Single Carrier Frequency Domain Equalization

Post date: Jun 13, 2015 7:10:24 PM

While minimum mean square error (MMSE) frequency domain equalizer (FDE) allows single carrier (SC) receivers to exploit the richness of the channel, the same equalizer does not provide gain for OFDM receivers since the DFT combines all paths incoherently and the impact of the multipath channel appears as a flat fading channel for each subcarrier. In OFDM, each subcarrier carries one symbol. In SC, each subcarrier carries information related to all symbols. Hence, when a subcarrier is faded due the channel, the symbol on that subcarrier is entirely lost in an uncoded OFDM scheme. However, only a portion of (all) symbols is lost for SC, which allows better BER results in high SNR regime for uncoded SC schemes [1]. The Matlab code that extracts the BER performance of MMSE-FDE for SC is attached.

[1] Fabriozi Pancaldi et al. “Single-Carrier Frequency Domain Equalization” IEEE Sig. Proc.Mag., Sep. 2008.