Optimal Pilot Sequence Design Based on Nonuniform Placement for MIMO OFDM Systems
基于非均匀分布的MIMO OFDM系统最优导频序列设计

In Orthogonal Frequency Division Multiplexing (OFDM) systems, to avoid influence of the low-pass filter on the transmitter side, some subcarriers on both edges of the allocated bandwidth are not used for transmission. These subcarriers are usually called virtual subcarriers which cause approach of conventional uniformly placed pilot tones inapplicable in some situations. Therefore, in this letter, based on nonuniform pilot tone placement, the optimal pilot sequences are derived, which can achieve the minimum mean square error of the least squares estimate for Multiple-Input Multiple-Output (MIMO) OFDM systems. Simulation results demonstrate the effectiveness of the proposed approach.