基于子空间的MIMO OFDM盲载波同步方法

针对MIMO OFDM系统,分析了多径信道与频域信号Hadamard积子空间的特点,构造了适合多天线条件下的基于子空间投影的频偏估计代价函数.该代价函数只和归一化频偏与接收数据有关,不需要信道信息和发送数据信息,因此是一种能有效提高数据传输效率的盲频偏估计方法.与已有盲同步方法相比,所提方法不需要使用虚子载波,因而频谱利用率可得到进一步提高.文中对算法的性能进行了仿真,验证了算法可对一个子载波间隔内的归一化频偏进行精确估计.结果表明,该方法性能优于已有文献提出的MIMO OFDM盲载波同步方法.

Blind Carrier Synchronization Method for MIMO OFDM System Based on Subspace

By analyzing the properties of Hadamard production subspace between the multipath channel and frequency domain signal of the MIMO OFDM system, the cost function of CFO (Carrier Frequency Offset) for the scene of multi antennas was given based on the subspace projection. No preliminary knowledge of the channels and the transmitter data are needed, so the method is one of the blind CFO estimation algorithms which can improve the transmitting efficiency of the system. Compared with the existing blind synchronization methods, the proposed algorithm does not need the virtual subcarriers, so that the available data bandwidth is higher furthermore. Simulation results confirm that it can estimate the normalized carrier frequency within a subcarrier space efficiently,and the superior performance of the proposed algorithm is achieved over the other available blind approaches for MIMO OFDM systems in the literature.