Robust Channel Estimation Scheme to the Intrinsic Interference of IOTA Function in OFDM/OQAM-IOTA System

OFDM/OQAM-IOTA system requires the IOTA (isotropic orthogonal transform algorithm) function that has superior localization property in the time and frequency domain instead of the guard interval used in conventional OFDM/QAM system to be robust to multi-path channel. However, conventional channel estimation scheme is not valid for the OFDM/OQAM-IOTA system due to the intrinsic inter-symbol interferences of the IOTA function. In this paper, we derive the condition to make the intrinsic interferences of the IOTA function zero based on the proposed pilot structure for the perfect channel estimation. We also derive the preamble structure appropriate to the practical channel estimation for the OFDM/OQAM-IOTA system, and the simulation results show that the OFDM/OQAM-IOTA system with the proposed preamble structure performs better than the conventional OFDM system with the additional advantage of the increased transmission rate as the amount of the guard interval.