基于分数阶Fourier变换的正交多载波水声通信系统研究  

Research on orthogonal multi-carrier underwater acoustic communication system based on fractional Fourier transform

作　　者：王逸林 陈韵 殷敬伟 蔡平 张艺朦 

机构地区：[1]哈尔滨工程大学水声技术重点实验室,黑龙江哈尔滨150001

出　　处：《通信学报》2012年第8期162-170,共9页Journal on Communications

基　　金：哈尔滨工程大学水声技术重点实验室基金资助项目(9140C200802110C20);国家自然科学基金资助项目(51179034;60802060);教育部高等学校博士点基金资助项目(200802171061);上海交通大学海洋工程国家重点实验室开放课题基金资助项目(1007)~~

摘　　要：针对传统OFDM系统在应对深度频率选择性衰落信道时性能下降和多普勒频偏造成子载波相互干扰的问题,提出采用正交的线性调频(LFM)信号作为载波,基于分数阶Fourier变换(FRFT)的正交多载波水声通信方案。该方案选用相同调频斜率,不同中心频率,频带相互重叠的正交LFM作为子载波进行信息调制,以分数阶Fourier变换作为调制解调方法来传输信息。为应对水声信道的多途效应,采用在数据帧与帧之间插入保护间隔(GI)来减小码间干扰。提出结合QDPSK和分数阶域载波位置修正抑制多普勒效应,简化系统复杂度。该方案最高通信速率可达3.6kbit/s,通过仿真研究和湖试实验验证了该方案的有效性与可行性。Aimed at the traditional OFDM communication system falls when the channel was frequency-selective, rapidly fading and had the Doppler effects, resulting in inter-cartier interference, a orthogonal multi-carrier system for underwater acoustic communication was proposed, which employed orthogonal signal basis of the chirp type corresponding to the fractional Fourier transform （FRFF） signal basis. The scheme used the orthogonal LFM signal as sub-carrier to modulate, which had same chirp rate but different center frequency with overlapped bandwidth, and used fractional Fourier transform for modulation and demodulation method to transmit information. For suppression of the multi-paths channel effect, the guard interval （GI） was used between signal data frame. And the position correction in fractional do- main method combining with QDPSK was proposed to suppress the Doppler effects, which simplified the system com- plexity. The communication scheme had the characteristic of high communication rate, and the maximum rate was up to 3 600bit/s. The effectiveness and reliability of this system was verified through a large number of simulation and lake ex- periments.

关 键 词：水声通信 分数阶FOURIER变换 正交多载波 多普勒效应 

分 类 号：TB567[交通运输工程—水声工程]