MIMO-OFDM水声通信关键技术研究

发布时间：2018-05-04 22:18

本文选题：多输入多输出 + 正交频分复用　；参考：《哈尔滨工程大学》2014年博士论文

【摘要】：多径干扰、低载波频率加之浅海水声环境的高背景噪声以及信道结构的时变特性,使得浅海水声信道成为迄今为止最困难的无线通信信道。此外,水声通信中可利用的带宽资源非常有限,通过提高发射功率以增加信道容量的方法已经接近饱和。因此,高频谱利用率的OFDM技术结合不需要增加可利用带宽或提高发射功率而能使信道容量获得本质提高的MIMO技术,成为近年来水声通信的新热点。本论文主要针对浅海水声通信中MIMO-OFDM的关键技术进行了研究,主要工作有:1 MIMO-OFDM水声通信中的发射分集和接收分集技术。分析了接收分集技术中合并技术在水声通信系统中的应用;研究了空时码技术在浅海水声中的应用,并通过仿真结果和试验结果进行比较,给出了多输入多输出系统分集算法的选择依据。2.MIMO-OFDM水声通信中的信道估计技术。比较分析了几种信道估计与补偿算法,并给出了选择具体算法的依据。在水声信道的条件下,对基于辅助导频的信道估计算法进行了仿真,并对不同导频间隔进行了性能分析。针对判决反馈信道均衡算法所存在的误码遗传缺陷,结合浅海水声信道的稀疏特性,提出了两种改进的信道估计与补偿技术。仿真和水池实验结果证实:两种改进的MMSE判决反馈追踪信道估计算法不仅可以有效的抑制误码遗传,对抗突发噪声,跟踪信道的缓慢时变,同时可以大幅度降低导频占用率,提高通信质量。3.MIMO-OFDM水声通信中的峰均比抑制技术。分析比较了不同种类的峰均比抑制算法。针对图样选择峰均比抑制算法需要额外传递图样选择信息的缺点,并结合浅海水声信道的稀疏特性,提出一种无需传送边带信息的图样选择峰均比抑制算法,并给出了三种具体的算法实现手段。仿真和实验结果表明,改进的无边带信息传输的图样选择峰均比抑制算法可以在不损失PAPR抑制性能的前提下,准确解算出传输图样,对抗突发噪声,实现无边带信息传输的可靠水声通信。
[Abstract]:Multipath interference, low carrier frequency and high background noise in shallow water acoustic environment, as well as the time-varying characteristics of channel structure, make shallow water acoustic channel the most difficult wireless communication channel so far. In addition, the bandwidth resources available in underwater acoustic communication are very limited, and the method of increasing channel capacity by increasing transmission power is nearly saturated. Therefore, OFDM technology with high spectral efficiency combined with MIMO technology, which does not need to increase the available bandwidth or increase the transmission power, has become a new hot spot in underwater acoustic communication in recent years. In this paper, the key technologies of MIMO-OFDM in shallow water acoustic communication are studied. The main work includes the transmit diversity and receive diversity in the 1: 1 MIMO-OFDM underwater acoustic communication. The application of combination technology in underwater acoustic communication system is analyzed, the application of space-time code technology in shallow water acoustic system is studied, and the simulation results are compared with the experimental results. The selection basis of diversity algorithm for multi-input and multi-output systems is presented. 2. The channel estimation technique in MIMO-OFDM underwater acoustic communication is presented. Several channel estimation and compensation algorithms are compared and analyzed. Under the condition of underwater acoustic channel, the channel estimation algorithm based on auxiliary pilot is simulated, and the performance of different pilot intervals is analyzed. Aiming at the error genetic defect of the decision feedback channel equalization algorithm and considering the sparse characteristics of shallow water acoustic channel, two improved channel estimation and compensation techniques are proposed. The results of simulation and tank experiments show that the two improved MMSE decision feedback tracking channel estimation algorithms can not only effectively suppress the error genetic, resist burst noise, and track channel slow time-varying, but also greatly reduce the pilot occupancy rate. Improve communication quality. 3. PAPR suppression technology in MIMO-OFDM underwater acoustic communication. Different PAPR suppression algorithms are analyzed and compared. In view of the disadvantage that the PAPR suppression algorithm of pattern selection requires extra transmission of pattern selection information, and considering the sparse characteristics of shallow water acoustic channel, a new PAPR suppression algorithm is proposed, which does not need to transmit sideband information. Three specific algorithms are given. The simulation and experimental results show that the improved peak-to-average ratio suppression algorithm can accurately solve the transmission pattern without losing the performance of PAPR suppression and resist the burst noise. The reliable underwater acoustic communication with no edge band information transmission is realized.
【学位授予单位】：哈尔滨工程大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN929.3

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