基于mesh结构的FHOFDM同步和信道估计算法  

Synchronization and Channel Estimation Algorithm for Mesh-based FH-OFDM System

作　　者：程永茂[1] 徐俊 曲晖[1] 

机构地区：[1]海军航空工程学院科研部 [2]91480部队司令部

出　　处：《控制工程》2013年第1期136-140,共5页Control Engineering of China

基　　金：国防科技预研基金项目(51307050302);海军航空工程学院青年科研基金资助项目(2010-0401)

摘　　要：针对海洋中无法设立传统基站对舰船通信进行辅助的问题,提出了mesh结构下的跳频正交频分复用系统。为了提高通信时的同步检测概率和系统误码性能,提出了快速有效的同步和信道估计算法。基于IEEE802.16d-2004标准,提出了改进的前导码结构。使用了GPS秒脉冲来修正的系统参考时钟,将时钟频率漂移由30 ppm降至0.01 ppm。给出了海面舰船移动通信时的频率时间双选择性衰落信道模型,并基于该模型提出了基于互相关函数和自相关函数联合判定的定时同步方法,通过峰值的判定可以将同步偏差控制在10个采样周期以内。使用了计算量较小的导频辅助线性插值信道估计算法,保证了接收节点能够快速的计算出有效的信道估计值。仿真结果表明所提出的定时同步和信道估计算法可以在60 km/h的移动速度下满足系统的定时同步和误码率要求。Mesh-based FH-OFDM system was designed to assist ship communication above sea without base-station. Efficient timing synchronization and channel estimation algorithm was presented to improve synchronization detection probability and BER performance. Improved preamble was presented based on IEEE802. 16d-2004. System reference clock was corrected by GPS, reducing clock error from 30ppm to O. 01 ppm. Mobile communication channel model was proposed for time frequency double selective fading channel above sea. By improved timing synchronization algorithm exploiting auto-correlation and cross-correlation function, timing offset was proved to be less than 10 sample period. Pilot-aided linear interpolated channel estimation algorithm was applied to get accurate estimation value. Simulation results show that new timing synchronization and channel estimation algorithm met the BER requirement of mesh-based FH- OFDM system under mobile environment of 60km/h.

关 键 词：跳频 正交频分复用 网格 定时同步 信道估计 

分 类 号：TP27[自动化与计算机技术—检测技术与自动化装置]