• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.05a
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• pp.336-340
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• 2003

The frame synchronization should be acquired before performing other data-aided receiving algorithms, such as data-aided channel equalizing, beam-forming and phase, symbol timing, and frequency synchronizing, since all of them are using preamble or training sequence to estimate the amount of error from the received signal. In this paper, we present a new frame synchronization scheme for underwater ultrasonic image burst transmission system, which computes the correlation between received symbol sequence and one CAZAC sequence, composed of the latter half of the first CAZAC sequence of preamble and the first half of the second CAZAC sequence of preamble and then compares a threshold value. If the correlation value is bigger than the threshold value, the frame detector determines that the frame synchronization is achieved at that sample.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.10
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• pp.43-48
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• 2010

In general, in order to reduce an initial cell searching time, W-CDMA systems adopt a three-step cell search scheme: slot synchronization, frame synchronization, and primary scrambling code identification. We consider the second step (frame synchronization), in which a coherent detection using P-SCH (primary synchronization channel) is possible. In this paper, we propose a new coherent detection scheme, where a first order recursive filter is used to enhance channel estimation performance. Computer simulation results indicate that the detection performance of the proposed scheme can be robust over large range of frequency offset.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.3
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• pp.687-694
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• 1999

In this paper, to draw out the parameter of synchronization for ADSL(Asymmetric Digital Subscriber Line) chip design, we analyze the performance of STR(Symbol Timing Recovery) and frame synchronization with computer simulation. We analyze and design PLL(Phase Lock Loop) loop for ADSL. As a result, we obtained the optimum parameter of STR to design ADSL chip. Also, when performed frame synchronization with several algorithm, we analyzed the performance of FER(Frame Error Rate) and the effect of frame offset with computer simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.1A
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• pp.73-81
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• 2012

In this paper, we propose a high-speed synchronization method for Digital Radio Mondiale (DRM) receivers. In order to satisfy the high-speed synchronization requirement of DRM receivers, the proposed method eliminate the initial sampling frequency synchronization process in conventional synchronization methods. In the proposed method, sampling frequency tracking is performed after integer frequency synchronization and frame synchronization. Different correlation algorithms are applied to detect the first frame of the Orthogonal Frequency Division Multiplexing (OFDM) demodulation symbol with sampling frequency offset (SFO). A frame detection algorithm that is robust to SFO is selected based on the performance analysis and simulation. Simulation results show that the proposed method reduces the time spent for initial sampling frequency synchronization even if SFO is present in the DRM signal. In addition, it is verify that inter-cell differential correlation used between reference cells is roubst to the effect of initial SFO.

• The Journal of the Acoustical Society of Korea
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• v.41 no.2
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• pp.159-165
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• 2022

In this paper, a frame synchronization structure for the Binary Phase Shift Keying (BPSK) modulation method in underwater acoustic communication was proposed. The proposed frame synchronization structure is largely divided into two. First, the approximate position and frequency offset of the frame are obtained by non-coherent correlation and sliding Fast Fourier Transform (FFT) method. Second, after compensating for the frequency error to the received signal, the exact position of the frame is obtained by coherent correlation method. Maritime experiments were conducted to confirm the performance of the 2-STEP frame synchronization structure. It was showed that the limitations of the non-coherent correlation and sliding FFT method can be verified when the power of the received signal was greatly reduced due to the channel characteristics. As a result, stable frame synchronization could be obtained by compensating for the frequency error and then using the coherent correlation method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.7A
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• pp.552-559
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• 2012

In this paper, we introduce a frame structure of the satellite TDMA network and the synchronization method thereof. The primary station transmits a special burst called reference burst which provides reference time to network. By using this reference burst all nodes achieve initial acquisition and synchronization. We consider time drift due to the node and satellite mobility, time shift due to the node position, Doppler shift due to the node mobility and frequency offsets as important factors of the frame structure. Simulation results show that the proposed frame structure and synchronization method guarantee accurate synchronization performance when the node is even in low SNR as well as 25 kHz frequency offsets.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.187-190
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• 1998

In this paper, a synchronization method of OFDM signals are introduced and its performance is estimated. A proposed method can perform a frame/symbol timing, carrier frequency synchronizations. Reference symbols consist of two duplicate OFDM symbols carrying signals on every sub-carriers. Performances of synchronization under 60GHz millimeter-wave indoor channels are evaluated, which were measured with frequency-sweeping method in common office buildings. A proposed method has improved performances owing to long averaging durations of synchronization metrics in frame/symbol timing, carrier frequency synchronization procedures.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.5
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• pp.643-649
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• 1993

The problem of locating a periodically inserted frame synchronization pattern in random data for a binary pulse amplitude modulated (PAM) digital communication system over a additive white Gaussian noise(AWGN) channel with co-channel interference is considered. The performance degradation of frame synchronization for the correlation rule due to the presence of co-channel interference is shown. The maximum likelihood(ML) decision rule for the frame synchronization over an AWGN channel with co-channel interference is derived. For the entire range of SNR considered, the ML frame synchronization rule obtains about 1dB signal energy gain over the correlation rule. Specially, the ML rule obtains as much as 2dB gain over the correlation rule when the SNR is greater than 0dB.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.195-196
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• 2006

Frame synchronization is an critical factor for an effective operation of OFDM (orthogonal frequency division multiplexing) based communication systems. In this paper, we present and analyze an efficient frame synchronization method based on m-sequence for OFDM-based mobile multimedia communication systems. The cyclic extension preceding OFDM frames is of decisive importance for this method. The m-sequence is added directly to cyclic extension signal in the time domain. By utilizing the autocorrelation characteristics of m-sequence, efficient frame synchronization can be achieved. And we also consider frequency offset estimation simultaneously. The proposed frame synchronization method can be applied to the OFDM-based mobile multimedia communication systems.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.228-231
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• 2008

For a satellite data communication, the technology of frame synchronization is widely used between a sender and a receiver. Last year, we suggested zero-loss frame synchronization [1] using pattern search and using bits threshold search algorithm that is based on SIMD technology [2,3]. This algorithm could solve both of hardware and software drawbacks, which are frame loss and low processing performance. However, this algorithm didn't optimize the processing of output data, synchronized data, which caused overhead to the memory allocation and the memory copy. Consequently, the performance of the frame synchronizer application was degraded. In this paper, we enhance previous work using a circular buffer in order to optimize the output data processing. The performance comparison with the previous algorithm shows that the enhanced proposed approach dramatically outperforms in the output data processing speed.