• The KIPS Transactions:PartC
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• v.13C no.7 s.110
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• pp.881-888
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• 2006

The position of the bridged tap is determined by that of the outlet in most modern apartments, since most of the indoor wiring utilizes the bus wiring structure when deploying the indoor communication line. These bridged taps deteriorate transmission performance in the specific frequency at the time of high-speed multimedia communication, which uses a high frequency bandwidth, since the duality of return loss worsens and line attenuation increases rapidly. As a result, analysis on this phenomenon is required. In this study, the test model is created by modeling the intercommunication facility of the apartment that is the most representative residential house type, and by understanding the structure and the environment of the indoor wiring. Also, how the bridge tap affects performance is analyzed when the VDSL service is provided, so that problems of intercommunication lines can be identified and methods for improving the proper intercommunication line can be suggested, which is suitable for accommodating high-speed multimedia service of the future.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.10
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• pp.1821-1827
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• 2007

In this paper, an analytic transfer channel modeling function by impulse signal propagation effects in indoor power-line network are analysed. The modeled channel parameters of power line channel including background noise is applied to the OFDM system and we analysis BER for QPSK and 16-QAM modulation signals with simulation. By the representation of gain for OFDM modulation, we can estimate the characteristic parameters of OFDM in Broadband power line communication.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.1
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• pp.139-150
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• 1997

For high-speed networks, a new ring protocal is proposed in this paper. A ring network combined with destination removal can achieve much higher network throughput than the channel transmission rate. However, such a network exhibits fairness problems. Over a past few years, global fairness algorithms such as ATMR and Metaring have been proposed to solve such problems. But the ring access time delay and fairness in such networks are sensitive to the network parameters such as network size and traffic distribution. In addition to guaranteeing fair ring access to all nodes, there are several other important performance aspects in such networks. The one is that fairness is enforced while node throughputs are kept as high as possible. And another performance measure is access delay and more specifically Head-Of-Line(HOL) delay, i.e., the amount of time the first cell in the transmission buffer of a node has to wait before it accesses the ring. HOL delay is a mijor component in the transmission jitter of the synchronous traffic transmission. A key idea of the proposed ring protocol is to find the nodes that have much more chances to access the ring than any other nodes in the independently distributed node architecture. Since destined by many cells need to share a part of the bandwidths with the next node for the fairness in as much as performance degradation does not become critical. To investigate the performance behavior of the proposed ring protocol for various network condition,s several performance parameters wuch as ring access time delay, and throughput are compared with those of the ATMR and Metaring protocols using simulation package, SIMAN.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.05a
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• pp.243-247
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• 1999

For the purpose of LAN or data transmission line design with high speed and reliability using power lines, in this paper, we present CSK/SS-DS signal transmission characteristics simulations with changing channel characteristics due to impedance fluctuation. And we also simulated the signal transmissions with a strong impulsive burst noise and with a gaussian random noise. We introduce a simple channel equalization filtering method that solves the synchronization problem of CSK/SS-DS with fluctuating channel characteristics or low S/N ratio.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.1
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• pp.1-7
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• 1999

In this paper, we use the FDTD method to analyze crosstalk characteristics for high speed pulse signal on MTL(Multi-Transmission Line) in time domain. The FDTD results are compared to the results of SPICE modeling method and the experimental result. The FDTD method has higher accuracy of results than other methods, and it can analyze transmission characteristics of MTL regard to loss of conductor. We analyze crosstalk characteristics for pulse on MTL for lossless and loss case.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.829-832
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• 2005

This paper describes a wide-range dual-loop Delay Locked Loop (DLL) using Voltage Controlled Delay Line (VCDL) based on Transmission Gate(TG) inverters. One loop is used when the minimum VCDL delay is greater than a half of $T_{REF}$, the reference clock period. The other loop is initiated when the minimum delay is less than $0.5{\times}T_{REF}$. The proposed VCDL improves the dynamic operation range of a DLL. The DLL with a VCDL of 10 TG inverters provides a lock range from 70MHz to 700MHz when designed using $0.18{\mu}m$ CMOS technology with 1.8 supply voltage. The DLL consumes 11.5mW for locking operation with a 700MHz reference clock. The proposed DLL can be used for high-speed memory devices and processors, communication systems, high-performance display interfaces, etc.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.12
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• pp.33-38
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• 1996

In this paper, we modeled the complex dielectric constant and analyzed the projpagation characteristics of a FR-4 composite substrate with different compositions. From the wideband dielectric modeling and the propagation loss analysis of FR-4 composites that consists of FR-4 resin and E-glass reinforcement,we have found that the propagation loss and velocity increase with the volume fraction of FR-4 resin above 1 GHz. These results are helpful in determining to deisgn optimum substrate composition ratio and cross-sectional geometry of high-speed and high-density transmission line.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.5
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• pp.185-192
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• 2011

In this paper, we simulate and analyze performance of iterative coding scheme, double binary turbo code, for high speed power line communication (PLC) systems. PLC system has hostile environment for high speed data transmission, so error correction method is necessary to compensate effects of PLC channel. We employ the PLC model proposed by M. Zimmerman and Middleton Class A interference model, and system performance is evaluated in terms of bit error rate (BER). From the simulation results, we confirm double binary turbo code provides considerable coding gains to PLC system and BER performance is significantly improved as the number of iteration increase. It is also confirmed that BER performance increases as code rate is lager, while it decreases as the code rate is smaller.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.3
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• pp.251-256
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• 2018

In the case of a radar repeater that used for the trajectory tracking of a high-speed aircraft, it emits pulses of short width. For phase displacement of these signals a branch type phase shifter is used. The phase on the transmission line is changed by utilizing the variable reactance at the end of the displacement branch transmission line. Further, it is easy to control the high output signal, and there is an advantage that the insertion loss is not large even when the reactance fails. In this paper, we will discuss the fabrication test results of a 400 W class phase shifter that sequentially displaces the phase at $0^{\circ}$, $30^{\circ}$, $60^{\circ}$, $90^{\circ}$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.5
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• pp.731-738
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• 2002

In this paper, we analyzed a medium voltage power line characteristics considering the skin effect for high speed data transmission. Medium power-line characteristics impedance was obtained by the S-parameter method which is used in high frequency band. Power line channel characteristics was measured using it designed coupler, it is a wide band coupler between medium powe-line and measurement system. Attenuation characteristics along the frequency was decreased linearly when skin effect was considered but attenuation characteristics along the frequency was decreased linearly when skin effect was not considered. Impedance was showed lower and lower in proportional to frequency, and variation was decreased in proportional to frequency.