Fractional Sampling OFDM/OQAM-IOTA on Multipath Channel with Long Delay Spread

Abstract

Orthogonal frequency division multiplex (OFDM) modulation systems can completely prevent intersymbol interference due to multipath propagation by providing a guard interval which is longer than the maximum delay spread. If the delay spread exceeds the guard interval, on the other hand, intersymbol interference (ISI) and intercarrier interference (ICI) occur. This paper evaluates the performance of a fractional sampling (FS) OFDM/Offset QAM-IOTA system in which FS achieves diversity. It is shown that FS OFDM/Offset QAM-IOTA system suffers less from ISI and ICI due to the delayed path even if the delay spread exceeds the guard interval.