OFDM水声通信技术研究
文献类型：学位论文
| 作者 | 栾肇鹏 |
| 学位类别 | 博士 |
| 答辩日期 | 2009-05-26 |
| 授予单位 | 中国科学院声学研究所 |
| 授予地点 | 声学研究所 |
| 关键词 | 水声通信 正交频分复用 信道估计 |
| 其他题名 | Research on the OFDM Technology in Underwater Acoustic Communication |
| 学位专业 | 信号与信息处理 |
| 中文摘要 | 可用带宽窄、多途干扰强、信号起伏衰落严重是在水声信道特别是浅海水声信道进行高速可靠的信息传输的主要障碍。正交频分复用（OFDM）技术是近年来迅速发展起来的一种并行传输技术，将OFDM应用于水声通信是国内外研究的热点。OFDM具有良好的抗频率选择性衰落和频带利用率，使得它适用于水声信道。本文以实现OFDM在水声通信中的应用为出发点，研究了OFDM的关键技术，研制了OFDM水声通信系统原理样机，并进行了海试。仿真和海试的结果表明，系统可以在浅海环境下进行有效的通信。本文所作的主要工作包括以下几个方面： 1. 在研究OFDM基本原理的基础上设计了OFDM水声通信系统，给出了系统框图，并对同步、信道估计、降低峰均比等关键技术进行了仿真分析。 2. 研究了块状导频模式和梳状导频模式下的信道估计方法，在带有低通滤波的DFT变换域估计方法的基础上提出了一种改进方法，该方法通过自适应设定噪声滤除门限代替低通滤波，易于实现，经仿真验证性能良好。 3. 研制了OFDM水声通信原理样机，该样机的指标为：载波中心频率10KHz，带宽5KHz，有效数据率2.73kbps，使用QPSK符号映射，信道编码采用1/2卷积码和Turbo码。进行了一次海试，海试数据处理结果显示，该样机在水温条件不太好，信噪比大于7dB时，使用卷积码作为信道编码误码率低于10-4，使用Turbo码可以取得零误码，证明所设计的OFDM水声通信系统可以在浅海信道有效地进行信息传输。 |
| 英文摘要 | Narrow available band, strong multipath and severe fading are the main obstacles in high data rate, reliable communication in underwater acoustic channel, especially in shallow sea. The Orthogonal frequency division multiplexing (OFDM) has grown up rapidly in recent years. It is a hot topic that how to use OFDM in underwater acoustic (UWA) communication applications in these years. OFDM is robustness to frequency selective fading and bandwidth-efficient, which meet the demand of underwater acoustic channel. In order to use OFDM in UWA channel, the key technology of OFDM is studied, an underwater acoustic communication system based on OFDM is designed and simulated and a sea trial was taken. The results of simulation and sea trial prove that the system can work efficiently in shallow sea environment. Main work and achievements are summarized as follows: 1. An OFDM underwater acoustic communication system is designed based on the study of basic theories of OFDM. The key technologies such as synchronization, channel estimation, reduction of PAPR are simulated and analyzed. 2. The channel estimator using block-pilot-tones and comb-pilot-tones is studied. An improved method is proposed based on DFT-based estimator with low pass filter. The method replaces the low pass filter with setting a noise threshold self-adaptive. The proposed method is easy to be implemented. It has a good performance. 3. A prototype of OFDM acoustic communication scheme is proposed. The parameter is: carrier frequency 10KHz, bandwidth 5KHz, efficiency data rate 2.73kbps, QPSK symbol mapping. A sea trial was taken. The processing of sea trial result data proves that the OFDM system can perform well in shallow sea environment. |
| 语种 | 中文 |
| 公开日期 | 2011-05-07 |
| 页码 | 73 |
| 源URL | [http://159.226.59.140/handle/311008/554]  |
| 专题 | 声学研究所_声学所博硕士学位论文_1981-2009博硕士学位论文 |
| 推荐引用方式 GB/T 7714 | 栾肇鹏. OFDM水声通信技术研究[D]. 声学研究所. 中国科学院声学研究所. 2009. |
入库方式： OAI收割
来源：声学研究所
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