Blind estimation of symbol timing and carrier frequency offset in wireless OFDM systems

Author

Bölcskei, Helmut

Author_Institution

Inf. Syst. Lab., Stanford Univ., CA, USA

Volume

49

Issue

6

fYear

2001

fDate

6/1/2001 12:00:00 AM

Firstpage

988

Lastpage

999

Abstract

Orthogonal frequency-division multiplexing (OFDM) systems are highly sensitive to synchronization errors. We introduce an algorithm for the blind estimation of symbol timing and carrier frequency offset in wireless OFDM systems. The proposed estimator is an extension of the Gini-Giannakis (see IEEE Trans. Commun., vol.46, p.400-411, 1998) estimator for single-carrier systems. It exploits the cyclostationarity of OFDM signals and relies on second-order statistics only. Our method can be applied to pulse shaping OFDM systems with arbitrary time-frequency guard regions, OFDM based on offset quadrature amplitude modulation, and biorthogonal frequency-division multiplexing systems. We furthermore propose the use of different subcarrier transmit powers (subcarrier weighting) and periodic transmitter precoding to achieve a carrier frequency acquisition range of the entire bandwidth of the OFDM signal, and a symbol timing acquisition range of arbitrary length. Finally, we provide simulation results demonstrating the performance of the new estimator

Keywords

OFDM modulation; frequency estimation; land mobile radio; pulse shaping; quadrature amplitude modulation; radio links; radio transmitters; statistical analysis; timing; Gini-Giannakis estimator; OFDM/OQAM; algorithm; bandwidth; biorthogonal frequency-division multiplexing; blind estimation; carrier frequency acquisition range; carrier frequency offset estimation; cyclostationary OFDM signals; downlink; estimator performance; mobile radio systems; offset quadrature amplitude modulation; orthogonal frequency-division multiplexing; periodic transmitter precoding; pulse shaping OFDM/QAM; second-order statistics; simulation results; subcarrier transmit power; subcarrier weighting; symbol timing acquisition range; symbol timing estimation; synchronization errors; time-frequency guard regions; wireless OFDM systems; Frequency division multiplexing; Frequency estimation; Frequency synchronization; OFDM; Pulse shaping methods; Quadrature amplitude modulation; Statistics; Time frequency analysis; Timing; Wireless sensor networks;

fLanguage

English

Journal_Title

Communications, IEEE Transactions on

Publisher

ieee

ISSN

0090-6778

Type

jour

DOI

10.1109/26.930629

Filename

930629