RA码在水声OFDM通信系统中的应用研究  

Applied research on RA codes in underwater acoustic OFDM communication system

作　　者：孙海信[1] 王菊香[1] 程恩[1] 苏为[1] 蒯小燕[1] 郭瑜晖[1] 徐小卡[2] 

机构地区：[1]厦门大学信息科学与技术学院,水声通信与海洋信息技术教育部重点实验室,福建厦门361005 [2]河南师范大学物理与电子工程学院,河南新乡453007

出　　处：《声学技术》2013年第2期136-140,共5页Technical Acoustics

基　　金：研究基金访问学者项目(2011631504);中央高校基础研究基金项目(201112G020和201212G012);国家自然科学基金项目(41176032)

摘　　要：正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)技术由于具有频谱利用率高、抗多径能力强等优点,成为当前水声通信的研究重点和热点,但较高的峰均功率比(Peak-to-Average Power Ratio,PAPR)严重影响了水声OFDM通信系统的性能。采用重复累积码(Repeat Accumulate,RA)作为信道编码方案,并用线性反馈移位寄存器(Linear Feedback Shift Registers,LFSR)代替原RA码结构中的累加器,再通过选择映射(Selective Mapping,SLM)方法降低系统的峰均功率比。计算机仿真和水池实验结果表明,采用改进结构的RA码结合SLM技术能有效降低水声OFDM系统的PAPR,提高系统的性能,具有很好的应用前景。Orthogonal frequency division multiplexing （OFDM） technology has become the research focus and hotspot of underwater acoustic communications owing to its advantages such as high spectrum efficiency and robustness to multipath fading, but it possesses high peak-to-average power ratio （PAPR） which severely degrades the performance of Underwater Acoustic OFDM Communication System. In this paper, repeat accumulate （RA） code is adopted as the channel coding scheme, and linear feedback shift registers （LFSR） is used to replace the accumulator of original RA code structure, then selective mapping （SLM） method is also adopted to reduce the PAPR of system. Computer simulation and experimental results show that modified RA code and SLM can effectively reduce the PAPR and improve the per- formance of underwater acoustic OFDM communication system, which have a very good application prospect.

关 键 词：OFDM RA码 峰均功率比 水声通信 

分 类 号：TN929.3[电子电信—通信与信息系统]