Frequency Offset Estimation Scheme in the Presence of Time-Varying DC Offset and IQ Imbalance for OFDM Direct Conversion Receivers
Frequency Offset Estimation Scheme in the Presence of Time-Varying DC Offset and IQ Imbalance for OFDM Direct Conversion Receivers
复制标题
DOI：
10.1109/pimrc.2007.4394308
复制
发表时间：
2007-12
期刊：
影响因子：
--
通讯作者：
M. Inamori;A. Bostamam;Y. Sanada;H. Minami
中科院分区：
文献类型：
--
作者：
M. Inamori;A. Bostamam;Y. Sanada;H. Minami
在WLAN系统中，已经实现了直接转换架构。虽然这种架构降低了成本和功耗，但它可能会受到DC偏移，频率偏移和IQ不平衡的影响。提出了一种OFDM直接变频接收机的频偏估计方法。本文提出了一种在时变直流偏移和IQ不平衡情况下的频偏估计方法。该方案的新奇在于其使用差分滤波器来减少DC偏移。评估所提出的估计方案进行了OFDM通信系统设计的IEEE 802.11a/g标准的无线局域网的规格。计算机仿真结果表明，该频偏估计方法在大直流偏移和IQ不平衡的情况下也能很好地估计频偏。
In WLAN systems, direct conversion architecture has been implemented. Though this architecture reduces the cost and power consumption, it may suffer from DC offset, frequency offset, and IQ imbalance. This paper presents a frequency offset estimation scheme for OFDM direct conversion receivers. In this paper, a frequency offset estimation scheme in the presence of time-varying DC offset and IQ imbalance is proposed. The novelty of this scheme is in its usage of a differential filter to reduce DC offset. Evaluation of the presented estimation scheme was carried out on an OFDM communication system designed to the specifications of the IEEE 802.11a/g standard for WLANs. Numerical results through computer simulation show that the proposed frequency offset estimation scheme works well even with large DC offset and IQ imbalance.