【作者】 孙崇强；

【导师】 赵书俊；

【作者基本信息】 郑州大学 ， 核技术及应用， 2013， 硕士

【摘要】 OFDM技术是当今水声通信研究的热点技术,本文首先对OFDM基础技术进行了介绍,然后针对OFDM关键技术进行理论研究和相关实验。并在OFDM关键技术中提出了自己的理论方法,也给出了仿真及海试验证结果。本文所做的主要贡献如下：针对宽带水声通信遇到的多普勒效应问题,提出了一种利用多音频信号估计多普勒因子的新方法。根据水声信道的稀疏特性,提出了一种新的估计精度更高的稀疏信道估计方法。该方法通过在系统中插入少数导频,利用阶数递归的正交匹配追踪算法重构信道的非零系数,避免了直接对矩阵求逆,降低了计算复杂度,有利于工程实现。分析了水声信道遇到的问题,提出了采用OFDM技术的通信系统,并设计了相应的发射信号形式。对上述理论进行了仿真研究、海试验证。水声通信试验研究。针对OFDM系统的关键技术和整体性能,分别进行了水池试验和海上试验。数据处理结果充分验证了本文所提出的基于多音频信号的多普勒估计算法和阶数递归的正交匹配追踪算法的有效性和稳定性。试验结果表明,该系统能以较低发射声源级和误比特率,在浅海水域实现通信距离为3.7kmm、有效数据传输速率为187.5bps的数据传输。结合上述验证过的OFDM通信算法在论文的最后对当前水声通信研究的热点UUV互通通信进行了系统设计和通信方案设计,给出了详细的系统设计和理论推导过程,并开创性的采用PC104总线板卡,对大家研究UUV互通通信提供了可行性的参考方法。更多还原

【Abstract】 OFDM technology is the hot technology of underwater acoustic communication today. First introduced the OFDM-based technology,then do some theoretical and experimental about it. And put forward my own theoretical for OFDM key technology, approach also gives the results of the simulation and sea trial certificate. The main contribution of this paper made are as follows:On account of severe doppler effect existing in the wide band UWAC, a robust method for estimating the doppler shift by means of multi-tones signal is put forward; according to the sparsity property of the underwater acoustic channel impulse response, a novel channel estimating approach is given. An order recursive orthogonal matching pursuit algorithm is used to reconstruct the non-zero coefficients of the channel by inserting a small number of pilots in the system in the approach, to avoid the direct matrix inversion and reduce the computatial and engineering complexity. Analysis of the problems encountered in underwater acoustic channel communication system using OFDM technology, and design the corresponding forms of the transmitted signal. And then do simulation studiesand sea trial certificate about above theory.Study of UWAC experements. An pool trial and a sea experiment for key technologies and system performance of the OFDM system was organized respectively. The processing results of experimental data were proved that the validity and robust of the proposed Doppler estimation algorithm based on multi-tones signals and the OR-OMP algorithm. The results show that a effective information rate of187.5bps for the OFDM system was achieved with fairly lower transmited source level and BER performance.Combining the authentication OFDM communication algorithm, giving my own system design and communication design for underwater acoustic communication research focus, the UUV interworking communication, in the last. And groundbreaking use PC104bus board,and that will provide the feasibility reference for everyone who want to do UUV communication.更多还原