• Title/Summary/Keyword: Reception Noise

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Improvement of Reception Noise During Formation Flight of Aircraft (항공기 편대 비행 중 수신 잡음 개선 연구)

  • Kwon, Jung-Hyuk;Seo, Hong-Eun;Lee, Wang-Sang
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.49 no.6
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    • pp.497-504
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    • 2021
  • This paper presents improvement of the reception noise suppression method during formation flights of aircraft. Since aircraft communication equipment is very important for flight mission and safety to perform the functions of internal/external communications, it is required to implement noise-free, clean communication quality, and transmitting/receiving functions. Therefore, the FTA (Fault Tree Analysis) analysis and failure search were performed on the reception noise, and the internal noise of the intercom that affected the reception noise and the none-transmition phenomenon was identified. We changed the multiple grounds of the intercom to a single ground and applied an improved method of filtering the DC Offset voltage. As a result, the voice quality of the communication system of the aircraft was improved through the reduction of the reception noise during formation flights, and it was verified by ground and flight tests.

The Error Rate Performance of digital Radio Signals in Diversity Reception (다이버시티 수신시의 제반 디지탈 신호의 오율특성)

  • 오창헌;공병옥;조성준
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.16 no.6
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    • pp.489-497
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    • 1991
  • The error rate pquations of digital radio signals transmitted throught the Nakagami's m-distribution fading channel have been both for nondiversity reception and for diversity reception cases in the environmment of Gaussin noise. Using the derived equation. erro rate performance has been evaluated and represented in figures as a function of carrier to noise ratio, fading figure, and the power correlation coefficient between two diversity branches. By comparing the diversity reception case with nondiversity reception case. We could measure the amount of error rate performance improvenment of digital radiosignals in fanding enviroment.

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Performance Analysis of QPSK and QDPSK Signals with Diversity Reception and Coding Techniques in Fading Plus Impulsive Noise Environments (임펄스 잡음과 페이딩이 함께 존재하는 환경에서 다이버시티 수신 기법과 부호화 기법을 채용하는 QPSK 및 QDPSK 신호의 성능 해석)

  • Leem, Kill-Yong;Cho, Sung-Joon;Lee, Jin
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.5 no.4
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    • pp.3-17
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    • 1994
  • The error probability of QPSK and DPSK signals with diversity reception technique in m-distribution fading plus impulsive noise environments has been derived and the error probability is evaluated and compared with that in Gaussian noise environment. The error performance degrades as impulsive noise becomes strong and degree of degradation of signal performance in QDPSK signal is larger than that in QPSK signal. The diversity reception technique can improve the error performance not only in fading plus Gaussian noise environment but in fading plus impulsive noise environment. When diversity reception technique is used, the improvement of error performance attains about 10dB to 15dB in terms of CNR as compared with that in non diversity reception. Among diversity techniques the maximal ratio combining is must effective. When diversity reception and coding techniques are used together in impulsive noise plus Rayleigh fading environments, the improvement of error performance attains about 12dB to 15dB in terms of CNR as compared with that of only diversity reception technique case and the improvement of error perform- ance in RS coding attains about 2dB in terms of CNR as compared with that of BCH coding case.

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A Comparison of C/No Estimation Techniques for Commercial GPS Receivers under Jamming Environments (전파방해환경에서 상용 GPS 수신기의 C/No 추정기법 성능분석)

  • Baek, Jeehyeon;Yoo, Seungsoo;Kim, Sun Yong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.11
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    • pp.973-975
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    • 2013
  • In this paper, the carrier-to-noise power ratio estimation performances for commercial GPS receiver are shown by simulation and are analyzed under weak signal reception, high sensitivity signal reception, and the matched spectrum jamming signal reception environments.

Equalization Digital On-Channel Repeater Part 2 : Field Test Results (등화형 디지털 동일 채널 중계기 Part 2 : 필드 테스트 결과)

  • Park Sung Ik;Lee Yong-Tae;Eum Homin;Seo Jae Hyun;Kim Heung Mook;Kim Seung Won;Lee Soo-In
    • Journal of Broadcast Engineering
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    • v.10 no.2
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    • pp.221-237
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    • 2005
  • This paper presents and analyzes field test results of Equalization Digital On-Channel Repeater (EDOCR) using ATSC(Advanced Television Systems Committee) terrestrial digital TV broadcasting system. In the field test, according to EDOCR On/Off, types of antennas and receivers we measured reception possibility, C/N(Carrier to Noise Ratio), reception power, noise and input margin at each test point. By the field test results, the reception rate of the receiver manufactured in 2004 was $33\%$ when EDOCR is off and directional antenna is used. However, the reception rate was $100\%$ when EDOCR is on. In addition, the noise margin, which determines reception quality was increased at least 6 dB, so that it is capable of constructing SFN(Single Frequency Network) using the EDOCR.

A Study on the Radio Interference due to the Corona Noise of 345 KV Transmission Line (345KV 송전선에 의한 CORONA 잡음 전파장해 연구)

  • 최기호
    • 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.

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A Study on the Improvement of BFSK Signal Performance in Mobile Radio Channel with Impulsive Noise (임펄스 잡음이 존재하는 이동통신로 환경에서 BFSK 신호의 성능 개선에 관한 연구)

  • Leem, Kill-Yong;Ko, Bong-Jin;Cho, Sung-Joon;Lee, Jin
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.7 no.3
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    • pp.230-238
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    • 1996
  • In this paper, the performance improvement of BFSK signal by using diversity reception and coding technique in Rayleigh fading and impulsive noise environments has been evaluated and compared with that in Gaussian noise environment. It is found that as the CNR increases, BFSK signal performance shows an error floor regardless of impulsive noise effects in Rayleigh fading environment. Also diversity reception technique can improve the error performance not only in a Gaussian noise environment but also in a fading and impulsive noise environment. When diversity reception and coding techniques are used together in impulsive noise and Rayleigh fading environment, the improvement of error performance becomes about 11[dB] in terms of CNR as compared with that of only coding technique is applied.

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Analysis on DTV Indoor Reception Environments (디지털 TV 실내수신 환경 분석)

  • Suh, Young-Woo;You, Ho-Jin;Park, Min-Ho;Park, Joon-Sung;Kim, Gyu-Young;Seo, Jong-Soo
    • Journal of Broadcast Engineering
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    • v.13 no.5
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    • pp.636-650
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    • 2008
  • DTV has a great advantage as compared to Analog TV in picture quality under low reception field strength. Various high quality tuners have been developed to result in much smaller Noise Figure of the receivers and many trials for receiving DTV signal through indoor antenna. In this paper, results of intensive field tests on the indoor reception of DTV are presented. Tests were carried out around Seoul-Gyeonggi Metropolitan area. Commercial directional and omni-directional antennas and 5th generation receiver were used for reception availability tests. The effects of heights, locations, and types of the house as well as the distance to the transmitter on the reception performances are analyzed. Our test results will be applied to improve the indoor reception environment of DTV.

Distributed Translator Part 3: Field Test Results (분산 중계기 Part 3: 필드 테스트 결과)

  • Park, Sung-Ik;Seo, Jae-Hyun;Eum, Ho-Min;Lee, Yong-Hoon;Kim, Heung-Mook
    • Journal of Broadcast Engineering
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    • v.15 no.1
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    • pp.40-51
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    • 2010
  • This paper presents and analyzes field test results of distributed translator (DTxR) for distributed frequency network (DFN) in the ATSC (Advanced Television Systems Committee) terrestrial digital TV broadcasting system. In the field test, according to types of antennas and receivers in areas where are overlapped by two DTxRs' coverage, we measured reception power, noise margin reception possibility, and ease of reception at each test point. By the field test results, when two DTxRs are on, reception power and noise margin are increased than when one DTxR is on. However, reception rate and ease of reception are similar or increased according to types of receivers.

Design and Fabrication of An LNA for The Reception of The Ku-Band Satellite Broadcast Signals (Ku-대역 위성 방송 수신 시스템을 위한 저잡음 증폭기의 설계 및 제작)

  • 주지한;이석곤;전병태;안병철
    • Proceedings of the IEEK Conference
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    • 2002.06a
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    • pp.451-454
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    • 2002
  • In this paper, a low-noise amplifier is designed and fabricated using the HJFET for the reception of the Ku-band satellite broadcast signals. The optimum input and output reflection coefficients of each amplifier stage are obtained by the trade-off between the stable gain and the noise figure circle. The amplifier performance is simulated and optimized using a microwave CAD software. The designed amplifier is fabricated and tested. Results of the test show a gain of 17.0 dB, a gain flatness of less than $\pm$2.BdB, the noise figure of less than 1.0 dB, and the input and output reflection coefficient of less than -10 dB.

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