Low Complexity Blind Carrier Frequency Offset Estimation for MIMO-OFDM Systems

A novel closed-form subspace-based blind CFO estimation approach for MIMO-OFDM systems is proposed. Our key observation is that the CFO information is redundant in spectrum structure. By allocating null carriers equispaced at the transmitter and downsampling and collecting the received blocks from all antennas at the receiver, the dimension of parameter space is greatly reduced compared with previous proposed subspace- based methods. Consequently, a lower computational complexity approach is obtained. Furthermore, estimation performance is also improved significantly. Analysis and simulation results demonstrate the effectiveness of our proposed method.