短波低信噪比OFDM猝发通信系统同步算法  

Synchronization Algorithm for OFDM Burst Communication Systemat HF Low SNR Environments

作　　者：范慧丽[1,2] 孙景芳[2] 杨平[2] 

机构地区：[1]哈尔滨工程大学信息与通信工程学院,黑龙江哈尔滨150001 [2]武汉船舶通信研究所,湖北武汉430079

出　　处：《四川大学学报（工程科学版）》2011年第6期158-162,共5页Journal of Sichuan University (Engineering Science Edition)

基　　金：海装重点预研项目(1010306030101);船舶工业国防科技预研资助项目(3.7.3)

摘　　要：为解决低信噪比下短波正交频分复用(OFDM)系统信号的捕获,提出了一种采用CAZAC序列设计导频符号的基于谱分析的同步算法。首先通过时域、频域2维联合估计来实现信号的快速捕获,同时根据信号谱函数的最大峰值位置来确定整数频偏,然后利用相邻导频符号的相位差来精确估计小数频偏。最后,进行了算法仿真和现场可编程门阵列(FPGA)上的硬件实现及在线实时验证研究,结果表明,该同步方案在低信噪比条件下具有很好的同步性能,可以作为一个完整OFDM基带处理器的子模块实时、连续地对信号进行处理。Based on spectral analysis,a synchronization algorithm modulated multiple pilot symbols using Constant Amplitude Zero Auto-Correlation（CAZAC） sequence was presented for HF OFDM signal acquisition under low signal to noise ration.The fast signal acquisition was realized by time-frequency domain two-dimension estimation,and synchronously the integer frequency shift was obtained by the maximal peak position of spectrum function.Then the phase difference of adjacent pilot symbols was used for precisely fractional frequency shift estimation.Finally,Matlab simulations and on-chip real-time analysis of the algorithm using FPGA were done.The results demonstrated that this algorithm achieves fine performance at low SNR and can work efficiently as a block of an OFDM baseband receiver processor.

关 键 词：正交频分复用(OFDM) 同步捕获 现场可编程门阵列(FPGA) 低信噪比 

分 类 号：TN926[电子电信—通信与信息系统]