Low-complexity joint synchronization of symbol timing and carrier frequency for OFDM systems

• Published in: IEEE transactions on consumer electronics Vol. 51; no. 3; pp. 783 - 789
• Main Authors: Huarong Zheng, Huarong Zheng, Jue Tang, Jue Tang, Bo Shen, Bo Shen
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.08.2005; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Carrier frequencies; Channels; Correlation; Correlators; Error analysis; Estimation error; Frequency division multiplexing; Frequency estimation; Frequency synchronization; Hardware; Low pass filters; OFDM; Orthogonal Frequency Division Multiplexing; Symbols; Synchronism; Synchronization; Time measurements; Timing
• ISSN: 0098-3063; 1558-4127
• DOI: 10.1109/TCE.2005.1510484

Timing synchronization for guard-interval-based (GIB) orthogonal frequency multiplexing (OFDM) systems requires a correlator to correlate the last N/sub g/ (length of the guard interval) samples of the received OFDM symbol with their copies ahead. The straightforward implementation of this correlator results in the need to perform N/sub g/ complex additions for each correlator output. In this paper, we present an improved synchronization algorithm for the coarse joint estimation of symbol timing and carrier frequency offset. With the proposed algorithm, the coarse estimator can be implemented with extremely low hardware complexity by replacing the conventional correlator with a l-order low pass filter. Only one complex addition is needed for each output. The probability for frequency offset estimation error is analyzed for ideal channel. Simulation results show that it works reliably over both AWGN and multipath fading channels.