全相位FFT在合成孔径水声通信运动补偿中的应用  

Applications of All-phase FFT in Motion Compensation for Synthetic-aperture Underwater Acoustic Communication System

作　　者：王志杰[1] 李宇[1] 黄海宁[1] 

机构地区：[1]中国科学院声学研究所,北京100190

出　　处：《电子与信息学报》2013年第9期2206-2212,共7页Journal of Electronics & Information Technology

基　　金：国家863计划项目(2006AA09Z117;2009AA093601);国家自然科学基金项目(60672118;10904160)资助课题

摘　　要：该文针对浅海远程水声信道提出合成孔径技术与直接序列扩频相结合的通信方案,并重点分析了影响通信质量的多普勒效应问题,提出了一种有效的多普勒估计和补偿算法。该补偿算法采用重采样与全相位快速傅里叶变换(AP-FFT)处理技术,实现了频率和相位的高精度估计,同时消除多普勒造成的时间模糊。该文利用声学工具箱对声信道进行了建模,对合成孔径通信系统进行了仿真验证。结果表明,该文所提出的多普勒补偿算法有效地抵抗了收发节点以较高航速相对运动时所产生的多普勒效应,实现了多虚拟子阵发射信号的相干叠加,减少了运动造成的合成孔径处理空间增益损失,显著改善了通信质量。A communication scheme is proposed based on spread spectrum combined synthetic-aperture for long- rang acoustic communication in shallow water. The Doppler effect and an effective motion compensation method are analyzed using resampling technique combined with All-Phase FFT （AP-FFT） to perform the frequency and phase accuracy estimation, while eliminating the time fuzzy caused by Doppler. This paper uses the acoustic toolbox to model the acoustic channel for further synthetic-aperture communication simulation. The results show that the motion compensation approach proposed can effectively eliminate Doppler effect due to the relative movement between the two elements especially at a high speed. Consequently, this method achieves the coherent combination of signals transmitted by the virtual sub-arrays, reduces diversity gain loss and improves the communication quality significantly.

关 键 词：合成孔径水声通信 直接序列扩频 全相位FFT 运动补偿 

分 类 号：TN929.3[电子电信—通信与信息系统]