【作者】 张文博；

【导师】 周锋；

【作者基本信息】 哈尔滨工程大学 ， 水声工程， 2018， 硕士

【摘要】 由于人们对海洋开发越来越关注,为了能够方便的进行水下资源的探测与采集,水声技术也在日益进步。由于模拟调制技术容易受到噪声影响,在恶劣的水声信道中,无法很好的完成通信任务。因此,越来越多的水声技术采用数字器件。小型通信声纳系统采用数字OFDM通信方式,能够有效的对抗环境噪声。针对海洋牧场环境监测,高速数据传输等应用需求,设计并实现了一套基于TMS320C6748的OFDM小型通信声纳设备。能够实现海洋水文情况采集,实时无线水下通信等功能。首先按照本套系统的应用场景,对设备的整体参数进行设计,确定调制解调方式。接着针对OFDM解调方式容易受到频率偏移的影响,选取了三种多普勒补偿方式并进行比较。最终选取基于Chirp-z的多普勒补偿方式作为本系统的补偿方法。然后介绍了本套设备具体的电路设计,包括海洋水文数据采集、通信功能定时启动、OFDM信号发送与接收等功能。并在DSP上实现相应硬件的驱动编写,针对DSP串行指令的特点利用EDMA进行数据搬运,提高系统的运行速度。并在最后对DSP程序运行方式进行了改进,增强设备处理数据的速度。最后在实验室对各功能部分单独验证并完成整套设备的水文数据监测功能与通信功能检测。随后在信道水池展开测试,通过模拟海洋牧场的应用场景,验证设备的整体功能,保证使用需求。更多还原

【Abstract】 As people pay more and more attention to marine development.In order to facilitate the detection and collection of underwater resources,underwater acoustic technology also progressing.Because the analog modulation technology is easily affected by noise,communication tasks cannot be well performed in a poor underwater acoustic channel.Therefore,more and more underwater acoustic technologies use digital devices.The small communication sonar system adopts digital OFDM communication and can effectively counteract environmental noise.In this paper,aiming at the application needs of marine pastoral environment monitoring and high-speed data transmission.Design and implementation of a small-scale OFDM sonar device based on TMS320C6748.It can realize the collection of ocean hydrological conditions,real-time wireless underwater communication and other functions.First,according to the application scenario of the system,the overall parameters of the device are designed to determine the mode of modulation and demodulation.Then the OFDM demodulation method is easily affected by the frequency offset,and three kinds of Doppler compensation methods are selected and compared.Finally,the Doppler compensation method based on Chirp-z is selected as the compensation method for this system.Then introduced the specific circuit design of this set of equipment,including the collection of ocean hydrological data,timing start of communication function,OFDM signal sending and receiving functions.And on the DSP to achieve the corresponding hardware driver programming,for the characteristics of DSP serial instructions using EDMA data handling,improving the system’s operating speed.Finally,in the laboratory,each functional part is independently verified and completed the hydrological data monitoring function and communication function detection of the entire equipment.Subsequently,a test was conducted in the channel pool to verify the overall function of the equipment and to ensure the use of the requirements by simulating the application scenarios of the marine ranch.更多还原