论文部分内容阅读
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。
Precise symbol timing synchronization allows the receiver to demodulate data to eliminate carrier frequency offset and intersymbol interference in MIMO-OFDM (Multiple-Input and Multiple-Output Orthogonal Frequency Division Multiplex) systems . However, due to the high complexity of the MIMO spatial channel, the synchronization method of the single-antenna OFDM system can not be directly applied to the MIMO-OFDM system. The proposed two-step synchronization method first uses the time-domain pilot as the first step to perform coarse synchronization and then uses the cyclic interleaving prefix as the second step to synchronize each MIMO-OFDM symbol for synchronization deviation adjustment. It should be pointed out that the two synchronization processes can produce sharp correlation peak, making the synchronization accuracy greatly improved.