1. Department of Electrical and Electronic Engineering; Kyushu Institute of Technology; Kitakyushu 8048550 Japan
2. Institute of Oceanology; Chinese Academy of Sciences; Qingdao 266071 China
3. State Key Laboratory of Ocean Engineering; Shanghai Jiao Tong University; Shanghai 200240 China
4. School of Information Engineering; Yangzhou University; Yangzhou 225009 China
5. Department of Information Science and Electrical Engineering; Kyushu University; Fukuoka 8190395 Japan
6. Qualcomm R&D Center; San Diego 92121 USA
7. State Key Laboratory of Marine Geology; Tongji University; Shanghai 200092 China