• Title, Summary, Keyword: Spectrum Calculation

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Calculation of Spectral Efficiency for Estimating Spectrum Requirements of IMT-Advanced in Korean Mobile Communication Environments

  • Chung, Woo-Ghee;Lim, Eun-Taek;Yook, Jong-Gwan;Park, Han-Kyu
    • ETRI Journal
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    • v.29 no.2
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    • pp.153-161
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    • 2007
  • In this paper, we analyze the algorithm of the methodology developed by ITU for the calculation of spectrum requirements of IMT-Advanced. We propose an approach to estimate user density using traffic statistics, and to estimate spectrum efficiencies using carrier-to-interference ratio distribution and capacity theory as well as experimental data under Korean mobile communication environments. We calculate the IMT-Advanced spectrum requirements based on the user density and spectral efficiencies acquired from the new method. In the case of spectral efficiency using higher modulation and coding schemes, the spectrum requirement of IMT-Advanced is approximately 2700 MHz. When applying a $2{\times}2$ multiple-input multiple-output (MIMO) antenna system, it is approximately 1500 MHz; when applying a $4{\times}4$ MIMO antenna system, it is approximately 1050 MHz. Considering that the development of new technology will increase spectrum efficiency in the future, the spectrum requirement of IMT-Advanced in the Korean mobile communication environment is expected to be approximately 1 GHz bandwidth.

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Parametric Modelling of Coupled System (커플시스템의 파라메트릭 모델링)

  • Yoon, Moon-Chul;Kim, Jong-Do;Kim, Byung-Tak
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.5 no.3
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    • pp.43-50
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    • 2006
  • In this successive study, the analytical realization of coupled system was introduced using the times series identification and spectrum analysis, which was compared with conventional FFT spectrum. Also, the numerical responses of second order system, which is coupled, were solved using the numerical calculation of Runge-Kutta Gill method. After numerical analysis, the displacement, velocity and acceleration were acquired. Among them, the response of displacement was used for the analysis of time series spectrum. Among several time series, the ARMAX algorithm was proved to be appropriate for the spectrum analysis of the coupled system. Using the separated response of 1st and 2nd mode, the mode was calculated separately. And the responses of mixed modes were also analyzed for calculation of the mixed modes in the coupled system.

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Efficient Seismic Analysis of Bridge by Single Mode Spectrum Analysis Method (단일모드 스펙트럼해석법에 의한 교량의 효율적 내진해석)

  • 박윤봉;국무성;유승운;김선훈
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.487-494
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    • 2003
  • Recently it is used seismic analysis like single mode spectrum analysis, multi mode spectrum analysis and time history analysis in Korea. Because bridges are not special form of them but regular and simple form of them in our country, we must develope seismic analysis program of bridge based on single nude spectrum analysis. The program developed by this study reduces a Quantity and a time of calculation compared to SAP90 and gives accurate answers without errors. In the case of commercial program if we look for seismic load(P/sub e/(x)), we must increase the number of node and the larger the number of node the more a quantity and a time of calculation. But this program is exactly solved with basic node compared to commercial program.

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An Empirical Study on Improving the Spectrum Usage Fee System (전파사용료 제도의 합리적 개선방안에 관한 연구)

  • Lee, Kun-Chang;Lee, Seung-Jin
    • Korean Management Science Review
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    • v.23 no.3
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    • pp.225-242
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    • 2006
  • The Spectrum Usage Fee System which has been introduced and enforced since 1993 has had a great role for effective use of the radio frequency resources and the promotion of radio wave industry. However, the current system has been criticized due to several drawbacks. For example, broadcasting stations and national institutions are exempted whereas the overdue utility rate on some frequency has been imposed. So there has been rising the questions on whether the principles of fair imposition are broken. Another problem regarding the current system is that how to calculate the fee is too much complicated, and it needs to be revised into a simpler and clearer formulation. In this regard, this study intends to propose a new calculation framework for the radio spectrum usage fee and then prove its validity empirically on the basis of real data gathered from MIC and focus group interview.

Investigation of the Dynamic Properties of Railway Tracks using a Model for Calculation of Generation of Wheel/Rail Noise

  • Koh, Hyo-In;Nordborg, Anders
    • International Journal of Railway
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    • v.7 no.4
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    • pp.109-116
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    • 2014
  • For optimization of a low-noise track system, rail vibration and noise radiation needs to be investigated. The main influencing parameters for the noise radiation and the quantitative results of every track system can be obtained using a calculation model of generation and radiation of railway noise. This kind of model includes contact modeling and the calculation model of the dynamic properties of the wheel and the rail. This study used a nonlinear wheel/rail interaction model in the time domain to investigate the excitation of the rolling noise. Wheel/rail response is determined by time integrating Green's function of the rail together with force impulses from the wheel/rail contact. This model and the results of the study can be used for supporting calculation with the conventional model by an addition of the contributions due to nonlinearities to the roughness spectrum.

Spectrum Requirements for the Future Development of IMT-2000 and Systems beyond IMT-2000 (4세대 이동통신 서비스 주파수 소요량에 관한 연구)

  • Chung Woo-Ghee;Yoon Hyun-Goo;Lim Jae-Woo;Yook Jong-Gwan;Park Han-Kyu
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.17 no.2
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    • pp.110-116
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    • 2006
  • In this paper the algorithm of a methodology for the calculation of spectrum requirements was implemented. As well, the influence of traffic distribution ratio among radio access technology groups, spectral efficiency, and flexible spectrum usage(FSU) margin was analyzed in terms of the spectrum requirements, with a view toward for future development of IMT-2000 and systems beyond IMT-2000. The ratio of the spectrum requirement to the traffic distribution ratio is approximately $1\;GHz/20\;\%$, and the spectrum requirement varies from 5 to 9 GHz. As the FSU margin increases by 1.0 dB, the total spectrum requirement decreases by 0.9 dB. The required spectrum for the market input parameter, ${\rho}=0.5$ is 801.63 MHz, while the required spectrum for ${\rho}=1.0$ is 6295.4 MHz. It can be concluded that the market input parameter is the most effective parameter in the calculation of spectrum requirements.

Finding Alternative Solutions and Analyzing Spectrum Policy Cost on Spectrum Usage (전파사용 기반의 전파정책성 비용제도 분석 및 대안의 결정)

  • Ahn, Choon-Soo;Lee, Dong-Hyung;Youm, Se-Kyoung
    • Journal of the Society of Korea Industrial and Systems Engineering
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    • v.35 no.2
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    • pp.181-188
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    • 2012
  • The fee system on spectrum usage is a usage fee that is charged for using spectrum provided by a wireless tower, and is used for management and promotion of the waves. The current fee system for spectrum usage in South Korea has faced many problems, such as complex calculation for fees, unjustified charges, unfairness in cost sharing among providers, and general inefficiency of operation. This study focuses on comparison of fee systems for spectrum usage of South Korea and other foreign countries, extraction of the root causes and problems by case analyses, and recommendation for better solutions to make a reasonable fee system for spectrum usage. The result of this study can be used as a solution to render spectrum usage more effective.

Gamma spectrum denoising method based on improved wavelet threshold

  • Xie, Bo;Xiong, Zhangqiang;Wang, Zhijian;Zhang, Lijiao;Zhang, Dazhou;Li, Fusheng
    • Nuclear Engineering and Technology
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    • v.52 no.8
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    • pp.1771-1776
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    • 2020
  • Adverse effects in the measured gamma spectrum caused by radioactive statistical fluctuations, gamma ray scattering, and electronic noise can be reduced by energy spectrum denoising. Wavelet threshold denoising can be used to perform multi-scale and multi-resolution analysis on noisy signals with small root mean square errors and high signal-to-noise ratios. However, in traditional wavelet threshold denoising methods, there are signal oscillations in hard threshold denoising and constant deviations in soft threshold denoising. An improved wavelet threshold calculation method and threshold processing function are proposed in this paper. The improved threshold calculation method takes into account the influence of the number of wavelet decomposition layers and reduces the deviation caused by the inaccuracy of the threshold. The improved threshold processing function can be continuously guided, which solves the discontinuity of the traditional hard threshold function, avoids the constant deviation caused by the traditional soft threshold method. The examples show that the proposed method can accurately denoise and preserves the characteristic signals well in the gamma energy spectrum.

An Effect of Energy Group Structure and Weighting Spectrum at the Resonance Energy Region of Iron on Neutron Shielding Calculation (철의 공명에너지 영역의 에너지군구조 및 가중스펙트럼이 중성자 차폐계산에 미치는 영향)

  • Jung-Do Kim;Yukio Ishiguro
    • Nuclear Engineering and Technology
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    • v.17 no.2
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    • pp.129-135
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    • 1985
  • Effects of differences between fine- and broad-group structures and spectrum as a weighting function at the resonance energy region of iron on a neutron shielding calculation were analyzed with the ANISN code and ENDF/B-IV data. The problems analyzed are the broad-group effect, the effect for variation of iron thickness, and the effect of problem-dependent weighting spectrum. In order to verify the group data and method used, a calculational benchmark was performed with the continuous-energy Monte Carlo code VIM. The result was compared with the ANISN calculations using the fine- and broad-group data.

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Mesurement of Evoked Otoacoustic Emission Latency Using Linear Prediction Coding Spectrum (선형예측부호화 스펙트럼을 이용한 유발이음청 방재파의 잠시측정)

  • An, Jung-Il;Choi, Jin-Young;Lee, Kuhn-Il
    • Journal of Biomedical Engineering Research
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    • v.12 no.3
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    • pp.185-190
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    • 1991
  • An automatized latency calculation method of an e-OAE(evoked otacoustic emission) is proposed. The e-OAE signal measured from a normal adult is averaged 1000 times to remove noises. This averaged signal is converted to digital signal and that is processed by IBM-AT computer for latency calculation. we separate the stimulated and the emitted signal on the time domain by a modified LPC (linear prediction coding) spectrum, and the latency is calculated by cross-correlation method. By proposed latency calculation method the latency is 7.9[ms] for normal adult. The performance of the proposed method is also compared with that of the auto-correlation and cross performance of the proposed method is also compared with that of the auto-correlation and cross-correlation method. The result show that the proposed method has same precision with the conventional methods and can automatically calculate latency without subjective observation.

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