An Efficient Blind Estimation of Carrier Frequency Offset in OFDM Systems
An Efficient Blind Estimation of Carrier Frequency Offset in OFDM Systems
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DOI：
10.1109/tvt.2013.2285479
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发表时间：
2014-05
影响因子：
6.8
通讯作者：
S. Lmai;A. Bourre;C. Laot;S. Houcke
中科院分区：
文献类型：
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作者：
S. Lmai;A. Bourre;C. Laot;S. Houcke
针对基于恒模（CM）信号的正交频分复用（OFDM）系统，提出了一种低复杂度的载波频偏盲估计方法。假设信道可以被假设为缓慢时变的，则在两个连续OFDM符号中具有相同索引的子载波将经历几乎相同的信道效应。这个假设使我们能够推导出成本函数，该成本函数由来自两个连续OFDM符号的每对等效子载波上的信号幅度的乘积之和确定。该成本函数的最大化过程使得找到CFO的适当估计成为可能。在频率选择性瑞利衰落信道中，所提出的CFO估计方法提供了优于现有技术的性能。此外，在窄带噪声和信号增益变化的情况下，仿真证明了我们的计划的鲁棒性和免疫力。
In this paper, we propose a low-complexity blind carrier frequency offset (CFO) estimation scheme for constant modulus (CM)-signaling-based orthogonal frequency-division multiplexing (OFDM) systems. Provided that the channel can be assumed to be slowly time-varying, subcarriers having the same indexes in two consecutive OFDM symbols will experience nearly the same channel effect. This assumption enables us to derive a cost function that is determined by the sum of the products of the signal amplitudes on each pair of equivalent subcarriers from two successive OFDM symbols. The maximization process of this cost function makes it possible to find an appropriate estimate of the CFO. Over frequency-selective Rayleigh fading channels, the proposed CFO estimation method provides improved performance over existing techniques. Moreover, in the context of narrow-band noise and signal gain variations, the simulations demonstrate the robustness and immunity of our scheme.