Compensation Schemes based on Time Frequency Interferometry for OFDM
复制标题
基于时频干涉的 OFDM IQ 不平衡估计和补偿方案
DOI：
10.1002/ett.2852
复制
发表时间：
2015
影响因子：
3.6
通讯作者：
and Ken-ya Hashimoto
中科院分区：
文献类型：
--
作者：
Hikaru Oka;Chang-Jun Ahn;Tatsuya Omori;and Ken-ya Hashimoto
直接转换接收器（DCR）可以降低功耗和成本。然而，采用正交频分复用 (OFDM) 的 DCR 会遇到 IQ 不平衡的问题。到目前为止，已经提出了许多算法来补偿 OFDM 系统中的 IQ 不平衡。然而，计算复杂度仍然是实现 DCR 的一项相当大的工作。此外，DCR还需要准确的信道识别。最近，时频干涉正交频分复用（TFI-OFDM）系统被提出，可以用少量导频符号实现精确的信道识别特性，并且具有导频幅度的周期性。在本文中，我们关注TFI的特点，并提出一种使用TFI-OFDM系统的新颖的IQ不平衡估计和补偿方案。在所提出的系统中，通过使用TFI导频符号的特征，我们可以识别IQ不平衡，而无需高计算复杂度。此外，通过使用子载波选择，可以降低噪声功率的影响。从仿真结果来看，所提出的方案可以在不降低误码率性能的情况下实现IQ不平衡估计和补偿的低复杂度。版权所有 © 2014 约翰·威利父子有限公司
A direct‐conversion receiver (DCR) can reduce the power consumption and cost. However, a DCR with orthogonal frequency‐division multiplex (OFDM) suffers from IQ imbalance. Until this time, many algorithms have been proposed to compensate IQ imbalance in OFDM systems. However, the calculation complexity is still a considerable work to achieve the implementation of a DCR. Moreover, an accurate channel identification is also necessary for a DCR. Recently, time‐frequency interferometry‐OFDM (TFI‐OFDM) system has been proposed to achieve an accurate channel identification property with small number of pilot symbols, and it has a periodicity of pilot amplitude. In this paper, we focus on the feature of TFI and propose a novel IQ imbalance estimation and compensation schemes using TFI‐OFDM system. In the proposed system, by using the feature of the TFI pilot symbols, we can identify an IQ imbalance without high calculation complexity. Furthermore, by using subcarrier selection, the influence of the noise power can be reduced. From the simulation results, the proposed scheme can achieve the low complexity for IQ imbalance estimation and compensation without a degradation of the bit error rate performance. Copyright © 2014 John Wiley & Sons, Ltd.