• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.7 no.5
• /
• pp.1-12
• /
• 2008

In this paper, we described about core technologies required for the seamless service implementation and the communication system structure conceiving required for call & response services in order that the real-time traffic information service is consecutively provided to the vehicle moving at high speed. The SMART highway service is the information communication environment build-up concept which the real-time C&R service is comprised of the vehicle moving with 160km/h above. It was possible in case of being the low speed car in the DSRC system structure. However, there is a limit in the high speed environment as the DSRC system like a convention. In this paper, we proposed the structure of fitting for the SMART highway environment using the hand-over technique compositing the base station and several repeaters of DSRC system.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.48 no.11
• /
• pp.9-16
• /
• 2011

We need to establish standard for the ICT based on train control system. In order to solve the ISI problem, this paper evaluate the performance of OFDM and FDE system. We seem that OFDM system is better than FDE system. In order to solve ISI problem, SC System is needed a equalizer. And another method is OFDM System. If system is used SC with a equalizer, It is better than OFDM in terms of PAPR, but this system is not easy to use Multi-Antenna technique, i.e., beam-forming and MIMO-multiplexing. And If system is used high-order modulation, BER performance is worse than OFDM. If we think about in terms of PAPR problem, considerations are considered not significant because the size of relays is not considered in the communication between trains and ground.

• Proceedings of the Korea Contents Association Conference
• /
• 2003.05a
• /
• pp.443-448
• /
• 2003

Ministry of Information and Communication(MIC) requires telecompanys to be base station sharing in order to prevent the duplicated investment and environmental destruction due to indiscreet constructions of a basestations for enlarging its own service area among telecompanys. This paper discussed the troubles of mobile communication services to be generated in common-basestation at the subway, such as factors of power obstacles, communication equipment and establishment obstacles. The content of this paper is helpful in organizing the basestation sharing of IMT-2000 and the 4th generation mobile system, and provides the basic of a higher quality service for common-service communication.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.26 no.4B
• /
• pp.520-527
• /
• 2001

육상이동위성 채널에서 고속 광대역의 정보를 효율적으로 전송하기 위한 최적 방안으로 OFDM(Orthogonal Frequency Division Multiplexing) M-ary PSK를 들 수 있다. 그러나 가입자 단말기 또는 위성중계기의 송신단 고출력 증폭기(HPA : High Power Amplifier)를 전력효율적인 비선형 mode에서 동작할 때, OFDM M-ary PSK 시스템의 최대 전력 대 평균전력의 비(PAPR : Peak-to-Average Power Ratio)가 부바송파 개수만큼 선형적으로 커져 단일 반송파 변조방식에 비해 비선형 왜곡에 의한 성능 열화가 심각하다. 본 논문에서는 이와 같은 성능 열화를 개선하기 위하여 전송채널에서 대역효율과 BER(Bit Error Rate) 성능이 우수한 PC(Parallel Combinatory) OFDM 방식과 개선된 PAPR을 가지는 PTS(Partial Transmit Sequence) OFDM 방식을 결합한 Combined PC & PTS OFDM 방식을 제안하고 그 성능을 분석하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.23 no.6
• /
• pp.661-668
• /
• 2012

In this paper, a dual-fed small ICS repeater antenna with high isolation is designed, fabricated, and measured. Bandwidth and gain are optimized by changing the stub lengths near main patch and power divider, and also by changing the size of parasitic patch. To improve the isolation characteristic of the antenna, a dual-feeding method is applied in designing the antenna. The fabricated antenna has a VSWR less than 2, a gain over 7 dBi, and an isolation between the donor and the server antennas less than -65 dB from 1,920~2,170 MHz for 3G mobile communication.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2014.10a
• /
• pp.182-185
• /
• 2014

In this paper, the ADC performs research and development for high speed data transfers to minimize the optical delay. Have more $6{\mu}s$ delay in the data signal converting optical repeater transmission system existing there has been a limit on the high-speed data transmission, and signal conversion. The need to develop a new technique to reduce the delay in time within $2{\mu}s$ data signal converted by using this direct conversion system. It is desired the development of the core technologies necessary for the signal transduction component, such as mobile communications LTE, LTE advanced service transport network is established, the delay time $3{\mu}s$ technology for reducing the delay time in the signal converting a revolutionary step is applied in this paper we have developed an ADC.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.5A
• /
• pp.381-390
• /
• 2009

In this paper, we propose a seamless intra MR-BS handover scheme based on IEEE802.16j transparent. The proposed scheme estimates the outage probability of mobile stations at a base station, finds the optimum relay user, and provides low handover latency for seamless data transmission. The simulation results show that the proposed scheme outperforms the conventional handover schemes in terms of the handover latency by 65% of conventional scheme. Moreover, the proposed scheme exhibits lower packet error rate compared with the conventional handover scheme when a mobile station moves to outside of the cell coverage and reduce both outage probability and the number of handover about 50% from setting forgetting factor and redundant threshold.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.9 no.3
• /
• pp.285-290
• /
• 2016

In rural area, our farmers confront decreasing benefits owing to imported crops and increased cost. Recently, the government encourage the 6th Industry that merges farming, rural resources, and information and communication technology. Therefor the government makes an investment in supplying 'smart greenhouse' in which a farmer monitor growing crops and environment information to control growing condition. The objective of this study is developing an Moving Monitor and Control System for crops in green House. This system includes a movable sensing unit, a controlling unit, and a server PC unit. The movable sensing unit contains high resolution IP camera, temperature and humidity sensor and WiFi repeater. It rolls on a rail hanging beneath the ceiling of a green house. The controlling unit contains embedded PC, PLC module, WiFi router, and BLDC motor to drive the movable sensing unit. And the server PC unit contains a integrated farm management software and home pages and databases in which the images of crops and environment informations. The movable sensing unit moves widely in a green house and gathers lots of information. The server saves these informations and provides them to customers with the direct commercing web page. This system will help farmers to control house environment and sales their crops in online market. Eventually It will be helpful for farmers to increase their benefits.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.22 no.5
• /
• pp.552-559
• /
• 2011

In this paper, the frequency reconfigurable antenna is proposed and designed. The proposed antenna is designed using the vertically stacked dipole structures and have the operating band for Cellular, PCS/WCDMA/Wibro/WiFi and WiMAX. The operating frequency band is selected by three pair of PIN diodes using the voltage difference between each dipole antenna and feeding transmission lines. The proposed antenna meets the required operating bandwidth and the maximum gain for each frequency band are measured as 6.3 dBi, 5.4 dBi and 5.8 dBi, respectively. The proposed antenna in this paper can be applied for the future mobile small base station or repeater antenna because this antenna can provide the small size and high gain features.

• Journal of Broadcast Engineering
• /
• v.8 no.1
• /
• pp.54-62
• /
• 2003

This paper presents a Soccer Game 3D Reencatment System which reenact the Important scene like getting a goal with image processing and computer graphics technologies. KBS Research Institute of Technology has developed the 3D Reenactment System of Soccer Game called ‘VPlay' to provide TV viewers with fresh images in soccer games. Vplay generates the reenactment of exciting and important soccer scenes by using computer graphics. Vplay extracts legion of players from video with color information, and then computes precise positions of players on the ground by using global motion estimation model and playground axis transformation model. The results are applied to locomotion generation module that generates the locomotion of virtual characters automatically. Using predefined motion and model library, Vplay reenacts the important scene in a quick and convenient manner Vplay was developed for live broadcasting of soccer games that demands rapid producing time and was used efficiently during past WorldCup and Asian Game.