• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.8
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• pp.93-97
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• 2004

Since powerline for powerline communications (PLC) is designed for supplying electric power using 60 Hz wave, they will have different electrical behaviors for high data rate PLC whose bandwidth is allocated between 1 MHz and 30 MHz. Thus, it is necessary to investigate the different properties in this frequency bandwidth for the high data rate PLC. In this paper, low voltage (220V) powerline impedance for indoor high data rate PLC in between 1 MHz and 30 MHz is measured. For measurement a low voltage coupling unit is made and a vector network analyzer is used. A T-equivalent circuit of the low voltage coupling unit is obtained and then powerline impedance is derived by measuring the reflection coefficient of the total powerline network. With the method proposed, impedance is measured in case of a general korean apartment and its property is analyzed. Measurement shows that the average impedance is about 100Ω.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.2
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• pp.116-123
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• 2005

Chirp spread spectrum method using both time and frequency component is fit to time varying channel such as powerline channel. The used chirp symbol based on the CEBus standard is the unit symbol which sweeps from 100kHz to 380kHz over a 25㎲. To evaluate the performance of between Chirp-SS and DSSS, we measured the bit error rate under Gaussian channel. Simulation result is shown that Chirp-SS has a about 3[dB] gain of SNR than DSSS. To verify the performance of implemented modem, it is made up the powerline channel environment. After adding several noises to it, we examined the receiving status of modem. The implemented modem is able to receive the signal over the powerline channel with having several noises and capacitive loads.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.5
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• pp.345-352
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• 2004

Currently, high data rate PLC(Power Line Communications), up to 100 Mbps, which use frequency bandwidth between 2 MHz and 30 MHz is investigated very hard, and commercial PLC modem for low voltage powerline network (indoor) is coming soon into communication market. For the purpose of developing a fit communication system which has little distortion of signal and attenuation, it is surely necessary to know about channel environments of powerline. Especially, the impedance measurement of the powerline and impedance matching are very important. As is known, since medium-voltage powerline (22.9 ㎸) is still working, it is not so simple to measure the powerline impedance. In our study, a portable impedance measurement equipment is developed. It consists of coupling capacitor, a drain coil and impedance matching transformer. The equipment is easily connected to medium voltage line and impedance of power line is measured using a network analyzer. Also, measurement results are used for impedance matching of PLC signal. In fact, matching transformer with several different impedances are used. The matching transformer is connected between coupling capacitor and signal port. In this paper, the developed portable impedance measurement equipment and impedance measurement results are presented. Also impedance matching technique using matching transformers will be explained. We showed the result of the improved performance by the impedance matching.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.42 no.3
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• pp.39-44
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• 2005

In this paper, we use the 5-ary frequency shift keying method for robust powerline communication. To transmit the data by the 3-ary carrires among 5-ary carrirers and three carriers are 115kHz, 120kHz and 125kHz. Each time of three carrires is 0.33ms and total transmitting time duration from zero crossing point has 1ms. We use the dummy carriers which are 50kHz and 350kHz for monitoring the powerline channel state, dummy signal duration is received during 1ms. Experimentation result is shown that the implemented PLC transceiver has better than chirp transceiver at the capacitive load testing in spite of low transmission power.

• Proceedings of the IEEK Conference
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• 2000.06a
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• pp.77-80
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• 2000

In this paper, we implemented the voice modem using the multicarrier DS-CDMA in powerline channels. Both TMS320C5402 of Texas Instrument and FPGA FLEX 10K EPF10K100ARC240 of ALTERA are used to realize the proposed system. For robustness in the powerline channel, we used multicarrier DS-CDMA modulation, convolutional encoding/Viterbi decoding, and interleaving. Finally, we showed satisfactory performance in the laboratory experiment.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.280-283
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• 2001

Recently Many technologies of the Powerline communication are proposed these technologies used high carrier frequency for high speed and stability, but high carrier frequency is restricted by the low of electric wave. So we will propose electric monitoring system that used the commercial powerline communication modem, isn't restricted by the low. Our objects are, first, we compared the low in korea, EU(CENELEC), and USA(FCC). second, proposed a spec of the powerline communication modem. third, design that the electric monitoring system using commercial A/D converter control and manage the electric equipment.

• The Journal of Information Technology
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• v.8 no.3
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• pp.25-33
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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$\sim$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.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.42 no.4
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• pp.53-62
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• 2005

In this paper, we implement a 40kbps narrowband powerline communication modem which is able to high transfer rate than conventional powerline communication technology by using the chirp technique that is one of the spread spectrum techniques. A modem that implement in this paper used the CEBus standard and a symbol that the linear variable frequency signal of 100$\sim$380kHz is kept for 25us. Experimental results, we verified the possibility that communication technology with the Chirp technique can make transfer rate more than 40kbps at narrowband communication.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.4A
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• pp.325-329
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• 2007

In this paper, the modem based on EIA-709.2-A PL of powerline communication techniques which are considered to be important technologies for in-home control network systems was implemented via VHDL. In order to have the robust properties against existing noises over powerline channels, the information data using eight symbols was transmitted by transmitter and the receiver is composed of matched filter, averager, decision and detection parts in order to detect the right data from the received signals. The implemented PLC transceiver was downloaded into Altera's EP1S25C672 FPGA and the operation was verified successfully.

• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.211-213
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• 2000

This paper represent powerline communication system for data transmission. Powerline communication model is the Local Area Network which length is 250m in SKKU. Simulation is applied DS-CDMA. Convolutional coding, Viterbi decoding and Interleaver. Simulation result say that proposed system is superior performance and available in present.