The advantages of a known sequence versus cyclic prefix in a SC/FDE system

In this work we investigate the advantages of a known symbol sequence - a so-called unique word (UW) - instead of the well-known cyclic prefix (as is used in OFDM systems) for a single carrier system with frequency domain equalization (SC/FDE). The concept of UW fulfills the theorem of cyclic convolution - required to implement an efficient equalization for the SC/FDE structure. We elaborate on the advantages that result for decision feedback equalization (DFE) in detail. It is shown that a DFE based on the concept of UW shows significant advantages in comparison to a traditional time domain DFE or a DFE based on cyclic prefix. Simulation results confirm the theoretical advantages.