高速水声通信中的信道估计.doc
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高速水声通信中的信道估计,摘要随着海洋开发大战略的实施以及海上军事行动的实际需要，利用水下声信道进行信息传输的需求大大增加。由于海水中非均匀介质的吸收作用特别是对高频信号，使得水声通信中只能以声波作为唯一有效的载体信号，再加上水声信道较无线电信道更强的复杂性，导致了水声通信远远落后于陆地无线通信。水声通信的目的在于高速、可靠地将信源信息经过水声...
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摘 要
随着海洋开发大战略的实施以及海上军事行动的实际需要，利用水下声信道进行信息传输的需求大大增加。由于海水中非均匀介质的吸收作用特别是对高频信号，使得水声通信中只能以声波作为唯一有效的载体信号，再加上水声信道较无线电信道更强的复杂性，导致了水声通信远远落后于陆地无线通信。水声通信的目的在于高速、可靠地将信源信息经过水声信道传输到信宿。正交频分复用(OFDM)技术能够充分的利用水声信道的有限带宽，有效地抵抗多径传输所带来的码间串扰。同时它还可以与多输入多输出(MIMO)技术相结合，在保证原有性能指标的同时，进一步提高系统的信息传输速率，在水声通信中具有广阔的发展前景。但随着传输距离的增加，信道条件恶化，多径、多普勒频移影响加剧，需要采取有效手段进一步改善系统的性能。信道估计是其中的关键技术，直接影响水声通信传输系统的性能。本文以信道估计为出发点，研究了水声OFDM系统和水声MIMO-OFDM系统中的基于导频的信道估计算法，并结合水声通信特点设计一套立体式的水声数据传输通信网络。
本文对海洋水声信道的主要物理传输特性及其对水声通信的影响进行比较深入的分析，并在此基础上建立了水声信道模型。
对OFDM技术的基本原理以及关键技术进行深入分析，并由此得出其在水声高速通信中的技术优越性。在深刻理解OFDM技术的基础上，着重研究了水声OFDM系统中基于导频的信道估计技术的相关问题。结合块状导频的插入形式，对导频处的LS算法、MMSE算法和LMMSE算法进行了分析比较，通过理论及仿真分析得出了一些有用的结论。
对MIMO技术的基本原理以及关键技术进行了全面的分析，由此引出水声MIMO-OFDM通信系统。在上一章基础上，研究了水声MIMO-OFDM系统中基于导频的信道估计技术。探讨了信道估计中导频正交性的设计以及OFDM系统和MIMO-OFDM系统间导频信道估计的差异性。通过理论和仿真分析，验证了 MIMO-OFDM系统较OFDM系统有更好的性能表现。
对基于ZigBee技术的协议栈的工作流程、无线网络的建立、串口通信等进行了较深入的研究。结合水声通信信道特点，同时针对水声高速通信的应用需求，在陆上无线传感器网络和水声通信网络的基础上，建立了一套立体式的水声数据传输通信网络远程监控平台，其中包括硬件系统的设计和控制软件的设计。
关键词 水声通信；正交频分复用；多输入多输出；导频；信道估计
Abstract
With the development of ocean exploitation strategy and the needs for military operations on the sea, the needs for information transmission are greatly increased with the help of underwater acoustic (UWA) communication. But in UWA communication system, the acoustic wave is the only efficient method for long distance transmission, because of the absorption to the signal especially the high frequency signal in the sea, where there have different kinds of non uniform medium. What’s worse, because of the higher complexity in the underwater acoustic channel, the UWA communication is far behind the terrestrial wireless communication. The purpose of the UWA communication system lies in dependablely transmitting the signal form the source to the end through ocean acoustic channel at high speed. Orthogonal Frequency Division Multiplexing (OFDM) can takes full advantage of the limited bandwidth in UWA channel and effectively against inter-symbol interference which caused by multi-paths transmission. Meanwhile, it also can combines with Many Input Many Output (MIMO) technology, to further improve the system's information transmission rate which has a promising future in UWA communication. While longer the transmission range, worse the underwater with multi-paths and Doppler offset, which needs to take practical methods to improve the system. Channel estimation is one of the key technologies in communication transmission field. They directly affect the performance of the communication system. In this paper, we studied the channel estimation technology in underwater acoustic OFDM system and underwater acoustic MIMO-OFDM system, and then we designed a three dimensional underwater acoustic data communication network.
We analyzed the marine water channel’s transmission characteristics and its impact to the acoustic communication. And then we established the underwater acoustic channel model.
We deeply analyzed the basic principles of OFDM system and the key technology, which has a technical superiority in high-speed UWA communication. Next we mainly studied the channel estimation technology in underwater acoustic OFDM communication based on pilot. And then we analyzed and compared the performance of several algorithms based on block pilot, including algorithms of LS (Least-square), MMSE (Minimum Mean Square Error) and LMMSE (Linear Minimum Mean Square Error), so as to know the advantages and disadvantages among them. We can draw some useful conclusions through the simulation and theoretical analysis.
We completely analyzed the basic principles of MIMO system and the key technology in order to lead to the UWA MIMO-OFDM communication system. Then we mainly discussed and studied the channel estimation technology in MIMO-OFDM based on the studying discussed in OFDM system. We explored the designing of the orthogonality of pilot and contrasted the diversity between the two systems on channel estimation based on pilot. The simulation results show that the predominance in MIMO-OFDM system
We did a de..
随着海洋开发大战略的实施以及海上军事行动的实际需要，利用水下声信道进行信息传输的需求大大增加。由于海水中非均匀介质的吸收作用特别是对高频信号，使得水声通信中只能以声波作为唯一有效的载体信号，再加上水声信道较无线电信道更强的复杂性，导致了水声通信远远落后于陆地无线通信。水声通信的目的在于高速、可靠地将信源信息经过水声信道传输到信宿。正交频分复用(OFDM)技术能够充分的利用水声信道的有限带宽，有效地抵抗多径传输所带来的码间串扰。同时它还可以与多输入多输出(MIMO)技术相结合，在保证原有性能指标的同时，进一步提高系统的信息传输速率，在水声通信中具有广阔的发展前景。但随着传输距离的增加，信道条件恶化，多径、多普勒频移影响加剧，需要采取有效手段进一步改善系统的性能。信道估计是其中的关键技术，直接影响水声通信传输系统的性能。本文以信道估计为出发点，研究了水声OFDM系统和水声MIMO-OFDM系统中的基于导频的信道估计算法，并结合水声通信特点设计一套立体式的水声数据传输通信网络。
本文对海洋水声信道的主要物理传输特性及其对水声通信的影响进行比较深入的分析，并在此基础上建立了水声信道模型。
对OFDM技术的基本原理以及关键技术进行深入分析，并由此得出其在水声高速通信中的技术优越性。在深刻理解OFDM技术的基础上，着重研究了水声OFDM系统中基于导频的信道估计技术的相关问题。结合块状导频的插入形式，对导频处的LS算法、MMSE算法和LMMSE算法进行了分析比较，通过理论及仿真分析得出了一些有用的结论。
对MIMO技术的基本原理以及关键技术进行了全面的分析，由此引出水声MIMO-OFDM通信系统。在上一章基础上，研究了水声MIMO-OFDM系统中基于导频的信道估计技术。探讨了信道估计中导频正交性的设计以及OFDM系统和MIMO-OFDM系统间导频信道估计的差异性。通过理论和仿真分析，验证了 MIMO-OFDM系统较OFDM系统有更好的性能表现。
对基于ZigBee技术的协议栈的工作流程、无线网络的建立、串口通信等进行了较深入的研究。结合水声通信信道特点，同时针对水声高速通信的应用需求，在陆上无线传感器网络和水声通信网络的基础上，建立了一套立体式的水声数据传输通信网络远程监控平台，其中包括硬件系统的设计和控制软件的设计。
关键词 水声通信；正交频分复用；多输入多输出；导频；信道估计
Abstract
With the development of ocean exploitation strategy and the needs for military operations on the sea, the needs for information transmission are greatly increased with the help of underwater acoustic (UWA) communication. But in UWA communication system, the acoustic wave is the only efficient method for long distance transmission, because of the absorption to the signal especially the high frequency signal in the sea, where there have different kinds of non uniform medium. What’s worse, because of the higher complexity in the underwater acoustic channel, the UWA communication is far behind the terrestrial wireless communication. The purpose of the UWA communication system lies in dependablely transmitting the signal form the source to the end through ocean acoustic channel at high speed. Orthogonal Frequency Division Multiplexing (OFDM) can takes full advantage of the limited bandwidth in UWA channel and effectively against inter-symbol interference which caused by multi-paths transmission. Meanwhile, it also can combines with Many Input Many Output (MIMO) technology, to further improve the system's information transmission rate which has a promising future in UWA communication. While longer the transmission range, worse the underwater with multi-paths and Doppler offset, which needs to take practical methods to improve the system. Channel estimation is one of the key technologies in communication transmission field. They directly affect the performance of the communication system. In this paper, we studied the channel estimation technology in underwater acoustic OFDM system and underwater acoustic MIMO-OFDM system, and then we designed a three dimensional underwater acoustic data communication network.
We analyzed the marine water channel’s transmission characteristics and its impact to the acoustic communication. And then we established the underwater acoustic channel model.
We deeply analyzed the basic principles of OFDM system and the key technology, which has a technical superiority in high-speed UWA communication. Next we mainly studied the channel estimation technology in underwater acoustic OFDM communication based on pilot. And then we analyzed and compared the performance of several algorithms based on block pilot, including algorithms of LS (Least-square), MMSE (Minimum Mean Square Error) and LMMSE (Linear Minimum Mean Square Error), so as to know the advantages and disadvantages among them. We can draw some useful conclusions through the simulation and theoretical analysis.
We completely analyzed the basic principles of MIMO system and the key technology in order to lead to the UWA MIMO-OFDM communication system. Then we mainly discussed and studied the channel estimation technology in MIMO-OFDM based on the studying discussed in OFDM system. We explored the designing of the orthogonality of pilot and contrasted the diversity between the two systems on channel estimation based on pilot. The simulation results show that the predominance in MIMO-OFDM system
We did a de..
