An Adaptive Receiver Design for OFDM Systems Using Conjugate Transmission
An Adaptive Receiver Design for OFDM Systems Using Conjugate Transmission
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DOI：
10.1109/tcomm.2012.100512.110213
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发表时间：
2013-02
影响因子：
8.3
通讯作者：
Chin-Liang Wang;Po-Chung Shen;Ying-Chang Lin;Jia-Hong Huang
中科院分区：
文献类型：
--
作者：
Chin-Liang Wang;Po-Chung Shen;Ying-Chang Lin;Jia-Hong Huang
本文提出了一种在正交频分复用（OFDM）系统中有效消除载波间干扰（ICI）的自适应接收机。该接收机设计基于最近提出的相位旋转共轭抵消（PRCC）概念，其中在两个接收路径上采用两个单独的相位旋转，而不是在PRCC方案中针对两个发送路径仅采用一个相位旋转。我们使用最大化载干比的标准推导出最佳相位旋转，然后开发一种自适应归一化块最小均方算法来逼近最优解。利用接收机中的这种自适应相位旋转，可以有效地跟踪由于信道效应以及发射机和接收机处的振荡器之间的失配而引起的载波频率偏移（CFO）变化，而无需如PRCC中所要求的那样将CFO估计反馈给发射机。仿真结果表明，该方法具有更好的误比特率性能比PRCC和传统的CC方案的各种时变信道，即使在CFO/信道估计误差的考虑。
In this paper, we propose an adaptive receiver for efficient intercarrier interference (ICI) cancellation in orthogonal frequency division multiplexing (OFDM) systems using two-path conjugate transmission. This receiver design is based on the phase rotated conjugate cancellation (PRCC) concept presented recently, where two individual phase rotations are employed on the two receive paths, rather than only one phase rotation is adopted for the two transmit paths in the PRCC scheme. We derive the optimal phase rotations using the criterion of maximizing the carrier-to-interference ratio, and then develop an adaptive normalized block least mean-squared algorithm to approach the optimal solutions. With such adaptive phase rotations in the receiver, the carrier frequency offset (CFO) variations due to the channel effect and the mismatch between oscillators at the transmitter and receiver can effectively be tracked without feeding back the CFO estimate to the transmitter as required in PRCC. Simulation results demonstrate that the proposed approach has better bit error rate performance than the PRCC and the conventional CC scheme for various time-varying channels, even when the CFO/channel estimation error is considered.