A Study of Synchronization Techniques for an OFDM Underwater Communication System

• Main Authors: Han-Hsun Wu, 吳翰勳
• Other Authors: Ching-Hsiang Tseng
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/91244640116442653846

碩士 === 國立臺灣海洋大學 === 電機工程學系 === 101 === The orthogonal frequency division multiplexing (OFDM) is used in this thesis for underwater acoustic communication (UAC). The goodness of the designed OFDM UAC system is verified by computer simulation and actual water tank experiment. In the simulation, the OFDM baseband system is realized by using the LabVIEW software platform. A shallow water channel impulse response found in the literature is used as the channel. Considering the possible Doppler effect in a UAC channel, we also add subcarrier frequency offset to the simulation. The carrier frequency offset estimation and compensation is therefore a main focus of our research. In addition, we also conduct channel estimation and compensation in the simulation to see its performance. Both the cyclic prefix OFDM (CP-OFDM) and the zero padded OFDM (ZP-OFDM) and used in the simulation and the difference between the two is discussed. In the actual water tank experiment, an underwater acoustic transducer and a hydrophone are used in a water tank to transmit and receive the OFDM signal. The performance of the developed OFDM UAC system is evaluated through the experiment.