• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.9A
• /
• pp.858-866
• /
• 2005

This paper proposes the method of frequency synchronization using the spectrum correlation in ATSC terrestrial DTV system. If the spectrum around pilot is severely distorted by multipath or mobile reception environment, the conventional algorithm using the pilot signal makes the estimation error of the frequency offset. Because the proposed algorithm acquires frequency synchronization using the correlation between the received specalm and the standard spectrum without the use of pilot, the proposed method can acquire frequency synchronization faster and more accurate than conventional algorithm. And this paper proposes new method for ATSC frequency synchronization without the use of pilot.

• Journal of Institute of Control, Robotics and Systems
• /
• v.21 no.8
• /
• pp.729-734
• /
• 2015

Improvement in the control strategy for continuous casting is a crucial requirement to enhance the slab's quality and to increase productivity. The mold oscillator adopts the dual cylinders due to its heavy weight, so the synchronized motion of two cylinders is an important aspect when precise control is needed. The conventional method uses the master-slave control applied to the valve input reference, but the synchronization performance should still be improved. This paper proposes a novel synchronization algorithm for dual cylinders used in a mold oscillator. The master-slave concept is applied to the target reference position, that is, the slave target reference position is controlled to match the slave cylinder's position with the master cylinder's position. In the simulation based on a Simulink model, the proposed algorithm shows a better synchronization performance in aspect of the mean of the absolute error and the peak synchronization error.

• Journal of Institute of Control, Robotics and Systems
• /
• v.19 no.3
• /
• pp.248-255
• /
• 2013

This paper proposes the architecture of the RILS (Robot-in-the-Loop-Simulation) consisting of the robot, the virtual robot, and the avatar robot which is the type of virtual robots operating according to the robot status and behavior. And the synchronization algorithm for mobilization part of the avatar robot is suggested, which reduces the difference between behaviors of the robot and those of the avatar robot. This difference occurs due to the environmental and mechanical mismatches between the robot and avatar robot. In order to reduce this difference in robots behaviors, the synchronization algorithm controls the avatar robot based on the data observed from the robot's behavior. The proposed architecture and the synchronization algorithm are validated from some simulation results.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37B no.11
• /
• pp.1022-1032
• /
• 2012

In OFDMA-based wireless mesh networks, synchronization of carrier frequencies among adjacent nodes is known to be difficult. In this paper, a distributed synchronization technique is proposed to solve the synchronization problem in OFDMA-based wireless mesh networks by using the bio-inspired algorithm. In the proposed approach, carrier frequencies of all nodes in a mesh network are converged into one frequency by locally synchronizing the frequencies of adjacent nodes. It may take a long time to be converged in some topologies since the convergence characteristic of carrier frequencies in a mesh network may vary depending on the size of the network and deployment of nodes. It is shown that fast frequency synchronization, not heavily depending on the topology, can be achieved through the proposed algorithm with an adjustable weight.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.27 no.8B
• /
• pp.809-818
• /
• 2002

In this paper, we propose a fast cell search algorithm keeping compatible with the standard cell search algorithm of the WCDMA system. The proposed algorithm can acquire the synchronization of slot and frame times, and the code group identification using only one synchronization channel while the standard algorithm employs two synchronization channels called P-SCH and S-SCH. The proposed synchronization channel structure is the same as the P-SCH structure of the WCDMA system. However, the P-SCH is modulated with a specific polarization code, which is one element of new code group codes. The proposed algorithm can reduce both the BS' transmission power and the complexity of receiver as compared with the conventional one since only on synchronization channel is used. It is shown through the computer simulation that the proposed algorithm yields a significant improvement in terms of cell search time compared with the standard especially in low SNR environments.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.9 no.4
• /
• pp.51-57
• /
• 2013

Research on calibration of array antenna has become a hot spot in the area of signal processing and it is necessary to obtain the phase mismatch of each antenna channel. This paper presents a new calibration method for an array antenna system. In order to calibrate the phase mismatch of each antenna channel, we used primary synchronization signal (PSS) which exists in LTE downlink frame. Primary synchronization signal (PSS) is based on a Zadoff-Chu sequence which has a good correlation characteristic. By using correlation calculation, we can extract primary synchronization signal (PSS). After extracting primary synchronization signal (PSS), we use it to calibrate and reduce the phase errors of each antenna channel. In order to verify the new array antenna calibration algorithm which is proposed in this paper, we have simulated the proposed algorithm by using MATLAB. The array antenna system consists of two antenna elements. The phase mismatch of first antenna and second antenna is calculated accurately by proposed algorithm in the experiment test. Theory analysis and MATLAB simulation results are shown to verify the calibration algorithm.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.9 no.1
• /
• pp.33-41
• /
• 2014

This paper presents a IEEE1588 based clock synchronization technique for a sRIO (Serial RapidIO) network which is applied to a submarine system. Clock synchronization plays a key role in the success of a networked embedded system. Recently, the IEEE1588 algorithm making use of dedicated chipset has been widely used for the synchronization of various industrial applications. However, there is no chipset available for the sRIO network that can offer many advantages, such as low latency and jitter. In this paper, the IEEE1588 algorithm for a sRIO network is implemented using only software without any dedicated chipset. The proposed approach is verified with experimental setup.

• Journal of Korea Multimedia Society
• /
• v.1 no.1
• /
• pp.18-25
• /
• 1998

The basic requirements of distributed multimedia systems are intramedia synchronization which asks the strict delay and jitter for the check period of media buffer and the scaling duration with periodic continuous media such as audio and video media, and intermedia synchronization that needs the constraint for relative time relations among them when several media are presented in parallel. In this paper, a distributed intermedia synchronization algorithm that solves the intermedia synchronization problem by using variable service rates based on the fuzzy logic is designed and then the performance is evaluated through simulation.

• Journal of Information Processing Systems
• /
• v.15 no.2
• /
• pp.271-287
• /
• 2019

The synchronization scheme based on moving average is robust and suitable for the same rule to be adopted in embedding watermark and synchronization code, but the imperceptibility and search efficiency is seldom reported. The study aims to improve the original scheme for robust audio watermarking. Firstly, the survival of the algorithm from desynchronization attacks is improved. Secondly, the scheme is improved in inaudibility. Objective difference grade (ODG) of the marked audio is significantly changed. Thirdly, the imperceptibility of the scheme is analyzed and the derived result is close to experimental result. Fourthly, the selection of parameters is optimized based on experimental data. Fifthly, the search efficiency of the scheme is compared with those of other synchronization code schemes. The experimental results show that the proposed watermarking scheme allows the high audio quality and is robust to common attacks such as additive white Gaussian noise, requantization, resampling, low-pass filtering, random cropping, MP3 compression, jitter attack, and time scale modification. Moreover, the algorithm has the high search efficiency and low false alarm rate.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.9 no.2
• /
• pp.449-454
• /
• 2008

As demand for the application in multimedia networks is increasing rapidly, it is important to provide these services in Mobile Environments (ME). Obtaining to multimedia services which satisfy synchronization constraints in ME and improving the delay time and Quality of Service(QoS) between media streams to be presented, new specification model has to be proposed. In this paper we propose Mobile Synchronization Model(MSM) as a new specification model for describing efficiently the QoS and the delay time. Also, we propose the multimedia synchronization algorithm where is a dynamic synchronization method that minimizes the effects of adaptive transmission delay time. The proposed model has higher the guarantee of QoS such as the loss rate and the playout rate than it of the previous work.