• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.1
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• pp.37-42
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• 2000

The radio noise produced by corona discharge in high voltage transmission lines is one of the most important line design considerations. Therefore it is necessary for transmission line designers to pre-evaluate radio noise using prediction formulas or field test results. In this paper, more accurate and useful formulas for predicting radio noise during fair and foul weathers in high voltage AC transmission lines were proposed through comparison with the existing formulas. Also it was verified by comparing with the long-term measured data from operating lines that the proposed formulas are more accurate. The proposed prediction formulas are developed by the applications of nonlinear least squares optimization method to radio noise database collected from lines throughout the world.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.4
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• pp.651-658
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• 2017

This paper proposes an analysis method of performance degradation of antenna due to radio frequency interference between an antenna and adjacent noise sources using active scattering parameters. The radio frequency interference can be analyzed by the measured or simulated scattering parameters and by excited noise sources in the circuit as well. In this paper, a planar inverted-F antenna and a noise source are designed and fabricated to analyze radio frequency interference between the planar inverted-F antenna and noise source. The proposed analysis method uses active scattering parameters, of which verification is experimentally verified, and in simulation as well.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.461-464
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• 2004

The Broadcasting system is very important part of human life that preceding to people news, national plan, sport, drama, leisure and politics. The product of maded by broadcasting system conveyed the whole country by radio signal. A broadcasting station operate the broadcast product radio trial network in the mountain, Recently the height of new building, concrete structure is very large and higher than old one. Since one does or says, noise accur to radio and TV signal whole nation. In this study, Taejeon Sikjang mountain and Cheunan-Heuksung mountain where accured radio noise chosen as a sample, and analysis 3D simulation and plane check. Accordingly come to conclusion condition of noise occurred radio antenna.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.1
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• pp.110-115
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• 2000

A K-band GaAs MMIC receiver module has been developed using 0.15 ${\mu}{\textrm}{m}$ HEMT technology process. It incorporates two front end low noise amplifiers, a double balanced diode mixer, and filters. The RF input frequency ranges 20.1 to 21 GHz and the IF output 1.1 to 2 GHz. Test results show an overall conversion gain of more than 27 dB, and less than a 2.2 dB noise figure. The image-rejection ratio greater than 21 dB has been obtained. The isolation between RF and IF ports is better than 27 dB, and between LO and IF is more than 50 dB.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.4 no.1
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• pp.32-37
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• 1979

The corona noise level at the place 10m and the frequency 1MHz from the new 345KV transmission line is 72dB in the maximum rain-fall and 63dB due to the wet conductors. The synthesized corona noise level of all 3 phases dominantly depends on the phase which has maximum corona level among them. The measured characteristic of the variation with distance from the line coincided well with the theoretically calculated value in this paper. The corona noise level was the highest level in rainy weather or snow-fall. It takes a few hours, for the corona noise to be stable after a rain-fall or snow-fall. The measured value of the corona noise level corresponds quite well with the formula for the corona noise level revision. It was necessary to quantize S/N ratio into radio reception quality for the radio interference due to the transmission line. Some regulations for radio reception quality were defined through long term experiments and ratings by ITU, IEEE comittee, NHK in Japan and others. Fixing our own regulation about radio reception quality should be required.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.11A
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• pp.1105-1116
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• 2008

Cognitive radio is one of the most effective techniques to improve the spectrum utilization efficiency. To implement the cognitive radio, spectrum sensing is considered as the key functionality because only counting on it, can the secondary users identify the spectrum holes and utilize them efficiently without causing interference to primary users. Generally, there are several spectrum sensing methods; the most common and simplest method is energy detection. However, the conventional energy detection has some disadvantages, which are caused by noise, especially, uncertain noise power leads to degradation of energy detector. In this paper, to solve this problem, we proposed sliding window-based energy detection method which can devide the frequency band of primary signal and noise using sliding window to estimate the power of primary user without the noise effect and achieve the better performance. It can calculate the energy of primary user only and can detect the primary signal. The simulation result shows that our proposed method outperforms conventional one.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.65-68
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• 1999

In this paper the Wideband DS/CDMA system capacity variation is analyzed by the impact of imperfect sectorization and man-made noise, which is more predominant in urban area than thermal noise. In general man-made noise is increasing as the electronic machines are increasing nowadays. It shows that user capacity and cell radius variation are much sensitive by the man-made noise.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.2
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• pp.207-213
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• 1997

Measurements of the RF(Radio Frequency) noise spectrum from 30 MHz to 18 GHz have been conducted at 21 urban areas in Korea in 1994 and 1995. Statistical analysis of the data measured seasonally, day and night, at each different point has been performed. The results of the computer analysis on APD, NAD, and ACR[1] using GUI(Graphical User Interface) program show that the radio noise environments vary little in spring, summer, and winter, while the noise level increases a little in fall. In addition, the noise level of the night time shows a little higher than that of the day time.

• ETRI Journal
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• v.35 no.4
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• pp.644-654
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• 2013

In this paper, a signal detection scheme for cognitive radio (CR) based on the Bussgang theorem is proposed. The proposed scheme calculates the statistical difference between Gaussian noise and the primary user signal by applying the Bussgang theorem to the received signal. Therefore, the proposed scheme overcomes the noise uncertainty and gives scalable complexity according to the zero-memory nonlinear function for a mobile device. We also present the theoretical analysis on the detection threshold and the detection performance in the additive white Gaussian noise channel. The proposed detection scheme is evaluated by computer simulations based on the IEEE 802.22 standard for the wireless regional area network. Our results show that the proposed scheme is robust to the noise uncertainty and works well in a very low signal-to-noise ratio.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.4
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• pp.462-472
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• 1998

In this paper, considering the Rayleigh fading, the lognormal shadowing, and the man-made noise which is occurred in urban area randomly, the mobile radio channel and the radio propagations are analyzed. The system affected by the noise is compared to other modelings. The fading, shadowing, and background noise are wholly considered to evaluate the mobile radio propagation effectively. For N=0.000001, the outage probability in the absence of noise is $5.264{times}10^{-6}$, in the fading only $3.1796{times}10^{-4}$, and in the presence of noise $6.0{\times}10^{-3}$. The analysis with the presence of noise is very important for the performance evaluation of mobile radio system.