• Title/Summary/Keyword: common channel

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Ananlysis of decorrelating detector in the presence of the residual MAI (잔여 다원접속간섭을 고려한 역상관 검출기의 성능분석)

  • 김동인
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.8
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    • pp.2090-2098
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    • 1996
  • This paper analyzes decorrelating detector for synchronous packet CDMA communications where a set of quasiorthogonal code waveforms are generated from a common code by assigning distinct initial code phases to all users. In this analysis, we characterize the residual multiple-access interference (MAI) caused by possibletiming offsets when synchronous and simultanceous packet transmissions are on the reverse link of centralize networks. Also, to show feasibility of decorrelating detector employing the common code, we further investigate its robustness against the multipath channel. It is demonstrated that the decorrelating detector greatly reduces the residual MAI to the order of N$^{-2}$ , N number of chips/bit, and yields significant performance gain compared to the single user detector.

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A Study on the High Integrated 1TC SONOS flash Memory (고집적화된 1TC SONOS 플래시 메모리에 관한 연구)

  • 김주연;김병철;서광열
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.5
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    • pp.372-377
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    • 2003
  • To realize a high integrated flash memory utilizing SONOS memory devices, the NOR type ITC(one Transistor Cell) SONOS flash arrays are fabricated and characterized. This SONOS flash arrays with the common source lines are designed and fabricated by conventional 0.35$\mu\textrm{m}$ CMOS process. The thickness of ONO for memory cells is tunnel oxide of 34${\AA}$, nitride of 73${\AA}$ and blocking oxide of 34${\AA}$ . To investigate operating characteristics, CHEI(Channel Hot Electron Injection) method and bit line method are selected as the program and 4he erase operation, respectively. The disturbance characteristics ,according to the program/erase/read cycling are also examined. The degradation characteristics are investigated and then the reliability of SONOS flash memory is guaranteed.

An Abnormal Breakpoint Data Positioning Method of Wireless Sensor Network Based on Signal Reconstruction

  • Zhijie Liu
    • Journal of Information Processing Systems
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    • v.19 no.3
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    • pp.377-384
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    • 2023
  • The existence of abnormal breakpoint data leads to poor channel balance in wireless sensor networks (WSN). To enhance the communication quality of WSNs, a method for positioning abnormal breakpoint data in WSNs on the basis of signal reconstruction is studied. The WSN signal is collected using compressed sensing theory; the common part of the associated data set is mined by exchanging common information among the cluster head nodes, and the independent parts are updated within each cluster head node. To solve the non-convergence problem in the distributed computing, the approximate term is introduced into the optimization objective function to make the sub-optimization problem strictly convex. And the decompressed sensing signal reconstruction problem is addressed by the alternating direction multiplier method to realize the distributed signal reconstruction of WSNs. Based on the reconstructed WSN signal, the abnormal breakpoint data is located according to the characteristic information of the cross-power spectrum. The proposed method can accurately acquire and reconstruct the signal, reduce the bit error rate during signal transmission, and enhance the communication quality of the experimental object.

Delay Performance Analysis of Signalling Network Functions in Common Channel Signalling System (공통선 신호 시스템에서 신호망 기능부의 지연 성능 분석)

  • 박철근;정태욱;이유태
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.7B
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    • pp.1226-1235
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    • 2000
  • 신호망에서의 지연은 망관리 행위의 응답시간에 직접적인 영향을 미치기 때문에 모든 제어정보는 가장 효과적으로 전송되어야 한다. 신호망이 효율적으로 운용되는지 뿐만 아니라 신호망의효과적인 설계를 위해서 신호시스템의 성능을 아는 것이 매우 중요하다. 본 논문에서는 공통선 신호 시스템의 신호망 기능부의 지연 성능을 분석하였다. 분석은 ITU-T 규격을 기반으로 다른 계층의 프로토콜에 독립적인 큐잉모델을 만들어 대기체계분석을 통하여 이루어졌다. 또한 신호망 기능부가 신호 메시지 처리부와 신호망 관리부로 나누어져 구성되는 것도 고려하여 모델링하였다.

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Development of L1 C/A Code GPS receiver using chipset (Chip Set을 이용한 L1 C/A Code GPS 수신기 개발)

  • 심우성;박상현;이상정
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1376-1379
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    • 1996
  • In this paper a GPS receiver is developed using commercial chipsets. GP2010 RF front end and GP2021 Multi-channel correlator of GEC PLESSY are adapted in designing the receiver hardware. MC 68340 is used for controlling the correlator GP2021 and implementing the navigation processing. Also presented are some test results of the developed receiver whose software has an interrupt driven structure rather than common real-time kernel based structure.

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Field Testing of High-Speed Power Line Communications (고속 전력선통신의 현장성능 분석)

  • Kim, Sang-Jo;Lee, Byung-Gu;Kim, Geun-Young;Kim, Sok-Ho
    • 한국정보통신설비학회:학술대회논문집
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    • 2009.08a
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    • pp.227-230
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    • 2009
  • In this paper, the results of field testing of high-speed power line in-home networking in Korea are reported. When multiple networks share a common channel, they can interfere destructively and reduce system capacity. This is major problem in-home power line communications, especially in MDU deployments. The effects of neighboring network interference in power line communications are reported.

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CCITT NO. 7 신호방식 소개

  • 송평중;이남희
    • Proceedings of the Korean Institute of Communication Sciences Conference
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    • 1986.04a
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    • pp.18-23
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    • 1986
  • The CCITT No.7 is a general purpose common channel signalling system developed by CCITT. The paper, which is weitten according to CCITT Red book Fascicle VI.7 and VI.8, gives an overall of the introduction to CCITT No.7: 'background of No.7 being recommended'. 'application fields of No.7', 'overall structure of No.7'. and 'functions of each layer'. The trends of future CCITT study is also included.

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Conversion of Common Speech Database into Telephone Channel Environment (공용 음성 데이터 베이스 PBW452의 전화망 변환)

  • Park Junho;Kim Taeyoon;Ko Hanseok
    • Proceedings of the Acoustical Society of Korea Conference
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    • autumn
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    • pp.37-40
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    • 2000
  • 전화망 음성 인식 시스템에서 사용할 수 있는 데이터베이스 구축의 질과 양은 인식 시스템의 성능에 중대한 영향을 미친다. 따라서, 전화망 음성 데이터 베이스 구축에 관한 효과적인 방법들이 연구되고 있다. 본 논문은 공용으로 사용할 수 있는 음성 데이터 베이스의 전화망 변환 방법 및 활용 방안에 대하여 소개한다.

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Effect of Lespedezea Cuneata on the Contraction of Rabbit Common Carotid Artery and Corpus Cavernosum (야관문(夜關門)이 토끼의 혈관과 음경해면체 수축에 미치는 영향)

  • Park, Sun Young;Kim, Ho Hyun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.27 no.6
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    • pp.809-817
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    • 2013
  • The aim of this study was to evaluate the mechanism of vasodilation of Lespedezea cuneata(LC) in rabbit common carotid artery and cavernosal smooth muscle. LC relaxed arterial strips precontracted with norepinephrine and cavernosal strips precontracted with phenylephrine. The arterial relaxation effects of LC was endothelium-dependent. $N{\omega}$-nitro-L-arginine(L-NNA), NOS inhibitor, methylene blue(MB), cGMP inhibitor, indomethacin(IM), cyclo-oxygenase inhibitor and tetraethylammonium chloride(TEA), KCa-channel blocker attenuate the relaxation responses of LC in arterial strips. In $Ca^{2+}$-free krebs-ringer solution, pretreatment of LC extract significantly reduced the contraction induced by addition $Ca^{2+}$. L-NNA reduced LC extract-induced relaxation in cavernosal strips, but IM, TEA and MB didn't affect LC extract-induced relaxation. When LC extract was applicated on human umbilical vein endothelial cell, the nitric oxide concentration was increased. We conclude that in rabbit common carotid artery, LC may suppress influx of extra-cellular $Ca^{2+}$ through the release of endothelium derived relaxing factor including nitric oxide, prostacyclin, endothelium derived hyperpolarizing factor. And LC exerts a relaxing effect on corpus cavernosum through activating the NO.