• Title/Summary/Keyword: 다중 입출력 시스템

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Efficient Schemes for Enhancing Performance of Disk I/O in Ring based NUMA Systems (링 구조 NUMA 시스템에서 디스크 입출력의 성능 향상을 위한 효율적인 방안)

  • Kim, Cheol-Hong;Kim, Myeong-Ju;Jang, Seong-Tae;Eom, Seong-Yong;Jeon, Ju-Sik
    • Journal of KIISE:Computer Systems and Theory
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    • v.28 no.3
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    • pp.134-143
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    • 2001
  • NUMA 구조 다중 프로세서 시스템에서는 상호 연결망으로서의 버스의 제약을 극복하기 위해 지점간 링크를 이용한 링 구조가 제안되었다. 링 구조 NUMA 시스템에서, 전송이 페이지 단위(2K 바이트 이상)로 이루어지는 디스크 입출력 요구는 지점간 링크에 대한 오랜 접근을 요구하여 지점간 링크의 트래픽을 증가시키는 원인으로 작용한다. 본 논문에서는 지점간 링크의 트래픽을 줄이기 위한 방안으로 입출력 전용 채널을 사용하는 세 가지 디스크 입출력 구조를 제시한다. 제시되는 디스크 입출력 구조를 사용하는 시스템은 디스크 입출력 요구로 인한 지점간 링크의 접근을 없앰으로써 기존 시스템에 비해 트랜잭션의 수행시간을 줄일 수 있다는 장점이 있다. 중앙집중형, 병렬형, 분산형의 세 가지 디스크 입출력 구조를 설계하기 위한 고려 사항과 구현 비용 등을 생각해 본 후, 노드수, 원격 디스크 접근 확률, 디스크 입출력 전송 데이터 크기 등을 달리한 여러 시스템 환경에서의 각 구조의 성능을 비교, 분석해 본다.

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Channel Selective Relay-based Transmission System for Broadband Wireless Communications (광대역 무선 이동 통신을 위한 채널 선택적 릴레이 기반 전송 시스템)

  • Won, Hui-Chul
    • Journal of Korea Society of Industrial Information Systems
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    • v.14 no.4
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    • pp.8-15
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    • 2009
  • Relay-assisted multi-input multi-output (MIMO) technique has become a promising candidate for next generation broadband wireless communications for high speed access. In this paper, we propose channel selective relay-based MIMO transmission system. The performance of relay-based system can be improved by using the subcarriers selectively based on the channel condition between relay and mobile station. Simulation results show that the proposed relay-based system considerably outperforms the conventional relay-based system.

Turbo Coded MIMO System with Adaptive Turbo Space- Time Processing for High-Speed Wireless Communications (고속 무선 통신을 위한 적응형 터보 시공간 처리를 갖는 터보 부호화된 다중 입출력 시스템)

  • 조동균;김상준;박주남;황금찬
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.9C
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    • pp.843-850
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    • 2003
  • Turbo coding and turbo processing have been known as methods close to Shannon limit in the aspect of wireless MIMO communications similarly to wireless single antenna communication. The iterative processing can maximize the mutual effect of coding and interference cancellation, but turbo coding has not been used for turbo processing because of the inherent decoding process delay. This paper proposes a turbo coded MIMO system with adaptive turbo parallel space-time (Turbo-PAST) processing for high-speed wireless communications and a enhanced cyclic redundancy check (E-CRC) scheme as an efficient and simple priori stopping criterion. Simulation results show that the Turbo-PAST outperforms conventional system with 1.3dB and the proposed E-CRC scheme effectively reduces the amount of turbo processing iterations from the point of average number of iterations.

Performance Analysis of MlMO-OFDMA System Combined with Adaptive Beamforming (다중 입출력과 적응형 빔형성 기술 결합기법을 적용한 직교주파수분할 다중 접속시스템의 성능 분석)

  • Chung, Jae-Ho;Choi, Seung-Won
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.2C
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    • pp.86-92
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    • 2011
  • This paper details the downlink performance analysis of an multiple antennas system that combines adaptive beamforming and spatial multiplexing (SM) Multiple Input Multiple Output (MIMO). The combination of MIMO signal processing with adaptive beamforming is applied to WiBro, the South Korean Orthogonal Frequency Division Multiple Access (OFDMA) system that follows the IEEE 802.16e standard. Performance analysis is based on the results of experiments and simulations obtained from a fixed-point simulation testbed. Simulations demonstrate that the MIMO Beamforming OFDMA system improves the required signal to noise ratio (SNR) over the conventional MIMO OFDMA system by 3 dB (QPSK) / 2.5 dB (16-QAM) for the frame error rate (FER) of 1% in the WiBro signal environments. From the implementation of the fixed-point simulation testbed and its experimental results, we verify the feasibility of the MIMO Beamforming technology for realizing a practical WiBro base station.

Performance Analysis of a Bit Mapper of the Dual-Polarized MIMO DVB-T2 System (이중 편파 MIMO를 쓰는 DVB-T2 시스템의 비트 매퍼 성능 분석)

  • Kang, In-Woong;Kim, Youngmin;Seo, Jae Hyun;Kim, Heung Mook;Kim, Hyoung-Nam
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.9
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    • pp.817-825
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    • 2013
  • The UHDTV system, which provides realistic service with ultra-high definite video and multi-channel audio, has been studied as a next generation broadcasting service. Since the conventional digital terrestrial transmission system is not capable to cover the increased transmission data rate of the UHDTV service, there are great necessity of researches about increase of data rate. Accordingly, the researches has been studied to increase the transmission data rate of the DVB-T2 system using dual-polarized MIMO technique and high order modulation. In order to optimize the MIMO DVB-T2 system where irregular LDPC codes are used, it is necessary to study the design of the bit mapper that matches the LDPC code and QAM symbols in MIMO channel. However, the research related to the design of the bit mapper has been limited to the SISO system. Therefore, this paper defines a new parameter that indicates the VND distribution of MIMO DVB-T2 system and performs the performance analysis according to the parameter which will be helpful for designing a MIMO bit mapper.

Compressive Sensing for MIMO Radar Systems with Uniform Linear Arrays (균일한 선형 배열의 다중 입출력 레이더 시스템을 위한 압축 센싱)

  • Lim, Jong-Tae;Yoo, Do-Sik
    • Journal of Advanced Navigation Technology
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    • v.14 no.1
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    • pp.80-86
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    • 2010
  • Compressive Sensing (CS) has been widely studied as a promising technique in many applications. The CS theory tells that a signal that is known to be sparse in a specific basis can be reconstructed using convex optimization from far fewer samples than traditional methods use. In this paper, we apply CS technique to Multiple-input multiple-output (MIMO) radar systems which employ uniform linear arrays (ULA). Especially, we investigate the problem of finding the direction-of-arrival (DOA) using CS technique and compare the performance with the conventional adaptive MIMO techniques. The results suggest the CS method can provide the similar performance with far fewer snapshots than the conventional adaptive techniques.

Opportunistic Channel State Information Feedback for Eigen based Scheduling in Multiuser MIMO Systems (다중 사용자 다중 입출력 시스템에서 고유값 기반 스케줄링을 위한 선택적 채널 정보 피드백 기법)

  • Kim, Sung-Tae;Hong, Dae-Sik
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.46 no.7
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    • pp.6-12
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    • 2009
  • In this paper, we propose the opportunistic channel state information feedback scheme for eigen based scheduling in multiuser MIMO systems. According to 3GPP SMC channel model, the system capacity of MU-MIMO systems is severly degraded, since the antennas are highly correlated in urban macro cell. Although the eigen based scheduling scheme mitigates the adverse effect of the antenna correlation, it achieves only small amount of the multiuser diversity gain. Since the opportunistic channel state information scheme can achieve sufficient multiuser diversity gain, the system capacity of MU-MIMO systems can be improved. The system capacity improvement is verified by the computer simulation results.

A study on the implementation of digital anti-fire monitoring system with multipoint communication protocol (다중포인트 통신 프로토콜을 지원하는 디지털 화재 방지 모니터링 시스템 구현에 관한 연구)

  • Kim, Ki-Jung
    • The Journal of the Korea institute of electronic communication sciences
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    • v.7 no.6
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    • pp.1423-1428
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    • 2012
  • In this paper, we investigated an implementation of anti-fire monitoring system based on the RS-485 communication to support local area coverage within a range of 1 Km range. We developed a Multi Point Communication Protocol supporting input/output information processing and control up to 8128 terminal check points, which provides an interface between the anti-fire monitoring system receiver and multiplex transponders. Additionally, a multiplex transponders controller has been designed for the implemented system to comply with the government regulation on fire protection, especially to monitor, report and control 1016 terminal check points within the time limit.

A Study on Buffer and Shared Memory Optimization for Multi-Processor System (다중 프로세서 시스템에서의 버퍼 및 공유 메모리 최적화 연구)

  • Kim, Jong-Su;Mun, Jong-Uk;Im, Gang-Bin;Jeong, Gi-Hyeon;Choe, Gyeong-Hui
    • The KIPS Transactions:PartA
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    • v.9A no.2
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    • pp.147-162
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    • 2002
  • Multi-processor system with fast I/O devices improves processing performance and reduces the bottleneck by I/O concentration. In the system, the Performance influenced by shared memory used for exchanging data between processors varies with configuration and utilization. This paper suggests a prediction model for buffer and shared memory optimization under interrupt recognition method using mailbox. Ethernet (IEEE 802.3) packets are used as the input of system and the amount of utilized memory is measured for different network bandwidth and burstiness. Some empirical studies show that the amount of buffer and shared memory varies with packet concentration rate as well as I/O bandwidth. And the studies also show the correlation between two memories.

Design of Multi-modal Browser for Post-PC (지능정보단말용 멀티모달 브라우저 설계)

  • 이동우;조수선;한동원
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.10e
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    • pp.586-588
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    • 2002
  • 정보통신 분야의 기술 발달이 가속화됨에 따라 종합 정보기기 개념의 PC와는 달리 정보이용 환경과 사용목적에 따라 용도가 단순하면서도 제공 기능별로 특화되고 사용자 편의성을 극대화시키는 새로운 컴퓨팅 기술과 정보기기의 요구가 증대되고 있다. 그러나 Post-PC의 특성상 기존 PC와는 달리 입출력의 제한 및 시스템 자원의 제약사항이 않은 게 사실이다. 본 논문에서는 이러한 환경에 맞는 웹 브라우저를 설계하고 개발하는 것이 목적이다. Post-PC의 입출력의 제약 사항을 극복하기 위한 방법으로 입출력의 다양성을 지원하는 다중인식 지원 선택형 브라우저를 설계한다

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