Implementation of an All-Digital Multi-Sensor Underwater Paging System Using TMS320C6x DSK

• Main Authors: Bin-Chong Wu, 吳鑌崇
• Other Authors: Fu-Sheng Lu
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/31414045905995262409

碩士 === 國立臺灣海洋大學 === 電機工程學系 === 93 === In this thesis, the Texas Instruments TMS320C6711 DSK module is used to build up an all-digital multi-sensor underwater paging system. The direct-sequence spread-spectrum techniques are investigated, and an all digital non-coherent delay-locked loop (DLL) for code synchronization is used in the synchronization. The underwater communication channel is a very complicated environment for data transmission. Due to the effect of the multipath, the synchronization is difficult to keep exactly. In order to improve the performance of the synchronization in the spread spectrum system, the diversity techniques are employed. Due to the severe multipath, the time delay of received signal will increase between the first path and the final path. The short PN sequence can not reduce the inter-symbol-interference (ISI) completely, and the decision directed decision feedback equalizer (DD-DFE) and BCH code are used to enhance the performance of the short PN sequence. The software design of system architecture is based on Matlab and C language. We also use a water tank to carry on the real-time communication experiment. The computer simulation and experimental results showed that the underwater paging system can restore the signal successfully with very low bit error rate.