Effects of Time Synchronization on OFDM Systems Over Time-Varying Channels

Author

Filippi, Alessio ; Husen, Sri Andari ; van Voorthuisen, P.

Author_Institution

Philips Res., Eindhoven

fYear

2006

fDate

11-14 Sept. 2006

Firstpage

1

Lastpage

5

Abstract

In this paper we refine a previously proposed model of time-varying OFDM systems, by taking into account the effects of non-ideal time synchronization. The considered non-ideal time synchronization includes the positioning of the receiver discrete Fourier transform (DFT) window and a cyclic shift of the input data. In OFDM systems with time-invariant channel, these two operations are equivalent. However, in the presence of a time-varying channel, OFDM suffers from intercarrier interference (ICI) which is differently affected by the positioning and the cyclic shift. We investigate the different effects and propose a refinement of the ICI modelling so that it holds also in the presence of non-ideal time synchronization. We verify the proposed refinement by testing a previously proposed ICI cancellation algorithm in the presence of non-ideal time synchronization

Keywords

OFDM modulation; discrete Fourier transforms; interference suppression; synchronisation; time-varying channels; OFDM systems; cyclic shift; discrete Fourier transform; intercarrier interference cancellation algorithm; nonideal time synchronization; time-invariant channel; time-varying channels; Channel estimation; Delay; Digital video broadcasting; Discrete Fourier transforms; Filters; Frequency synchronization; Intersymbol interference; OFDM; Robustness; Time-varying channels;

fLanguage

English

Publisher

ieee

Conference_Titel

Personal, Indoor and Mobile Radio Communications, 2006 IEEE 17th International Symposium on

Conference_Location

Helsinki

Print_ISBN

1-4244-0329-4

Electronic_ISBN

1-4244-0330-8

Type

conf

DOI

10.1109/PIMRC.2006.253955

Filename

4022632