Enhanced carrier frequency offset estimation for OFDM using channel side information

Defeng Huang, Khaled Letaief

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

Carrier frequency offset (CFO) in OFDM systems, which induces the loss of orthogonality among OFDM sub-carriers, can result in significant performance degradation. As a result, it needs to be estimated and compensated for. In this paper, we present a general CFO estimator based on the maximum likelihood (ML) estimation criterion, with which CFO can be obtained using training OFDM symbols, pilot tones, null sub-carriers, or a combination of them. Using the proposed CFO estimator, the performance of CFO estimation can be significantly improved by taking advantage of the channel side information. In particular, using the channel statistics information, such performance improvement can be achieved for low SNR values and all SNR values over Rayleigh fading channels and Ricean fading channels, respectively. When the complete channel impulse response (CIR) information is available, simulation results will show that the performance improvement can be more than 6dB. To further demonstrate the capability of the proposed CFO estimator, we will consider an OFDM system using the signal structure of the IEEE WLAN standard 802.11 a. Compared with previous work using null sub-carriers alone, we will show that by taking advantage of the pilot tones, null sub-carriers, and channel statistics, the performance of CFO estimation can be improved by about 2dB.

Original languageEnglish
Article number1705940
Pages (from-to)2784-2792
Number of pages9
JournalIEEE Transactions on Wireless Communications
Volume5
Issue number10
DOIs
Publication statusPublished - Oct 2006
Externally publishedYes

    Fingerprint

Keywords

  • Carrier frequency offset
  • IEEE 802.11a
  • Null sub-carrier
  • OFDM

ASJC Scopus subject areas

  • Engineering(all)
  • Computer Networks and Communications

Cite this