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Improved Timing Synchronization Using Phase Difference between Subcarriers in OFDMA Uplink Systems  

Lee, Sung-Eun (Yonsei University)
Hong, Dae-Sik (Yonsei University)
Publication Information
Journal of the Institute of Electronics Engineers of Korea TC / v.46, no.2, 2009 , pp. 46-52 More about this Journal
Abstract
In this paper, the timing estimator based on the principle of the best linear unbiased estimator (BLUE) is proposed in OFDMA uplink systems. The proposed timing estimator exploits the phase information of the differential correlation between adjacent subcarriers. The differential correlation can extract the information about timing offset and mitigate the distortion of the signal caused by the frequency selectivity of channel. Compared with conventional methods, the proposed estimator shows more accurate capability in estimation. In addition, the estimator is hardly affected by the distortion caused by the frequency selectivity of channel. Simulation results confirm that the proposed estimator shows a small error mean and a relatively small error variance. In addition, the performance of the estimator is evaluated by means of SNR loss. It is shown by simulations that the SNR loss of the proposed estimator by estimation errors is less than 0.4 dB for the SNR values between 0 and 20 dB. This might indicate that the proposed estimator is suitable for the timing synchronization of multiple users in OFDMA uplink systems.
Keywords
OFDMA; Timing; Synchronization; Uplink; BLUE;
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