A Novel Subblock-Based Frequency-Domain Equalizer over Doubly-Selective Channels

A novel frequency-domain equalizer (FDE) is proposed for single-carrier block transmission over a doubly-selective channel. The proposed FDE partitions a received block into multiple subblocks in order to reduce the effect of the time variation of the channel. The nonuniformity in the error statistics of a subblock-based FDE is analyzed, when a one-tap minimum mean-squared error (MMSE) equalizer is employed. The nonuniformity is exploited to remove the drawback of subblock processing so that the performance of a subblock-based FDE is significantly improved. Numerical results show that the proposed FDE has much better performance than other known subblock-based FDEs. Furthermore, it has robust performance over high Doppler environments.