水声通信实验系统设计

发布时间：2018-03-29 01:28

本文选题：水声通信　切入点：OFDM　出处：《华南理工大学》2014年硕士论文

【摘要】：水声信道的频带极其有限和多径干扰十分严重是目前制约水声通信数据率提高的主要瓶颈。正交频分复用（OFDM）技术具有抗多径干扰和频谱利用率高等特性被大量通信标准所采用，是目前实现高速水声通信的常用技术。现有的通信系统一般存在硬件较复杂，成本较高，且不利于升级和更新等问题，软件无线电的出现，大大简化了系统的硬件结构，系统工作频率、系统带宽、调制方式、信源编码等可进行编程控制，使得系统灵活性显著增强，节省成本且便于升级。结合OFDM和软件无线电两种技术的优势，本文设计了一种基于软件无线电技术的高速水声通信系统。论文详细描述了系统框架、软硬件设计和信号处理流程。其中，硬件部分主要由信号发生卡、功放电路、水声换能器、信号采集卡和计算机组成。论文根据系统要求设计了功率放大电路，，阐述了功放各部分的原理和结构。系统的软件设计是本文的重点，软件系统采用多线程并行运行架构，信号的采集和发生，信号的调制与解调，系统主控程序等模块分别采用不同线程，论文对这些模块进行了详细设计与实现。最后，经过多次基于不同环境的水声实验，验证了该系统具有可靠的传输性能，系统传输速率可达到6.3kbps-10kps。本文对各种实验数据进行了分析，得到了在不同环境和传输距离下的信道特性。本系统在远距离传输中表现的性能不够理想，误码较高，因此如何改善数据处理的过程并优化算法，是下一步要研究的方向。
[Abstract]:The limited frequency band and serious multipath interference of underwater acoustic channel are the main bottlenecks to improve the data rate of underwater acoustic communication at present. Orthogonal Frequency Division Multiplexing (OFDM) technology has the characteristics of anti-multipath interference and high spectral efficiency, which are adopted by a large number of communication standards. It is a common technology to realize high speed underwater acoustic communication at present. The existing communication systems generally have some problems such as complex hardware, high cost, and not conducive to upgrading and updating. The appearance of software radio greatly simplifies the hardware structure of the system. The system operating frequency, system bandwidth, modulation mode, source coding and so on can be programmatically controlled, which makes the system flexible, cost saving and easy to upgrade. Combining the advantages of OFDM and software radio, a high speed underwater acoustic communication system based on software radio technology is designed in this paper. The system framework, software and hardware design and signal processing flow are described in detail. The hardware is mainly composed of signal generator card, power amplifier circuit, underwater acoustic transducer, signal acquisition card and computer. The principle and structure of various parts of power amplifier are expounded. The software design of the system is the focus of this paper. The software system adopts multi-thread parallel running architecture, signal acquisition and generation, signal modulation and demodulation. The main control program of the system adopts different threads, and these modules are designed and implemented in detail. Finally, after many underwater acoustic experiments based on different environments, it is proved that the system has reliable transmission performance, and the transmission rate of the system can reach 6.3 kbps-10kps.All kinds of experimental data are analyzed in this paper. The channel characteristics in different environments and transmission distances are obtained. The performance of the system in long-distance transmission is not ideal and the error code is high. Therefore, how to improve the process of data processing and optimize the algorithm is the next research direction.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.3

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