• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.3049-3051
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• 2005

본 논문은 UWB(Ultra Wide Band) 펄스 기반의 단일 송수신을 통한 근거리 무선측위 시스템 및 방법에 관한 것으로서, UWB 펄스의 높은 시간 분해능을 이용하여 근거리에서 높은 정밀도를 가지고 태그의 위치를 획득할 수 있다. 특히, 마스터-슬레이브 형태로 구성된 비콘(beacon)들 간의 사전 설정을 통해 마스터 비콘과 무선측위 대상인 태그 사이의 단일 송수신만으로 ToA(Time of Arrival) 및 TDoA(Time Difference of Arrival) 기법을 적용할 수 있도록 하며, 이로써 태그의 신호 송신을 최소화하여 태그의 저전력 동작을 가능케하는 UWB기반 단일송수신을 통한 근거리 무선측위 시스템이다.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.185-186
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• 2007

In this paper, We propose the selective detection scheme based on pulse repetition considering Bit Error Rate (BER) performance and complexity of noncoherent Ultra Wide Band (UWB) systems. To consider system complexity, the proposed scheme transmits the UWB signals by pulse repetition at the transmitter, like the conventional Pulse Repetition Coding (PRC). However, to effectively improve BER performance of the system the proposed scheme performs selective detection by estimating the Signal-to-Noise Ratio (SNR) of the received pulse-repeated signal at the receiver. Hence, the proposed scheme effectively improves BER performance of the noncoherent UWB systems without increase of the system complexity, as compared to the conventional PRC algorithm.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.308-311
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• 2015

Because worldwide interest in the health is increased, the real-time health monitoring system has been demanded to be more convenient non-contact and precise medical devices than conventional. Therefore we developed the blood pressure monitoring system using UWB(Ultra Wide Band) radio wave which contact to the human body through the radar and continuously collect a movement signal of the blood vessel. Then the collected data including pulse rate, systolic blood pressure, diastolic blood pressure is processed in real time. The system monitors and controls through a program-based embedded LCD(Liquid Crystal Display) using Qt GUI(Graphic User Interface) to be displayed in real time. We implement the system as a embedded system because of reducing the size of the limited resources. Existing PC GUI design mode is used relatively large memory, therefore it requires more CPU(Central Processing Unit) capacity and processing time.

• Journal of Korea Multimedia Society
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• v.9 no.1
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• pp.51-58
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• 2006

In this paper, we evaluated Ultra Wideband MC-CDMA system which is the combination of DS-CDMA and OFDM systems, which have been drafting in current standardization for IEEE802.15.3a. Too many Rake Fingers are demanded in the DS-CDMA system to detect multi-path signals, which results in high system complexity. OFDM system fails to qualify for FCC certification unless frequency hopping is off. MC-CDMA has lower complexity compared to DS-CDMA and shows good performance against frequency selective fading. In addition, for a wide-band communication, less radio power per spectrum is allowed in the MC-CDMA system than in an OFDM system. The MC-CDMA system is analyzed by a numerical formula and compared with DS-CDMA and OFDM by a computer simulation.

• Journal of Broadcast Engineering
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• v.18 no.6
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• pp.911-918
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• 2013

The proposed print antenna using Finite Difference Time Domain(FDTD) method is analyzed in this paper. A low radiation resistance and an ultra-wide band of this antenna are also presented. The propagation process of the reflected wave and the electric field distribution in the time domain are calculated in respectively. The antenna parameters are optimized for the maximum band width, return loss, input impedance, and radiation pattern in the frequency domain using Fourier transforming. The experimental bandwidth of the antenna is 1.85GHz~6.35GHz for the VSWR less than or equal to 2.0. The measured results are relatively in good agreement with the FDTD results. The proposed antenna can be applied to various applications such as UWB, broadcasting-network system.

• The Journal of the Korea institute of electronic communication sciences
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• v.3 no.2
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• pp.53-57
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• 2008

This paper designed and fabricated the printed dual monopole antenna with CPW feeder for PCS and UWB(Ultra-Wide Band) band. In this paper, modified dual monopole antenna is proposed transform conventional monopole antenna to get dual band frequency. The dual monopole antennas have dual band, broad bandwidth and omni-directional radiation patterns, as it is the conventional monopole antenna. As one monopole operated a stub to match feed line with antenna, we are obtained easy an ideal impedance matching. It is increased band width of impedance. The antenna bandwidth is about 1350MHz (1.69~2.04[GHz]z]) at 1st resonance frequency, 2,670MHz (4.33~6[GHz]) at 2nd, resonance frequency, and, 3,980MHz (6.1~10.08[GHz]) at 3th resonance frequency on VSWR$$\leq_-$$2, and then we can be got not only 1.75~1.87 [GHz] PCS band but also, UWB band.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.985-988
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• 2005

The international standards of high-rate WPAN (Wireless Personal Area network) are under development by IEEE802.15 WPAN TG3 (Task Group 3). The study area of TG3 mainly consists of three parts: high rate physical and media access control layer in 2.4GHz ISM (Industrial Scientific Medical) non licensed frequency band; an alternative high rate physical layer by using UWB (Ultra Wide Band); and another alternative high rate physical layer based on millimeter wave. This paper describes the standardization trends of UWB and millimeter wave.

• The Journal of Society for e-Business Studies
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• v.13 no.2
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• pp.195-212
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• 2008

The demand of wireless communication system is increasing due to the development of computers and other digital media appliances. In particular, new wireless communication technology is necessary for implementation of home network since a lot of data transmission is occurred. Recently, two wireless communication technologies, Ultra Wide Band(UWB) and 60GHz band wireless communication technology, have being developed for high-speed data transmission and Wireless Personal Area Network(WPAN). In this paper, we study the present development condition of these two technologies and a role of them in home network. We also suggest the method to implement the home network using all wireless communication technologies. At the end, we outlook the market of WPAN and High Definition Multimedia Interface(HDMI).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.12
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• pp.1297-1307
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• 2009

The purpose of this paper is to propose a detection algorithm and a tracking algorithm based on silent time using MB-OFDM UWB(Multi-Band Orthogonal Frequency Division Multiplexing Ultra Wide Band) receiver in order to satisfy DAA(Detect And Avoid) regulation of Korea to permit UWB in 3.1~4.8 GHz. In DAA regulation of Korea, if UWB device receives a signal more than -80 dBm/MHz from the victim system during UWB operation, the UWB system should avoid the collision within 2 sec. In this paper, we proposed the detection algorithm to detect the victim signal received by －80 dBm/MHz for the avoidance process that changes the operating UWB frequency to other UWB frequency and the subcarrier tracking algorithm to follow up the subcarrier positions of the victim signal for the tonenulling avoidance process that decreases the TX power of subcarriers occupied by the victim signal by -70 dBm/MHz. The performance of the detection algorithm and the tracking algorithm suggested in this paper is verified in simulation results considering various conditions.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.338-343
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• 2015

In order to avoid the interference from existing narrowband communication systems, this paper proposes a compact band-notched UWB (ultra wideband) antenna with size of $12mm{\times}22mm{\times}1.6mm$. Transmission line model is applied to analyzing wide impedance matching characteristic of the modified base antenna, which has a gradual stepped impedance feeder structure. The proposed antenna realizes dual band-notched function by combining two biased T-shaped parasitic elements on the rear side with a window aperture on the radiation patch. The simulation current distributions of the antenna reflect resonant suppression validity of the two methods. In addition, the measured radiation characteristics demonstrate the proposed antenna prevents signal interference from WLAN (5.15-5.825GHz) and WiMAX (3.4-3.69GHz) effectively, and the measured patterns show the antenna omnidirectional radiation in working frequencies.