MIMO-OFDM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.本文从抑制符号定时同步存在偏差时的相关峰角度出发,提出采用交织的方法设计循环前缀,利用最大似然估计获得强相关峰已达到精确的符号定时同步,并分辨多径.该方法相对于传统的循环前缀添加方法只需要产生交织表,实现复杂度略有增加,但估计性能提高明显.%Accurate timing synchronization of symbol is important for MIMO-OFDM system, which can eliminate the integral frequency shift of cartier and intersymbol interference. But it is difficult to obtain the accurate timing because of complexity of MIMO wireless channel. To reduce the peak value of signals when error of timing exists, interleaved cyclic prefix and maximum likelihood estimation method are proposed, by which the correlational characteristic of that window is improved and the peak value is obtained only when the accurate timing presents for main path and multiple paths. In contrast with the traditional cyclic prefix, it is easier to obtain the accurate timing synchronization of symbol.
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