• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.3
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• pp.32-39
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• 2009

In this paper, system optimization design technique of an impulse ground penetrating image radar (GPIR) in time domain is proposed to improve depth resolution of the system. For the purpose, time domain analysis method of key components such as impulse generator and UWB antenna is explained and by simulation, parameters of each component are determined. In particular, by standardizing the impulse signal, spectrum efficiency of a radiated impulse signal is improved and a U-shaped planar dipole antenna for a UWB antenna is developed. By equipping a parabolic metal reflector with the proposed antenna, external noise is prevented and the ability of radiating an input impulse into ground is improved. In addition, to remove ringing effect of the propose antenna which causes serious degradation of the system performance, resistors are loaded at the edge of the antenna and then Tx and Rx UWB antennas are optimized by simulation in time domain. For images of targets buried under the ground migration technique is applied and influence of tough ground surface on distortion of received impulse signals is reduced using technique of noise and signal distortion reduction in time domain and its time resolution is enhanced. To verify the design optimization procedure, a prototype of an GPIR and an artificial test field are made. Measurement results show that the resolution of the system designed is as good as that of a theoretical model.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.5
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• pp.103-115
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• 2012

In this paper, design and performance evaluation of Tapered Slot Antenna for IR-UWB which propagates impulse radio is performed. TSA which has directional characteristic in UWB band should have low radiation loss and minimized impulse radiation distortion. In order to achieve these objectives, the paper designed wide band Impedance transformer and microstrip-slotline transit region structured TSA feeder line. By using the fabricated TSA, the radiation pattern was measured in the radio anechoic chamber. Pulse fidelity and distortion equation was induced to evaluate time domain characteristics according to the impulse radiation. Pulse fidelity of Impulse radiation show favorable results more than 93% within ${\pm}30^{\circ}$ beam width.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.14 no.3
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• pp.263-279
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• 1989

In part-1 of this paper, the error rate equations of digitally modulated signals transmitted though the Gaussian/Impulsive noise channel have been derived. Using the derived equations for the error probabilities of ASK, QAM, CPSK, DPSK, FSK and MSK signals, the error rate performances of digital modulation systems have been evaluated and represented in the figures as the functions of carrier-to-noise power ratio(CNR), impulsive index, and the ration of Gaussian noise power component to impulsive noise power component. The results are shown in graphs to known how much impulsive noise effects on digital signals than Gaussian noise.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.7
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• pp.1115-1121
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• 2001

In this paper, we analyzed the performance of GFSK system that presence fading effect in indoor radio communication environments and impulsive electromagnetic noise from electronic equipments then we applied the Truncated Type- II Hybrid ARQ scheme to make satisfied in data transmission service. As a result, the system was influenced by fading and impulsive electromagnetic noise. Especially, the system was much degraded by high occurrence frequency and amplitude of impulsive electromagnetic noise than fading which has direct frequency. By adopting the Truncated Type-II hybrid ARQ technique we can also obtained the performance improvement in the low signal power(20 dB) arid over 24 dB in strong impulsive electromagnetic noise environment which is occurred error floor and terribly influenced by the system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.5
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• pp.1251-1256
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• 2010

In the transmitting process of image signal processing system, there are several different causes of degradation that have been occuring. The main cause of degradation is attributed to the noise. The most representive method of removing noise of image, which is caused by impulse noise environment, is using the SM filter. At edge, the filter has a special feature which has a tendency to decrease. As a result, we proposed a nonlinear filter using the form of mask and the probability of the impulse noise to restore the image considering edge quality in the impulse noise environment. And through the simulation, we compared with the existings and capabilities.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.959-962
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• 2012

In the process of image acquisition, transmission and storage, image degradation occurs due to various reason, the mainly reason is noise. To restore basic methods used images of impulse noise pollution by SM, AF, CWMF. In this paper, using the modified filter to remove impulse noise. The method consists of detection and noise filtering of the noise signal. For a non-noise signal is intact, the noise signal is filtered according to the algorithm. And then through the simulation is compared with known basic methods, with PSNR as judged by reference.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.7
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• pp.1725-1731
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• 2013

Recently, as industrial society is developed as high digital information age, image processing is used in a variety of areas. However, image deterioration is still occurred by several noises in the data processing, and different kinds of researches are in progress for noise removal. Therefore, this paper limited the modified median filter by using standard deviation to removes impulse noise. The proposed algorithms divided into noise detection and noise removal, the noise free pixel is maintained, the noise pixel filtered. And it was compared with the existing methods for its objective judgment, using PSNR(peak signal to noise ratio) as standard criteria.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2002.11a
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• pp.31-35
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• 2002

본 논문에서는 DVB-T 표준안의 모든 동작모드를 지원하며 임펄스 잡음 제거, 안테나 diversity 수신, 향상된 채널추정방법을 적용한 유럽향 디지털 TV 수신용 채널 칩셋의 설계에 관한 내용이다. 설계된 칩은 여러 개의 구성 블럭으로 구성되어있는데 여기에는 여러 가지의 향상된 알고리즘과 설계 아키텍쳐가 사용되었다. 가정용 가전기기들이 발생시키는 일정주기의 임펄스 잡음을 제거하기 위하여 임펄스 잡음 제거 블록을 AGC뒤에 사용하였다. 동기부는 대략적 주파수동기, 미세 주파수동기, 대략적 타이밍동기, 미세 타이밍 동기 등으로 이루어져 있으며 본 설계의 주파수 보상 영역은 $\pm$280Khz, 타이밍 보상 영역은 $\pm$500ppm이다. 파일럿 신호를 이용하여 채널추정과 보상을 수행하며 기존의 선형 보간기법과 함께 4개의 파일럿 신호를 이용한 보간기법을 사용하여 이동수신환경에 대응할 수 있도록 하였다. 이와 함에 수신성능을 개선할 수 있다고 알려진 안테나 diversity 기능을 채용하여 고정 및 이동 수신시의 수신성능을 향상시켰다. 안테나 diversity를 위해서 2개 이상의 수신 칩이 사용되며 이를 위해서 본 설계에서는 MRC(Maximum Ratio Combining)알고리즘을 사용하였다 본 설계는 5층 메탈 0.18um 공정을 사용하였으며 2.7Mbit 의 메모리 소자를 포함하여 대략 300 만 게이트의 회로크기를 갖으며 100 핀 PQFP로 제작되었다. 본 논문에서는 설계된 회로의 각 블록별 기능에 대한 설명과 함께 시뮬레이션 결과와 ASIC설계결과를 기술하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.12
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• pp.1365-1372
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• 2012

This paper presents a methodology to accurately evaluate the spectral components of impulse signals which are delivered from an impulse generator through the measurement system. The complicated terms for uncertainty measurement of impulse spectrum amplitude and their analysis methods and experimental results are discussed. The expanded uncertainty of the impulse spectrum measurement is 0.015, which is believed to be the best domestic measurement capability and comparable to those of world class.

• Journal of the Institute of Convergence Signal Processing
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• v.5 no.2
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• pp.151-158
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• 2004

In this paper, an inverse filtering technique for the digital filter model is proposed. This technique enables us to obtain a stable non-causal m inverse filter by transforming (approximating) it to a causal stable inverse system. In practice, a causal FIR approximation to this inverse filter is proposed. It can be shown that the impulse response of the inverse filter for all-pass systems is simply the mirror image of the impulse response for the system. Specially, due to this symmetric property of the impulse response of all-pass systems, the proposed technique is more useful for all-pass systems than other systems. In order to illustrate the proposed inverse filtering technique, four examples are presented. Two of them are for all-pass filters. The other two examples are for IIR and FIR filters. Also, computer simulations demonstrate that the proposed technique works very well.