超宽带水声信道中基于空子载波内插的OFDM高精度多普勒系数估计技术研究

项目名称： 超宽带水声信道中基于空子载波内插的OFDM高精度多普勒系数估计技术研究

项目编号： No.61501061

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 无线电电子学、电信技术

项目作者： 陈阳

作者单位： 常州大学

项目金额： 19万元

中文摘要： 快速时变的超宽带水声信道中实现高效的多普勒系数高精度估计是高速水声OFDM移动通信的关键和难点之一，亟待解决。鉴于此，本课题发展OFDM空子载波内插技术，在此基础上提出一种快速时变环境下超宽带水声信道的OFDM通信高精度多普勒系数估计方法。为解决超宽带水声信道中非一致性多普勒频偏对OFDM多普勒系数估计造成的困难，按假设的多普勒系数计算空子载波的频率，进而利用不等间隔快速傅立叶变换获得所有空子载波的能量和。以空子载波能量和与假设多普勒系数之间存在的凹函数关系为代价函数，通过研究其解析表达，提出利用函数内插计算代价函数最小值位置来估计多普勒系数的方法。研究基于同步导频复用的多普勒系数粗测方法，为函数内插所需的采样提供基准，将OFDM空子载波内插技术应用到水声OFDM通信的多普勒系数估计中。本课题有望为实现水下移动平台间的高速数据传输提供技术支撑。

中文关键词： 水声重点项目群；水声信道；多普勒系数估计；水声通信；正交频分复用

英文摘要： Efficient Doppler scale estimation of high-precision is one of the most difficult key problems for underwater acoustic (UWA) OFDM mobile communication in fast time varying and ultrawideband (UWB) UWA channels, which is urgent to be solved. Hence, null subcarriers interpolation technology for UWA OFDM communication is proposed. And based on this technology a high-precision Doppler scale estimating method is developed, which is suitable for UWB UWA channels under fast time varying environment. To overcome the difficulty of achieving high-precision Doppler scale estimation due to the non-uniform Doppler shifts in UWA channels, the frequencies of null subcarriers are calculated according to expected Doppler scale and then the power of all null subcarriers by non-uniform fast Fourier transform (NUFFT). The concave function of the power of all null subcarriers and the expected Doppler scale is used as cost function, whose analytical expression is to be studied. Based on this, a Doppler estimation method by searching cost function’s minimum position through interpolation is proposed. Further more, Doppler scale rough estimating method is developed taking the use of synchronization and pilot reusing technology to provide the datum for function interpolation. High-precision Doppler scale estimation is achieved by applying this subcarriers interpolation technology in Underwater Acoustic OFDM Communication.The project provides a key support for high speed data transmission between underwater mobile platforms.

英文关键词： Key Project Group of Underwater Acoustic;Underwater Acoustic Channels;Doppler Scale Estimation;Underwater Acoustic Communication;OFDM