• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.11
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• pp.79-86
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• 2005

This paper describe a method for measuring line impedance as a function of frequency for an energized powerline in normal operation. A small sinusoidal signal of a powerline communication utility frequency $30khz\~1Mhz$ band is continuously injected into the line, and a implemented impedance analyzer calculates the indoor powerline channel impedance from the measured magnitude and phase of resulting voltage and current. The impedance measurement is executed over a range of frequencies to produce a wideband impedance versus frequency characteristic. Implemented impedance analyzer can analysis powerline communication environments measuring line impedance due to load caused in indoor. And measured analysis information through the database can use to evaluate performance of modem and to decide test environment standard.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.5
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• pp.95-102
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• 2014

In this paper, we propose the high speed PLC-based automatic control system for a smart LED streetlight. The proposed the automatic control system were constructed of a power line modem part and monitoring part, streetlight controller part for the high speed communication frequency band and streetlight ballasts characterization and real-time remote control using a high-speed PLC network, and it was designed to meet to lighting grades conditions of KS road lighting standards. The proposed automatic control system were easy monitoring of the power consumption using PC through to the comparison result of the existing streetlight system. As a result, it was confirmed to the possibility of efficient operation for the real-time monitoring and maintenance by induction of reasonable power consumption through to the LED streetlight state checking and remote-control. In addition, we proved to improvement of expected effects for the power cost savings, the energy efficiency, and streetlight differentiation and advanced.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.9A
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• pp.983-990
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• 2004

In this paper, we calculated the input impedance of the power line communication(PLC) networks using medium voltage power line. First of all, we proposed input and output teoninal model of PLC network, and calculated the input impedance applying the attenuation constants by radiation loss, conductor loss, dielectric loss. From the calculation result, we knew that the attenuation by radiation loss was largest, and the input impedance appears like a standing wave fonn with a fixed cycle because the high reflection at the input terminal for the characteristic impedance of the power line is very large. And also the cycle of input impedance depends on the coaxial cable length, and the amplitude depends on the characteristic impedance of power line and losses. From the measurement result, calculated result was very similar to the measured result.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.1
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• pp.8-11
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• 2019

In this paper, a Ku-band 50-W internally-matched power amplifier is designed and fabricated using a CGHV1J070D GaN HEMT from Wolfspeed. To obtain the same magnitudes and phases for the output signals of the unit transistor cells, which constitute a power transistor, a slit pattern and an asymmetric T-junction are used in the input and output matching circuits. The internally-matched power amplifier is fabricated on two different thin-film substrates with relative dielectric constants of 40 and 9.8, respectively, and is measured under pulsed conditions with a pulse period of $330{\mu}s$ and a duty cycle of 6%. The measured results show a maximum output power of 50~73 W, a drain efficiency of 35.4~46.4%, and a power gain of 4.5~6.5 dB from 16.2 to 16.8 GHz.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.6
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• pp.744-750
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• 2020

In this paper, we propose a deep learning based transmit power control (TPC) scheme to improve the spectral and energy efficiency of wireless communication systems. In the wireless communication system, the positions of multiple transceivers follow a uniform distribution, and the performances of spectral and energy efficiency for the proposed TPC scheme are analyzed assuming the Nakagami fading channels. The proposed TPC scheme uses batch normalization to improve spectral and energy efficiency in deep learning based training. Through simulation, we compare the results of the spectral and energy efficiency of the proposed TPC scheme and the conventional one for various area sizes that limit the position range of the transceivers and Nakagami fading factors. Comparing the performance results, we verify that the proposed scheme provides better performance than the conventional one.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.6
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• pp.1-8
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• 2011

Power Line Communication (PLC: Power Line Communication) to propagate the current power lines are in every household of the existing infrastructure is the most extensive network configuration. In addition, the cost required for network configuration, the advantage of almost zero for the investors and is sufficient to attract the attention of operators. The PLC is supply power to power lines used the voice and data communication technologies put it on KHz ~ tens of hundreds of high-frequency signal MHz. But because uses power lines as existing wireless communications systems will occurs interference. The notch filters of a common way to eliminate the interference are used. In this paper, a dynamic high-performance notch filter applying CIC filter performance was verified through MATLAB and was implemented using a TI's TMS320C6416T DSP board.

• Journal of Korea Multimedia Society
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• v.8 no.5
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• pp.660-669
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• 2005

In this paper 10Mbps master-slave based PLC modems are tested for measuring and analyzing both network and application level performances in the general buildings. The devices under test consist of one master PLC modem and three slave modems. The selected parameters for inspecting the performances are throughput, latency and frame loss rate from the RFC 2544, and one-to-many and many-to-one throughput from the RFC 2285. The results of the performance test show that the PLC modems have Performed better in data transmission when the frame size is increased and the transmission speed is decreased. It is expected that these results will be useful to analyze the effect of noise sources when compared to the performance test under the noiseless environments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.119-124
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• 2010

The MAC layer in ad-hoc network which makes network of nodes without infrastructure for a time has became an issue to reduce delay, allocate fairly bandwidth, control TX/RX power and improve throughput. Specially, the problem to reduce power consumption in ad-hoc network is very important part as ad-hoc devices use the limited battery. For solution of the problem, many power control algorithms, such as distribute power control, PCM (Power Control MAC) and F-PCF (Fragmentation based PCM), are proposed to limit power consumption until now. Although the algorithms are designed to minimize power consumption, the latency communication zone is generated by power control of RX/TX nodes. However the algorithms don't suitably reuse the space. In this paper proposes the algorithm to improve data throughput through Spatial Reuse based on a power control method.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2019.06a
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• pp.110-111
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• 2019

본 논문에서는 최근 부족한 전파자원을 대체할 수 있는 대안으로 부상하고 있는 가시광 통신을 이용하여 실내에서의 멀티미디어 컨텐츠 전송 방안을 제시한다. 건물내의 조명들을 가시광 모뎀으로 이용하고, 조명들이 연결된 전력선을 통신 선로로 이용한 전력선 통신을 이용하여 건물 내 통신망을 구성하였다. 본 연구에서 제시하는 가시광 통신을 이용한 건물 내에서의 멀티미디어 컨텐츠 전송 방법은 일반 건물 내에서의 멀티미디어컨텐츠 전송 및 전자기파 등의 사용이 제한되는 병원 내에서의 진단 영상정보 등의 전송에 활용이 가능할 것으로 기대된다.

• Information and Communications Magazine
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• v.8 no.2
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• pp.56-61
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• 1991