Block transmission techniques, with appropriate cyclic prefixes and employing FDE
techniques (Frequency-Domain Equalization), have been shown to be suitable for high data rate
transmission over severely time-dispersive channels. The most popular techniques based on this
concept are OFDM (Orthogonal Frequency Division Multiplexing) and SC-FDE (Single-Carrier
with Frequency-Domain Equalization).
In this paper we consider OFDM and SC-FDE transmission schemes and we study the impact
of the number of multipath components and the diversity order on their performance. It is shown
that when we have a high number of separable multipath components the asymptotic performance
of both schemes approaches the MFB (Matched Filter Bound), even without diversity. When we
have diversity the performance approaches the MFB faster, with a small number of separable
multipath components. It was also observed that the SC-FDE has a overall performance advantage
over the OFDM option, especially when employing the IB-DFE (Iterative Block Decision Feedback
Equalizer) with turbo equalization and for high code rates.