Joint estimation of I/Q imbalance, CFO and channel response for MIMO OFDM systems
Joint estimation of I/Q imbalance, CFO and channel response for MIMO OFDM systems
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DOI：
10.1109/tcomm.2010.05.080627
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发表时间：
2010-05
影响因子：
8.3
通讯作者：
Yuan-Hwui Chung;See-May Phoong
中科院分区：
文献类型：
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作者：
Yuan-Hwui Chung;See-May Phoong
本文研究了多输入多输出（MIMO）正交频分复用（OFDM）系统中基于训练序列的同相和正交相位（I/Q）不平衡、载波频偏（CFO）和信道响应的联合估计。提出了信道剩余能量的概念。我们表明，通过最小化CRE，我们可以联合估计的I/Q不平衡和CFO不知道的信道响应。该方法只需要一个OFDM块进行训练，训练符号可以是任意的。此外，当训练块由两个重复序列组成时，提出了一种低复杂度的两步法来解决联合估计问题。仿真结果表明，该方法的均方误差（MSE）接近Cramer-Rao界（CRB）。
In this paper, we study the joint estimation of inphase and quadrature-phase (I/Q) imbalance, carrier frequency offset (CFO), and channel response for multiple-input multipleoutput (MIMO) orthogonal frequency division multiplexing (OFDM) systems using training sequences. A new concept called channel residual energy (CRE) is introduced. We show that by minimizing the CRE, we can jointly estimate the I/Q imbalance and CFO without knowing the channel response. The proposed method needs only one OFDM block for training and the training symbols can be arbitrary. Moreover when the training block consists of two repeated sequences, a low complexity two-step approach is proposed to solve the joint estimation problem. Simulation results show that the mean-squared error (MSE) of the proposed method is close to the Cramer-Rao bound (CRB).