Subblock Processing for MMSE-FDE Under Fast Fading Environments

Frequency domain equalization (FDE) has been studied for suppressing inter-symbol interference (ISI) caused by frequency selective fading in single carrier systems. When a high-mobility terminal exists in the system, channel state changes within a DFT block. Then, the ISI reduction performance of FDE degrades since cyclicity of the channel matrix is lost. Here, we propose to divide received data block into multiple subblocks to decrease the channel transition within the DFT block in fast fading environments. Also, to satisfy periodicity of the received signal in each subblock, we introduce a pseudo cyclic prefix technique. The results of numerical analysis show that the proposed method provides 1.3-fold increase in tolerable Doppler frequency for FER of 0.01.