• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.549-552
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• 2000

본 논문에서는 주파수 영역 배열안테나의 계산량을 감소시키기 위한 센서링 부분적응 알고리듬을 제안한다. 제안한 알고리듬은 입력신호를 주파수 영역으로 변환한 후 CFAR(constant false alarm rate) 검파기법을 이용하여 간섭신호가 존재하는 주파수 대역을 찾아내고 이에 해당하는 가중치에 대해서만 적응 신호처리를 수행한다. 이때 CFAR 검파기의 오경보율은 출력신호의 전력 변화량을 이용하여 환경에 맞게 적응적으로 변화시켜서 최적 값으로 설정한다.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.25-28
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• 2000

In this paper, we choice multicarrier direct-sequence code division multiple access using bandwidth effectively in communication system. Because this system is based on DS-CDMA the same problem is raised. That is, the degradation of the performance is due to multiple access interference. To solve this problem, we proposed the blind adaptive receiver for MC DS-CDMA system. Simulation results show that the proposed blind receiver has more about 0.5(dB) value of SNR than conventional receiver.

• Proceedings of the Optical Society of Korea Conference
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• 2002.07a
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• pp.48-49
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• 2002

현재 세계의 통신업계들은 인터넷, 멀티미디어 서비스 등의 발전에 따라 폭발적인 전송 속도의 증가를 예측하고 있다. 대용량의 정보를 초고속으로 전달하기 위한 방법으로 각광 받고 있는 광통신은 사무실의 네트웍, 가정의 전자용품, 항공기내 정보시스템 구축, 인터넷 화상 통신 등에 이용되고 있다. 최근에는 플라스틱 광섬유(POF; plastic optical fiber)에 관한 연구가 활발히 이루어지고 있다. 기존의 구리 전선이 가지는 단점인 전자기적 간섭과 무거운 중량을 극복한 것이 유리 광섬유이다. (중략)

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.307-308
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• 2008

In this paper, we propose a mitigation method to reduce the effect of pilot interference at the wireless repeater. This improves the signal to interference ratio (SIR), and enables increased cell capacity and better bits error rates (BER) performance in the WCDMA systems. Simulation studies have been carried out to verify the proposed approach and we obtained promising results.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.821-824
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• 1999

In this article, as a way of pursuing high spectral efficiency and flexible cell planning, co-channel dual-polarization techniques are suggested for B-WLL applications. It provides a double down stream capacity compared with conventional scheme and also makes some flexibility in cell planning. In order to implement co-channel B-WLL system, some frequency plans, interference cancellation methods, and system block diagrams are presented here.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.235-237
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• 2004

The conductive noise which produced from the electric train affected signalling system. So, in order to investigate the influence about it, this paper presented measurement method and result of verification for electric train.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.6
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• pp.12-20
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• 2000

In this paper, we propose to use nonparametric detector for the PN code acquisition in DS/CDMA systems. Because the detector is nonparametric, Ive can decide the threshold of the detector without first haying to estimate the valiance of time-varying interference. We compare the proposed detector with the conventional detector by showing both analytic and simulation results. From these results, we can observe that the DS/CDMA system with the proposed detector have better performance than that with the conventional detector when the exact estimation of the interference variance is not possible.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.2
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• pp.51-59
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• 2023

The tracking radar system is installed and operated on the ground, ships, and aircraft, and requires a design to withstand electromagnetic interference with nearby electronic devices. In this case, radiation and immunity standards for cable connection must be satisfied to prevent malfunction of other equipment due to electromagnetic wave interference caused by cables connected to the tracking radar. The radiation standard must also be satisfied so that the electromagnetic wave noise generated and radiated from the tracking radar does not affect the peripheral device, so that the immunity standard for the electromagnetic wave emitted from the peripheral device must be satisfied. In this paper, we propose a design to satisfy MIL-STD-461G including CE, CS, RE, and RS, and explain design satisfaction through tests.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.3
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• pp.37-46
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• 2012

In RADAR and SONAR detection systems, noise environment can be classified into homogeneous and heterogeneous environment. Especially heterogeneous environments are modelled as target masking and clutter edge. Since the variability-index (VI) CFAR, a composed CFAR algorithm, dynamically selects one of the mean-level algorithms based on the VI and the MR (mean ratio) test, it is robust to various environments. However, the VI CFAR still suffers from lowered detection probabilities in heterogeneous environments. To overcome these problems, we propose an improved VI CFAR processor where TM (trimmed mean) CFAR and a sub-windowing technique are introduced to minimize the degradation of the detection probabilities appeared in heterogeneous environments. Computer simulation results show that the proposed method has the better performance in terms of detection probability and false alarm probability compared to the VI CFAR and single CFAR algorithms.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.1
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• pp.29-35
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• 2016

We have demonstrated a $Ti:LiNbO_3$ electro-optic electric-field sensors utilizing a $1{\times}2$ Y-fed balanced-bridge Mach-Zehnder interferometric (YBB-MZI) modulator which uses a 3-dB directional coupler at the output and dipole patch antenna. The operation and design were proved by the BPM simulation. A dc switching voltage of ~16.6 V and an extinction ratio of ~14.7 dB are observed at a wavelength of $1.3{\mu}m$. For a 20 dBm rf power, the minimum detectable electric-fields are ~1.12 V/m and ~3.3 V/m corresponding to a dynamic range of about ~22 dB and ~18 dB at frequencies 10 MHz and 50 MHz, respectively. The sensors exhibit almost linear response for the applied electric-field intensity from 0.29 V/m to 29.8 V/m.