• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.2069-2070
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• 2006

본 논문은 UWB(Ultra Wideband) 펄스 기반의 단일 송수신을 통한 UWB 레인징 시스템에서 거리산출의 모호성을 제거하고 그 성능을 향상시키기 위한 듀얼윈도우처리기법을 새롭게 제안한다. 일반적으로 UWB 레인징시스템은 UWB 전송펄스의 높은 시간분해능을 이용하여 거리를 산출하는데, 비가역성(Non-coherent) UWB 송수신기 구조에서는 신호가 언제 수신 될지 모르는 정보 표본값들로부터 최초도착 성분을 추출하게 되고 이로 인해 거리산출오차가 크게 발생되어 진다. 실내무선채널환경(CMI)의 UWB 레인징 시뮬레이션 결과 본 논문에서 제안된 듀얼윈도우처리기술을 적용 시 1m 거리산출 확률오차기준으로 대략 98% 정확도를 보인 반면에 그렇지 않은 경우는 75%이하의 레인징 정확도 성능을 나타낸다

• ETRI Journal
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• v.35 no.6
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• pp.1075-1083
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• 2013

This paper describes an ultra-wideband (UWB) antenna that uses a ring resonator concept. The proposed antenna can operate in the entire UWB, and the IEEE 802.11a frequency band can be rejected by inserting a notch stub into the ring resonator. The experiment results indicate that the measured impedance bandwidth of the proposed antenna is 17.5 GHz (2.5 GHz to at least 20 GHz). The proposed UWB antenna has omnidirectional radiation patterns with a gain variation of 3 dBi (1 dBi to 4 dBi).

• Journal of information and communication convergence engineering
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• v.8 no.5
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• pp.498-501
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• 2010

In this paper, we extend ultra-wideband (UWB) single input single output (SISO) systems with a hybrid pulse amplitude and position modulation (PAPM) to single input multiple output (SIMO) systems using receive antenna diversity. The performance of a rake receive diversity combining scheme for UWB SIMO systems with a PAPM is examined in a log-normal multipath fading channel and also compared with that of a time-switched transmit diversity (TSTD) multiple input single output (MISO) system. It is seen that as the number of receive antennas increases, the receive diversity combining system improves the error performance. It is shown that the TSTD UWB MISO systems offer the performance equivalent to the receive diversity combining scheme for SIMO systems.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1350-1353
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• 2002

A new form of spread spectrum technique called the ultra wideband impulse radio (UWB-IR) system has drawn much attention for future high speed wireless communication services. In this paper, a new type of time hopping sequences constructed from multiple distinct m-sequences of the same order, is proposed for multiple access in the UWB-IR systems. Simulation results reveal that the proposed time hopping sequences achieve comparable or even better bit error rate performance than the ideal random sequences, and can be effectively applied in various multiple access situations.

• ETRI Journal
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• v.28 no.1
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• pp.95-98
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• 2006

In this letter, a novel M-ary code-selected direct sequence (DS) ultra-wideband (UWB) communication system is presented. Our purpose is to achieve a high data rate by an M-ary code-selected direct sequence bipolar pulse amplitude modulation (MCSDS-BPAM) scheme. In this system, a particular DS code sequence is selected by the $log_2M$/2 bits from the DS gold code set. This scheme can accomplish both a high data rate without increasing the system bandwidth or changing the pulse shape and improve the BER with an increase of modulation level M even at a lower signal-to-noise ratio (SNR). The receiver signal processing algorithm is given for an MCSDS-BPAM UWB system over an ideal AWGN channel and correlation receivers.

• ETRI Journal
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• v.29 no.4
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• pp.437-444
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• 2007

A CMOS frequency synthesizer block for multi-band orthogonal frequency division multiplexing ultra-wideband systems is proposed. The proposed frequency synthesizer adopts a double-conversion architecture for simplicity and to mitigate spur suppression requirements for out-of-band interferers in 2.4 and 5 GHz bands. Moreover, the frequency synthesizer can consist of the fewest nonlinear components, such as divide-by-Ns and a mixer with the proposed frequency plan, leading to the generation of less spurs. To evaluate the feasibility of the proposed idea, the frequency synthesizer block is implemented in 0.18-${\mu}m$ CMOS technology. The measured sideband suppression ratio is about 32 dBc, and the phase noise is -105 dBc/Hz at an offset of 1 MHz. The fabricated chip consumes 17.6 mA from a 1.8 V supply, and the die-area including pads is $0.9{\times}1.1\;mm^2$.

• Journal of electromagnetic engineering and science
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• v.9 no.4
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• pp.202-210
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• 2009

In this paper, we have analyzed the effect of interference between ultra-wideband(UWB) and intelligent transport systems(ITS). The maximum possible UWB emission power and minimum possible distance between UWB devices and ITS are found. In order to analyze the interference, we employ the Monte-Carlo(MC) method. We consider six situations, which are indoor office line-of-sight(LOS), indoor office non-line-of-sight(NLOS), indoor residential LOS, indoor residential NLOS, outdoor rural LOS, and outdoor rural NLOS environments. From the simulation results, it is confirmed that coexistence between UWB and ITS devices can be realized in accordance with the emission mask of 19.3 dB for indoor application or 19.3 dB for an image system. And in the outdoors, coexistence between UWB and ITS devices can be realized if the emission mask is at least 1.6 dB for vehicles' radar systems.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.49.4-49.4
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• 2018

We present measurement results of the fabricated ultra wideband corrugated horn for the planned ASTE band7+8 receiver. Return loss and vector beam pattern measurements were carried out over 275-500 GHz frequency range. Hardware set-ups for these measurements are described as well as beam measurement data are compared with such design criteria as beam width, phase curvature and cross-polarization. We discuss the impact of these beam measurement results to the aperture efficiency of the proposed 2-mirror receiver optics for the ASTE telescope.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.229-233
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• 2003

In this paper we theoretically analyze the probability of error for M-ary pulse position modulation (PPM) ultra-wideband (UWB) multiple access system using Gaussian monopulse. The optimum detection of UWB signals using M-ary orthogonal PPM in additive white Gaussian noise (AWGN) and multiple access interference (MAI) is considered, then receiver signal to noise power ratio (SNR) and upper bound fur the bit error rate (BER) are derived. Numerical results considering some practical parameters are presented.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.1
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• pp.41-48
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• 2004

In this paper, we analyzed channel performance of PPM modulated UWB communication system in indoor radio fading environment that consider amplitude characteristic of channel. Fading channel considered various channel environments by fading index m utilizing Nakagami-m distribution model with data through an UBW radio signal experiment that announced in existing. Also, we improved performance of system that it is decreased in fading environment employing convolution encoding techniques.