A Low-Complexity Integer Frequency Offset Estimation Scheme Using Combined Training Symbols for OFDM Systems

 

Y. Lee¹, S. R. Lee², S. Yoo³, H. Liu⁴ and S. Yoon*⁵

 

¹ Samsung Electronics, Suwon, Korea.

² Department of Information and Electronics Engineering, Mokpo National University Muan, Korea.

³ Department of Electronics Engineering, Konkuk University Seoul, Korea.

⁴ School of Electrical Engineering and Computer Science, Oregon State University Corvallis, OR, USA.

⁵ College of Information and Communication Engineering, Sungkyunkwan University, Suwon, Korea. *syoon@skku.edu

 

Abstract

In orthogonal frequency division multiplexing (OFDM) systems, an integer part of a frequency offset (IFO) that causes ambiguity in data demodulation is estimated generally by comparing correlations between the received and local signals for IFO candidates. In this paper, we propose an IFO estimation scheme that provides a tradeoff between the estimation performance and the computational complexity including a conventional scheme as a special case. In the proposed scheme, template signals are formed by combining frequency-shifted training symbols, allowing the receiver to reduce the number of IFO candidates in the estimation process. Numerical results illustrate the tradeoff of the proposed scheme: The proposed scheme exhibits a tradeoff between the correct estimation probability and the computational complexity taking the number of the training symbols used to construct the template signal as a parameter.

Keywords: OFDM, integer frequency offset, tradeoff, training symbol.

 

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Aknowledgments

This research was supported by the National Research Foundation (NRF) of Korea under Grant 2014R1A5A1011478 and by the Convergence Information Technology Research Center (C-ITRC) support program supervised by the National IT Industry Promotion Agency (NIPA) under Grant NIPA-2014-H0401-14-1009 with funding from the Ministry of Science, ICT and Future Planning (MSIP), Korea, and by Priority Research Centers Program through the NRF of Korea under Grant 2009-0093828 with funding from the Ministry of Education, Science and Technology.

 

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