A Class of Iterative FDE Techniques for Reduced-CP SC-Based Block Transmission

block transmission systems, the CP length is selected on the basis of the expected maximum delay spread. With regard to SC-based (Single Carrier) block transmission implementations, a full-length CP is recommendable, since it allows good performances through the use of simple FDE (Frequency-Domain Equalization) techniques. Recently, an algorithm for a ”Decision-Directed Correc-tion ” (DDC) of the FDE inputs, under reduced-CP condi-tions, was shown to provide good DDC-FDE performances, without significant error propagation, when using specially designed SC-based frame structures. In this paper, a low-complexity, SDDC-aided (Soft De-cision Directed Correction), iterative FDE technique is proposed for reduced-CP, SC-based block transmission systems using conventional frame structures. A more so-phisticated, SDDC-aided, Turbo FDE technique is also pro-posed to provide improved performances in such systems, through a moderately increased complexity. The relations with already known Turbo FDE and related iterative techniques, designed to operate under full-length CP, are established. A set of performance results concerning the proposed SDDC-aided techniques, with several complexity levels, as well as conventional iterative FDE techniques, is reported and discussed. The advantages of the SDDC-aided approach are emphasized, including the fact that it can operate in a satisfactory way even when, for the sake of implementation simplicity, no decoding operations are used to improve the iterative FDE process. I