摘要
多天线正交频分复用(MIMO-OFDM,Multiple-Input and Multiple-Output Orthogonal Frequency Division Multiplex)系统中,精确的符号定时同步可使接收端解调数据时消除载波频率偏移和符号间干扰。而由于MIMO空间信道复杂度较高,使得单天线OFDM系统的同步方法不能直接应用于MIMO-OFDM系统中。提出的两步同步方法首先利用时域导频作为第一步同步进行粗同步,然后利用循环交织前缀作为第二步同步对每一个MIMO-OFDM符号进行同步偏差调整。需要指出的是,两次同步过程均可以产生尖锐的相关峰,使得同步精度大为提高。
Accurate timing synchronization of symbol is important for MIMO-OFDM system,and it can eliminate the integral frequency shift of carrier and intersymbol interference.Two-step timing synchronization method is proposed in this thesis.First,the time-domain pilot is employed to obtain coarse timing synchronization,then the interleaved cyclic prefix and maximum likelihood estimation method are adopted to adjust the synchronization difference,through which the correlational characteristic of that window could be improved and the peak value obtained only when the accurate timing presents for main path and multiple paths.
出处
《通信技术》
2011年第7期54-56,共3页
Communications Technology
基金
"十一五"863计划重点项目(项目编号:20090AA011504)
国家重大专项"新一代宽带无线移动通信网"子课题(项目编号:2009ZX03003-008)
关键词
多天线
正交频分复用
导频
符号定时同步
最大似然估计
循环前缀
交织
MIMO
OFDM
pilot
timing synchronization of symbol
maximum likelihood estimation
cyclic prefix
interleaving.
