Subblock processing in MMSE-FDE under fast fading environments

Abstract

Abstract-Frequency domain equalization (FDE) has been studied for reducing inter-symbol interference (ISI) caused by frequency selective fading in single carrier systems. When a high-mobility terminal exists in the system, the channel state may change within a DFT block. Then, the ISI reduction performance of FDE degrades since cyclicity of the channel matrix is lost. We propose to divide a 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 can effectively decrease the error floor in fast fading environments.Index Terms-Fast fading, single carrier transmission, MMSE-FDE, unique word, subblock processing

Optical Fiber Telecommunications VIB

“…In (11.84), H(ω) is given by (11.78) and S n (ω) is the power spectrum of the sampled noise. Throughput may be maximized using overlap-add or overlap-save convolution [165,166], while receiver complexity is minimized by inserting a cyclic prefix [167] or unique word [168][169][170] at the transmitter. Transmission of the cyclic prefix or unique word reduces throughput and wastes energy, but the unique word can be used as pilots to aid in timing, frequency, or phase synchronization.…”