OFDM水声通信中基于SPM原理的载波频偏估计  

Accurate Doppler Factor Estimation with Signal Phase-Matching for OFDM System

作　　者：何成兵[1] 冉茂华[1] 黄建国[1] 陈志菲[1] 

机构地区：[1]西北工业大学航海学院,陕西西安710072

出　　处：《电声技术》2011年第1期56-59,共4页Audio Engineering

摘　　要：水声通信中由水声信道的时变性或本地振荡器失配所引起的载波频偏(CFO)非常普遍,这使得正交频分复用(OFDM)在高速通信中的应用面临严重挑战。因为CFO破坏了OFDM子载波间的正交性,产生严重的子载波间干扰(ICI),从而使得系统无法工作。针对这一问题,提出了一种基于信号相位匹配(SPM)原理的OFDM载波频偏估计方法,该方法较ESPRIT方法在低信噪比条件下能获得更好的估计精度且计算复杂度更低。基于典型水声信道条件的蒙特卡洛仿真证明了该方法的有效性。The major problem in applying OFDM to underwater channels is that it is vulnerable to carder frequency offset （CFO） caused by transceiver mismatch and/or Doppler shifts. And the loss of orthogonality due to the CFO effects must be compensated before the demodulation with discrete Fourier transform. A novel CFO estimation technique for OFDM communications is proposed over an underwater acoustic channel. The intrinsic structure information of OFDM signals is exploited to derive a CFO estimator based on signal- phase-matching （SPM） principle. Simulation results show that the main advantages of the proposed technique are computation simplicity and high accuracy.

关 键 词：水声通信 OFDM 相位匹配 载波频偏 

分 类 号：TN929.3[电子电信—通信与信息系统]