【作者】 吕丹丹； 杨士莪；

【Author】 L(U|¨) Dan-dan~1,YANG Shi-e~(1,2) (1.School of Navigation,Northwestern Polytechnical University,Xi’an 710072,China; 2.College of Underwater Acoustic Engineering,Harbin Engineering University,Harbin 150001,China)

【机构】 西北工业大学航海学院； 哈尔滨工程大学水声工程学院；

【摘要】 水声通信中的同步技术(帧同步,载波同步,定时同步以及相位同步等)是后续解调译码的前提,而帧同步是各种同步技术中首要的关键环节。本文基于正交频分复用(OFDM)多载波水声通信系统,研究了以线性调频信号(LFM)和带循环前缀的OFDM符号作为帧同步前导符号的两种帧同步体制的性能。通过计算机仿真,得出基于LFM信号体制在小信噪比时仍可有效工作,基于OFDM循环前缀体制在大信噪比下可用。进行了信道水池实验,得到结论:在信道水池条件下,两种同步体制都能有效地实现帧同步,都能使系统得到合理的吴码率。更多还原

【Abstract】 The synchronous technology,such as frame synchronization,carrier synchronization,timing synchronization and phase synchronization etc,is the premise of the subsequent demodulation and decoding,while frame synchronization is the primary key link in all sorts of synchronous technology.Based on the OFDM multicarrier underwater acoustic communication system,the performance of two typical frame synchronization methods,the Linear Frequency Modulation (LFM) signal and the preamble that consists of two identical OFDM symbols preceded by a cyclic prefix(CP),are studied. From the computer simulating,we obsreve that LFM based system can efficiently work,while the OFDM based approach can be taken used of only on large SNR condition.Finally,channel pool experiment results show that:in the channel pool conditions,both of the two frame synchronization techniques are able to realize the frame synchronization effectively,and the system can obtain a reasonable code error rate.更多还原