• Title/Summary/Keyword: 시스템 성능

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A Study on Performance Analysis for Design of Terminal Server (터미널 서버의 설계를 위한 성능 분석에 관한 연구)

  • 최창수;이상훈;강준길
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.17 no.8
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    • pp.779-788
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    • 1992
  • The Input /output (I /0) subsystem is often the bottleneck in high performance computer system. Generally, system performance evaluation models were enhanced to include the effect of the I/0 system. In this paper, we modeled the terminal servers which are Indispensable devices In distribution of computer resources. We use M /M /1 Queueing model for find out the point of the system performance FIFO buffer sizes In the terminal server arc the Important fanctions of the system design and could be effected to the overall system functions. We have proposed the of optimal buffer sizes in the model of terminal server for increasing the system performance. We analizing the vatting time for terruanl server using Queueing model. and We find out the reference model result from simulation.

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Performance Analysis of GFSK Systems by Impulsive Electromagnetic Noise in Indoor Radio Fading Channel Environment (실내 무선 페이딩 채널 환경에서 임펄스성 전자간섭파에 의한 GFSK시스템의 성능 분석)

  • 이양선;김지웅;강희조
    • 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.

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A Study on the performance of coded Multi-carrier Code Division Multiple Access communication system in Rician Fading channel (Rician 페이딩채널상의 부호화 MC-CDMA시스템 성능에 관한 연구)

  • 고연화;이정재;최삼길
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.2 no.3
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    • pp.309-315
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    • 1998
  • This paper is analyzed the performance of coded MC-CDMA system using the multi-carrier with narrow band that is suggested to solve ISI and ICI of DS-CDMA system. In this paper, considered channel model is indoor mobile radio communication environment with Rician fading distribution and fading of multi-carrier have mutual independent characteristics. For the performance analysis of MC-CDMA system, first, bit error probability of uncoded system is simulated in the reverse and forward Rician channels. And then, it is simulated that bit error probability of coded MC-CDMA system for users, multicarriers and SNR, using (7,4) Hamming code, (15,7) BCH code and 1/2-convolutional code with 7 constraint length.

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Performance of M-ary OSTBC MIMO System (M-ary OSTBC MIMO 시스템의 성능 연구)

  • Hong, Young-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.9
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    • pp.6269-6273
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    • 2015
  • Performance of the Alamouti algorithm based M-ary $2{\times}N$ OSTBC(Orthogonal Space Time Block Coded) MIMO(Multi Input Multi Output) system has been simulated varying two main parameters - the number of constellation(M), and the number of receiving antennas(N). Computer simulation has also been carried out using Matlab software for performance comparison between $2{\times}N$ MIMO and MRC(Maximal Ratio Combining) diversity antenna system to evaluate the degree of enhancement achieved through the use of Alamouti $2{\times}N$ MIMO. Under 10 dB EbNo QPSK scenario, $2{\times}1$ MIMO brought 4.2 dB BER improvement over single antenna system and $2{\times}2$ MIMO resulted in 7.4 dB BER improvement over $1{\times}2$ MRC.

Performance Evaluation of Time Hopping Binary PPM Impulse Radio System according to Interference Environment (간섭 환경에 따른 TH Binary PPM IR 시스템의 성능 평가)

  • Lee, Yang-Sun;Kang, Heau-Jo
    • Journal of Advanced Navigation Technology
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    • v.6 no.4
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    • pp.318-325
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    • 2002
  • In this paper, the effects of the interference environments on the performance of the time hopping(TH) binary PPM impulse radio(IR) system are presented. Based on the monocycle pulse available within the frequency of 3.1~10.6 GHz permitted for application by FCC, a PPM-modulated TH IR system simulator was designed and followed by the analysis of the monocycle pulse characteristics as well as the system performance. Particularly for the evaluation of the system performance, the multiple access interference and the narrowband system interference signals were considered as the interference signals. Since the narrowband system interference signal has very narrow bandwidth and very large amplitude compared with those of IR system, the analysis of the IR system performance was implemented by considering the interference power and band fraction ratio of the narrowband interference signal.

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Performance Evaluation of STBC OFDM Systems using Channel Information (채널정보를 이용한 STBC OFDM 시스템의 성능 분석)

  • Choi, Seung-Kuk
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.2
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    • pp.246-252
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    • 2012
  • STBC is a technique where a multiple antenna signals are transmitted. With this technique, antenna diversity can be achieved. The performance of STBC OFDM system using pilot symbol for the channel estimation is analyzed. IEEE 802.16e standards suggest that the BER performance of STBC system can be improved using channel state information. Pilot symbol is used for the channel estimation in OFDM systems. However, imperfect channel estimates in this systems degrade the performance. The performance of this STBC OFDM systems using channel state information, gauged by the average bit error rate, is analyzed considering the channel estimation error.

The Performance Analyparkof Bandlimited WCDMA Systems (대역이 제한된 광대역 코드분할 다중화 시스템의 성능 분석)

  • Kim, Young-Sam;Park, Joong-Hoo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.4A
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    • pp.193-199
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    • 2003
  • In this paper, the performance of uplink WCDMA systems was analyzed using the SGA (Standard Gaussian Approximation) method and the SIGA(Simplified Improved Gaussian Approximation) method adopted for the performance analysis in conventional DS-CDMA systems. The performance of bandlimited WCDMA systems was analyzed using the SGA and SIGA method, and computer simulations were performed in AWGN environments having multiple access interference. It was shown that the performance analysis of uplink bandlimited WCDMA systems using the SIGa method may be very efficient through various computer simulations with verying spreading factors, roll-off factors, and signal-to-noise ratios.

Study on Memory Performance Improvement based on Machine Learning (머신러닝 기반 메모리 성능 개선 연구)

  • Cho, Doosan
    • The Journal of the Convergence on Culture Technology
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    • v.7 no.1
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    • pp.615-619
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    • 2021
  • This study focuses on memory systems that are optimized to increase performance and energy efficiency in many embedded systems such as IoT, cloud computing, and edge computing, and proposes a performance improvement technique. The proposed technique improves memory system performance based on machine learning algorithms that are widely used in many applications. The machine learning technique can be used for various applications through supervised learning, and can be applied to a data classification task used in improving memory system performance. Data classification based on highly accurate machine learning techniques enables data to be appropriately arranged according to data usage patterns, thereby improving overall system performance.

Optimum parameters of 3D integral imaging system (3차원 집적 영상 시스템의 최적 파라미터)

  • Cho, Myungjin;Lee, Byonggook
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • pp.1019-1022
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    • 2012
  • Integral imaging is a promising technology for 3D imaging and display. Many parameters affect the performance of 3D integral imaging systems. Enhanced system performance is acquired by optimization of these system parameters with respect to defined performance metrics. In this paper, we present an approach to optimize the performance of 3D integral imaging system in terms of performance metrics under fixed resource constraints. In this analysis, system parameters such as lens numerical aperture, pitch between image sensors, the number of image sensors, the pixel size, and the number of pixels are determined to optimize performance metrics. Wave optics is utilized to describe the imaging process.

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Performance of a Hybrid DS/SFH Spread Spectrum System over Nakagami Fading Channel in the Presence of Multiple Tone Jamming (다중 톤 방해신호가 존재하는 나카가미 페이딩 전송로에서 DS/SFH 복합 확산대역 시스템의 성능분석)

  • Byun, Woo-Sub;Sung, Koeng-Mo
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.36S no.8
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    • pp.8-16
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    • 1999
  • In this paper, the performance of a hybrid DS/SFH-SS(direct-sequence/slow-frequency-hopped spread-spectrum) system with coherent BPSK modulation over Nakagami fading channel in the presence of multiple tone jamming is analyzed. Because the Nakagami m-distribution can describe not only Rayleigh fading but also more general fluctuations involving a specular component by adjusting the value of the fading index m. It is known that for m=1 corresponds to Rayleigh fading, for $1/2{\le}m{\le}1$ corresponds to the worst case fading condition, for m>1 corresponds to Rician fading, and for $m{\to}{\infty}$ corresponds to the nonfading condition. The bit error probability is derived over Nakagami model and numerical evaluations are presented for some combinations of system parameters. The results show that as m increases, the bit error probability is better. Also, at a low JSR(jamming-to-signal power ratio), a pure DS-SS system can achieve lower bit error probability than a hybrid DS/SFH-SS system. But at a high JSR, a hybrid DS/SFH-SS system is shown to be superior to a pure DS-SS system. Therefore, it is demonstrated that without increasing the total system bandwidth, the performance of a hybrid DS/SFH-SS is superior to that of a pure DS-SS system in the presence of multiple tone jamming.

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