移动水声通信中的抗多普勒OCDM-《集美大学学报（自然科学版）》

文章信息/Info

Title:: Multiplex Resampling of OCDM Signals for Mobile Underwater Acoustic Communication

作者:: 朱培斌1; 冯磊1; 陈文1; 陈云飞1; 许肖梅2; 1.集美大学海洋信息工程学院，福建厦门 361021；2.厦门大学海洋与地球学院，福建厦门 361005

Author(s):: ZHU Peibin1; FENG Lei1; CHEN Wen1; CHEN Yunfei1; XU Xiaomei2; 1.School of Ocean Information Engineering,Jimei University,Xiamen 361021,China;2.College of Ocean and Earth Sciences,Xiamen University,Xiamen 361005,China

Keywords:: mobile underwater acoustic communication (UWA); orthogonal chirp division multiplexing (OCDM); time-varying Doppler shift; anti-Doppler

摘要:: 移动水声通信收发端之间不规则的相对运动，导致时变的多普勒频移，引起严重的ICI（inter-carrier interference），从而影响OCDM（orthogonal chirp division multiplexing）多载波水声通信的性能，而常规的重采样和残余载波频偏方法只能处理固定的多普勒频移。提出一种在OCDM通信中加入多路重采样用于处理时变多普勒频移的新方法。该方法根据所测得的多普勒标准差扩展了重采样范围，进而在移动水声通信中降低误码率；同时，在多路重采样中用可变分支数量降低计算复杂度，与固定分支数量相比，可节省约30％的计算成本。通过在移动水声通信中系统实现的抗多普勒OCDM，比较了千岛湖实测和水声信道仿真的多路重采样与单次重采样的BER（bit error rate）和FER（frame error ratio）性能，测试结果验证了该方案的可行性和抗时变多普勒的优越性。

Abstract:: Mobile underwater acoustic communication technology has been widely used in marine measurement and offshore engineering.The irregular relative motion between transmitter and receiver leads to time-varying Doppler shifts,which can cause severe inter-carrier interference (ICI) and thus affect the performance of orthogonal chirp division multiplexing (OCDM) communication.Conventional techniques such as resampling and residual carrier frequency offset can only handle constant Doppler frequency shift.This paper proposes a new method for handling time-varying Doppler shifts by adding multiplex resampling to OCDM communications.This method extends the resampling range based on the measured Doppler standard deviation and thus reduces the bit error rate (BER) in mobile underwater acoustic communications.Meanwhile,compared to using a fixed number of branches,using a variable number of branches in multiplex resampling lowers computational complexity and saves roughly 30% of the computational cost.It details the implementation and parameter selection of the Doppler-resistant OCDM in mobile underwater acoustic communication,and compare the performance of multiplex resampling and single resampling by simulation and actual measurement in Qiandao Lake.The proposed method’s viability and exellent anti-time-varying Doppler shift performance,are confirmed by the BER and frame error ratio (FER) results.