新型船舶自动识别系统设计及其同步算法分析  

Design of a Novel Automatic Identification System and Analysis of Its Synchronization Algorithm

作　　者：马社祥[1] 刘兆杰[1] 

机构地区：[1]天津理工大学计算机与通信工程学院,天津300384

出　　处：《电讯技术》2017年第5期548-554,共7页Telecommunication Engineering

基　　金：国家自然科学基金资助项目(61371108;61601326);天津市高等学校科技发展基金计划项目(20140706;20140707);天津市应用基础与前沿技术研究计划(青年基金项目)(5JCQNJC01800)

摘　　要：为了提高船舶自动识别系统(AIS)的容量,提出了基于正交频分复用技术(OFDM)的新型AIS系统设计方案。新系统设计主要包括系统参数设计、系统帧结构设计。新系统链路容量和信道传输速率均较传统AIS系统提高了6倍,实现了频域资源的有效利用。该系统对符号定时偏差和载波频率偏差特别敏感,因此对接收信号的同步处理必不可少,在设计的新系统基础之上提出了一种新的盲估计算法,利用包含在循环前缀内的冗余信息,在多径信道信息未知的情况下,直接通过对接收信号做相关构造一个归一化的相关特性函数,通过此函数可得到符号时延位置和多径信道长度,进而得到载波频率偏差。仿真结果表明在多径信道下该算法也具有较好的性能。In order to improve the capacity of Automatic Identification System （AIS）,a novel AIS design scheme is presented in which Orthogonal Frequency Division Multiplexing（OFDM） is adopted as the signal modulation mode. The design of the novel system includes system parameter design and frame structure de-sign. The novel system makes full use of the spectrum resources and the l in k capacity and the transmission rate improve 6 times. OFDM system is particularly sensitive to the Symbol Timing Offset（ STO） and Carrier Frequency Offset（CFO）,soitis necessary to synchronize the received signal. A new blind symbol timing and frequency offset estimation algorithm is proposed which constructs a normalized correlation function be-tween the received signals in multi-path fading channels. The proposed method gets the timing offset and the channel length from the correlation characteristics of the function d irectly. Consequently,the frequency offset is jointly estimated. The simulation results show that the algorithm has better performance even in multi-path channel.

关 键 词：船舶自动识别系统 正交频分复用 符号定时偏差 载波频率偏差 同步 盲估计 

分 类 号：TN929.5[电子电信—通信与信息系统]