• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.1
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• pp.69-76
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• 2015

In this paper, we propose and analyze a M-ary transmission scheme in time hopping ultra-wide band(UWB) system using mutually orthogonal modified Hermite polynomial(MHP) pulses. The proposed M-ary transmission scheme employs the orthogonal property between different ordered pulses and N data bits make the M-ary signals by linear combination of M MHP pluses. The theoretical analysis and simulation results show that the proposed system has better performance and higher data rate than conventional M-ary UWB system. We derive the general form of correlation function for MHP pulses and analyze bit error rate(BER) performance over additive white Gaussian noise(AWGN) with the presence of timing jitter. We show that the proposed system has the improved BER performance and robustness to timing jitter and low power spectrum density compared with conventional M-ary UWB system.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2003.06a
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• pp.213-216
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• 2003

UWB 통신 기술은 초광대역 특성 때문에 높은 전송 속도와 저전력 통신이 가능하여 의료장비에 응용이 가능하며, 특히 유선이라는 제약성으로 큰 불편을 겪고 있는 ECG시스템에 적용되어질 수 있다. 따라서 근거리 무선 통신 기술로 급부상하고 있는 UWB 통신 기술의 응용을 위해 UWB 신호 특성 및 변조 방식의 연구가 행하여져야 한다. 이에 본 논문에서는 UWB에 사용가능한 각종 펄스의 특성과 적용하고자 하는 시스템 환경에서 발생할 수 있는 UWB 신호의 간섭 영향을 분석하였으며, 간단한 UWB 송수신 시스템을 시뮬레이션 하였다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.7
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• pp.18-22
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• 2010

In this paper, we propose and analyze the two way ranging (TWR) positioning technique using ultra wideband (UWB) for indoor environment. We employed IEEE 802.15.3a channel as a simulation environment and used to time of arrival (TOA) algorithm. UWB technology in a low transmission power the less the effect of interfering with the existing system, the frequency can be shared so that it can improve the spectral efficiency. And, positioning technique based on UWB with a very narrow pulse width has high accuracy in indoor environment. From the simulation results, it is analyzed the probability of error and positioning performance for channel effects and confirmed usefulness of the proposed scheme.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.11
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• pp.36-43
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• 2012

Ultra-wideband propagation measurement results for body area network scenarios are presented. We assumed several different scenarios for around-body and on-body propagations, and for each scenario, we conducted both time domain and frequency domain measurements in an anechoic chamber. For the around-body case, we investigated the effects of human body parts blocking line-of-sight, which could be accounted for by diffraction. On-body measurement results indicate a more complicated propagation mechanism exists in on-body propagation than in around-body propagation and antenna characteristics are affected.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.1A
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• pp.1-12
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• 2002

Ultra Wideband (UWB) system uses wide band signal, which power spectral density likes as a noise floor, so UWB system can be used high speed communication without interfering with other communication system. As this system doesn't use radio frequency carrier. Its structure would be very simple and consume very low power. For the first time, we adopted Rayleigh monopulse multiple access system. And under the AWGN, we analysis and compare error probability, the number of user and data rate of the two methods that pulse position modulation and antipodal. In the result, We concluded that the antipodal method had much better probability of error, the number of user and data rate than PPM.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.9
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• pp.2003-2008
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• 2013

In this paper, a design method for a ultra-wideband printed semi-circular-shaped dipole antenna operating in the band of 1-15 GHz is studied. The effects of the gap between the two arms of the semi-circular-shaped dipole and the radius of the semi-circle on the input reflection coefficient and gain characteristics are examined to obtain the optimal design parameters. The optimized printed semi-circular-shaped dipole antenna is fabricated on an FR4 substrate and the experimental results show that the antenna has a desired extremely wideband characteristic with a frequency band of 1-15 GHz (175%) for a VSWR < 2.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.8C
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• pp.814-821
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• 2009

In an ultrawide band (UWB) indoor wireless localization, time of arrival (TOA) parameter estimation techniques have some difficulties in acquiring a reasonable TOA estimate because of the clustered multipath components overlapping or random time intervals mainly due to non line-of-sight (NLOS) environment. In order to solve that problem and achieve an excellent UWB indoor wireless localization, we propose a UWB signal model and a robust TOA parameter estimation technique that has little effect on the clustered problems unlike the conventional technique. Through simulation studies, the validity of the proposed model and the TOA estimation technique are examined. The performance of estimation error is also analyzed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.67-68
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• 2013

In this paper, a super wideband printed dipole antenna operating in the band of 1-15 GHz is studied. A semi-circular-shaped dipole element is used to obtain a super wideband characteristic. Optimal design parameters are obtained by analyzing the effects of the gap between the two arms of the semi-circular-shaped dipole and the radius of the semi-circle on the input reflection coefficient and gain characteristics. The optimized printed semi-circular-shaped dipole antenna is fabricated on an FR4 substrate with a dimension of $100mm{\times}100mm$. Experimental results show that the antenna has a desired super wideband characteristic with a frequency band of 1-15 GHz (bandwidth ration 15:1, 175%) for a VSWR < 2.

• Electronics and Telecommunications Trends
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• v.25 no.6
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• pp.123-135
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• 2010

고대역폭을 요구하는 새로운 서비스의 등장이 계속 이어지고 있어 수 년내 초광대역 시대가 도래할 것으로 예상된다. 이에 대비하여 다양한 광전송대역폭확장 기술이 등장하고 있으며, 나아가 시장 선점을 위한 실상용화를 서두르고 있다. 본 고에서는 초광대역 서비스 전달을 위해 요구되는 광전송망과 핵심 요소기술들을 살펴보고, 최근 경쟁적으로 기술 확보에 관심을 기울이고 있는 100Gbps 변복조, 100Gbps OTN, 100Gbps 이더넷 기술에 대한 기술 동향과 모듈 개발 동향, 또한 100G 이후 등장이 예상되는 새로운 광전송 분야와 이를 위해 극복해야 할 한계 기술에 대해 기술한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.6C
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• pp.569-574
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• 2006

We derive the general power spectral density of functions of ultra-wide bandwidth (UWB) systems using a pulse position modulation. We propose a new UWB system with a preferable line spectrum properies and a good bit error rate performance.