• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.2
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• pp.46-54
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• 2007

In this paper, we introduce the performance of improved symbol timing detection by the superposed difference type symbol timing detection method in the OFDM system. Also, we represent the maximum detection probability of symbol synchronization timing at each received delay signal in multipath channel delay profile in the correlation and difference type symbol timing detection methods. The computer simulation results show that the correlation symbol timing detection method have maximum detection probability at the lead of the nth received delay signal of highest amplitude, but the difference type symbol timing detection method always have maximum detection probability at the lead of the first received delay signal in the channel delay spread of $70nsec{\sim}217nsec$. The simulation results indicate the possibility of the perfect detection of OFDM symbol synchronization timing and it fit well with the results of improved S/N to the eb/n0 and the performance of symbol timing detection of the proposed method.

• Journal of Broadcast Engineering
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• v.16 no.1
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• pp.85-95
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• 2011

In this paper, we propose an alternative carrier phase independent timing recovery method for VSB receivers. The Gardner algorithm may not estimate a timing offset in VSB systems when the residual carrier phase offset is contained in the signal. We use the conjugate multiplication of received signals for cancelling out the carrier phase offset. Then Gardner algorithm is employed for extracting the spectral line. The proposed method generates a consistent timing error even in the presence of the carrier phase offset.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.10C
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• pp.1017-1026
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• 2005

In burst OFDM system, the frame synchronization should be performed first for the acquisition of received frame and the estimation of the correct FFT-window position. The conventional frame synchronization algorithms using design features of the preamble symbol, the repetition pattern of the OFDM symbol by pilot sub-carrier allocation rule and Cyclic Prefix(CP), has difficulty in the detection of precise frame timing because its correlation characteristics would increase and decrease gradually. Also, the algorithm based on the correlation between the reference signal and the received signal has performance degradation due to frequency offset. Therefore, we adopt a differential correlation method that is robust to frequency offset and has the clear peak value at the correct frame timing for frame synchronization. However, performance improvement is essential for differential correlation methods, since it usually shows multiple peak values due to the repetition pattern. In this paper, we propose an enhanced frame synchronization algorithm based on the differential correlation method that shows a clear single peak value by using differential correlation between samples of identical repeating pattern. We also introduce a normalization scheme which normalizes the result of differential correlation with signal power to reduce the frame timing error in the high speed mobile channel environments.