On Enhancing the Pilot-Aided Sampling Clock Offset Estimation of Mobile OFDM Systems

Keywords: OFDM, Sampling Clock Offset, Sampling Frequency Offset, Time-varying Channels, Doppler spread, ISDB-T system

Abstract

Sampling Clock Offset (SCO) estimation is an important issue in Orthogonal Frequency-Division Multiplexing (OFDM) systems because sampling frequency mismatch between the transmitter and the receiver may severely degrade the system performance due to the loss of orthogonality between the subcarriers.
SCO estimation in mobile environment is quite challenging since channel variation leads to an additional phase rotation that masks the SCO effects. However, most of the existing techniques rely on the assumption of a time-invariant channel and become considerably inaccurate in a mobile environment.
In this paper, we propose an improvement to an existing pilot-aided SCO estimator aiming to provide robustness against channel variations.
Performance was evaluated through simulations in an ISDB-T (Integrated Services Digital Broadcasting Terrestrial) compliant system and the results have shown a considerable improvement for all ranges of signal-to-noise ratios, specially for higher Doppler spread.

Author Biographies

Cássio Fraga Dantas, University of Campinas
Best graded student in Electrical Engineering Unicamp, class of 2014.
Davi Castro
Davi Castro was born in Maceió, Alagoas, Brazil in 1984. He obtained the degree of Electrical Engineer in 2009 from the Federal University of Campina Grande (UFCG), Brazil. He specialized in integrated circuit design through CI-Brasil training program in 2009. Since 2010 he has been working in R&D for telecommunication and digital TV semiconductor products at Idea! Electronic Systems.
Cristiano Magalhães Panazio, University of São Paulo
Cristiano Panazio  received a B.Sc. and an M.Sc. degree in electrical engineering from the State University of Campinas (UNICAMP), Brazil, in 1999 and 2001, respectively. He received his Ph.D. in 2005, also in electrical engineering, from the Conservatoire National des Arts Métiers (CNAM), Paris, France.   In 2006, he became Assistant Professor at Escola Politécnica of the University of São Paulo (EPUSP). He is member of the Brazilian Telecommunications Society (SBrT) since 1999. His research interests include equalization, multicarrier modulations, synchronization techniques and cognitive radio.
Published
04-06-2016
How to Cite
Dantas, C., Castro, D., & Panazio, C. (2016). On Enhancing the Pilot-Aided Sampling Clock Offset Estimation of Mobile OFDM Systems. Journal of Communication and Information Systems, 31(1). https://doi.org/10.14209/jcis.2016.10
Section
Regular Papers