为了提高基于传统训练序列的定时同步精度和系统频谱的利用率,提出了MIMO-OFDM系统中一种特殊的同步训练序列并且给出了对应的定时和频偏估计方法.该方法利用构造倒序结构的同步训练序列获得比传统算法更精准的定时估计,同时该算法只需要一个训练序列就可以有效地对整数倍与小数倍频偏进行估计,与需要2个训练序列的传统算法相比,提出的算法减少了训练序列的数量,提高了系统频谱的利用率.仿真结果表明,在AWGN和改进的Jake模型信道环境下,所提出的方法在粗定时、精定时估计和载波频偏估计中都有很好的性能.
In order to improve both the accuracy of timing synchronization obtained by conventional methods and the utilization of the frequency spectrum, an efficient timing and frequency offset estimation method for multiple-input multiple-output- orthogonal frequency division multiplexing (MIMO-OFDM) systems was proposed. This algorithm includes a special training sequence to gain better symbol timing performance, and as a result, requires only one training symbol. This algorithm can efficiently estimate integer frequency offsets and fractional frequency offsets. Compared with conventional algorithms, the proposed method reduces the number of training symbols and improves the utilization of the frequency spectrum. Simulation results with additive white Gaussian noise (AWGN) and Jake's fading channel show that the method has good performance both in timing synchronization and carrier frequency offset estimation.