基于VTR-PLFM扩频调制的移动水声通信方法  

Mobile Underwater Acoustic Communication Method Based on VTR-PLFM Spread Spectrum Modulation

作　　者：季赵胜 王海燕[1] 申晓红[1] 李芾茏 JI Zhao-sheng;WANG Hai-yan;SHEN Xiao-hong;LI Fu-long(School of Marine Science and Technology,Northwestern Polytechnical University,Xi’an 710072,China)

机构地区：[1]西北工业大学航海学院,陕西西安710072

出　　处：《水下无人系统学报》2021年第4期391-399,共9页Journal of Unmanned Undersea Systems

基　　金：国家自然科学基金(61671386);国家重点研发计划(2016YFC1400204).

摘　　要：针对移动水声通信中多径效应、多普勒效应严重的问题,提出了基于虚拟时间反转-分段式线性调频(VTR-PLFM)扩频调制的移动水声通信方法,来同时对抗多普勒和多径干扰。首先利用分段式线性调频(PLFM)信号对发送信号进行正交扩频调制,因PLFM信号可以抗宽带多普勒频移,系统可以不进行多普勒频移补偿;同时利用虚拟时间反转(VTR)技术聚集多径信号的能量,削弱多径的影响,提升系统性能;此外,由于PLFM信号良好的相关性,进一步结合频分复用技术,可有效提升频谱的利用率,提高系统的通信速率。仿真验证了PLFM系统自身的抗多普勒频移特性及VTR技术的引入可有效改善系统性能,并且在较低信噪比和较高数据率下,PLFM系统有较低的误码率。外场试验验证了所提方法的可行性。Aimed at solving the serious problems of multipath effects and Doppler effect in mobile underwater acoustic communication,this study presents a mobile underwater acoustic communication method based on virtual time reversal-piecewise linear frequency modulation(VTR-PLFM)spread spectrum modulation,to resist both Doppler and multipath interference.Using the piecewise linear frequency modulation(PLFM)signal to perform orthogonal spread spectrum modulation,the PLFM signal can resist broadband Doppler frequency shift,but the PLFM system cannot perform Doppler frequency shift compensation;the virtual time reversal(VTR)technology can be used to gather the energy of multipath signals,weaken the influence of multipath,and improve the performance of the system.In addition,due to the good correlation of PLFM signals,frequency division multiplexing(FDM)can be introduced to improve the utilization rate of the spectrum and the communication rate of the system.The simulation results show that the anti-Doppler frequency shift and VTR technology can effectively improve the performance of the PLFM system.The resulting PLFM system has a lower bit error rate at a lower signal-to-noise ratio and a higher data rate.A field test is conducted to verify the feasibility of the proposed method.

关 键 词：移动水声通信 正交扩频调制 虚拟时间反转 频分复用 

分 类 号：TN929.3[电子电信—通信与信息系统] TN914.42[电子电信—信息与通信工程]