Impact of Imperfect Channel Estimation on SC-FDE

Imperfect channel estimation can have a severe impact on the performance of coherent detection systems. In this paper we study the effect of imperfect channel knowledge in the performance of SC-FDE (Single Carrier with Frequency Domain Equalization). We propose a low complexity linear FDE which incorporates knowledge of the channel estimation error variance and derive analytical BER expressions. It is shown that its performance becomes more robust in the presence of strong channel estimation error components compared with a conventional FDE receiver. We also compare the degradation caused by imperfect channel estimation in SC-FDE and in OFDM schemes (Orthogonal Frequency Division Multiplexing) and show that the channel estimation requirements for SC-FDE are higher than for OFDM.