• Title/Summary/Keyword: bit error rate

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Study of the Switching Errors in an RSFQ Switch by Using a Computerized Test Setup (자동측정장치를 사용한 RSFQ switch의 Switching error에 관한 연구)

  • Kim, Se-Hoon;Baek, Seung-Hun;Yang, Jung-Kuk;Kim, Jun-Ho;Kang, Joon-Hee
    • Progress in Superconductivity
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    • v.7 no.1
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    • pp.36-40
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    • 2005
  • The problem of fluctuation-induced digital errors in a rapid single flux quantum (RSFQ) circuit has been a very important issue. In this work, we calculated the bit error rate of an RSFQ switch used in superconductive arithmetic logic unit (ALU). RSFQ switch should have a very low error rate in the optimal bias. Theoretical estimates of the RSFQ error rate are on the order of $10^{-50}$ per bit operation. In this experiment, we prepared two identical circuits placed in parallel. Each circuit was composed of 10 Josephson transmission lines (JTLs) connected in series with an RSFQ switch placed in the middle of the 10 JTLs. We used a splitter to feed the same input signal to both circuits. The outputs of the two circuits were compared with an RSFQ exclusive OR (XOR) to measure the bit error rate of the RSFQ switch. By using a computerized bit-error-rate test setup, we measured the bit error rate of $2.18{\times}10^{-12}$ when the bias to the RSFQ switch was 0.398 mA that was quite off from the optimum bias of 0.6 mA.

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Simulation of Average Bit Error Rate for Computer Hard Disk Drive System Using Planar Silicon Head (평면 실리콘 헤드를 사용한 하드 디스크 드라이브 시스템의 Average Bit Error Rate 시뮬레이션)

  • 서정욱;조순철;김용수;노광춘
    • Journal of the Korean Magnetics Society
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    • v.8 no.6
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    • pp.395-399
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    • 1998
  • 평면 실리콘 헤드를 사용한 디스크 드라이브(hard disk:HDD) 시스템의 average bit error rate(ABER)를 계산하였다. ABER을 구하기 위해 3차원 유한 요소법을 사용하여 헤드 자장 분포를 구하고 error rate response surface(ERRS)를 구하엿다. 다음에 track misregistration(TMR)과 계산되어진 ERRS를 컨볼루션하여 ABER을 시뮬레이션 하였다. 허용할 수 잇는 에러 율이 10-6이라 하고 트랙 피치가 3.7$\mu$m일 때, 요구되는 TMR은 0.36$\mu$m이었다. 이는 트랙 피치의 9.7이었다.

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Bit Error Rate measurement of an RSFQ switch by using an automatic error counter (자동 Error counter를 이용한 RSFQ switch 소자의 Bit Error Rate 측정)

  • Kim Se Hoon;Kim Jin Young;Baek Seung Hun;Jung Ku Rak;Hahn Taek Sang;Kang Joon Hee
    • Progress in Superconductivity and Cryogenics
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    • v.7 no.1
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    • pp.21-24
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    • 2005
  • The problem of fluctuation-induced digital errors in a rapid single flux quantum (RSFQ) circuit has been very important issue. So in this experiment, we calculated error rate of RSFQ switch in superconductiyity ALU, The RSFQ switch should have a very low error rate in the optimal bias. We prepared two circuits Placed in parallel. One was a 10 Josephson transmission lines (JTLs) connected in series, and the other was the same circuit but with an RSFQ switch placed in the middle of the 10 JTLs. We used a splitter to feed the same input signal to the both circuits. The outputs of the two circuits were compared with an RSFQ XOR to measure the error rate of the RSFQ switch. By using a computerized bit error rate test setup, we measured the bit error rate of 2.18$\times$$10^{12}$ when the bias to the RSFQ switch was 0.398mh that was quite off from the optimum bias of 0.6mA.

Plug & Play quantum cryptography system (Plug & Play 양자암호 시스템)

  • Lee, Kyung-Woon;Park, Chul-Woo;Park, Jun-Bum;Lee, Seung-Hun;Shin, Hyun-Jun;Park, Jung-Ho;Moon, Sung-Wook
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.44 no.3
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    • pp.45-50
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    • 2007
  • We present a auto compensating quantum key distribution system based on optical fiber at 1550nm. In the quantum key transmission system, main control board and phase modulation driving board are fabricated for auto controlling quantum key distribution(QKD). We tested the single photon counts per dark counts for a single photon detector, quantum key distribution rate($R_{sift}$) and the quantum bit error rate (QBER). Quantum bit error rate of 3.5% in 25km QKD is obtained. This system is commercially available.

An Exact Closed-Form Expression for Bit Error Rate of Decode-and-Forward Relaying Using Selection Combining over Rayleigh Fading Channels

  • Bao, Vo Nguyen Quoe;Kong, Hyung-Yun
    • Journal of Communications and Networks
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    • v.11 no.5
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    • pp.480-488
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    • 2009
  • Cooperative transmission is an effective solution to improve the performance of wireless communications over fading channels without the need for physical co-located antenna arrays. In this paper, selection combining is used at the destination instead of maximal ratio combing to optimize the structure of destination and to reduce power consumption in selective decode-and-forward relaying networks. For an arbitrary number of relays, an exact and closed-form expression of the bit error rate (BER) is derived for M-PAM, M-QAM, and M-PSK, respectively, in both independent identically distributed and independent but not identically distributed Rayleigh fading channels. A variety of simulations are performed and show that they match exactly with analytic ones. In addition, our results show that the optimum number of relays depend not only on channel conditions (operating SNRs) but also on modulation schemes which to be used.

Error Adaptive Transport Protocol in Variable Error Rate Environment for Wireless Sensor Networks

  • Dang, Quang-Bui;Hwang, Won-Joo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.4B
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    • pp.208-216
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    • 2007
  • Wireless Sensor Networks (WSNs) are characterized by low capacity on each nodes and links. Wireless links have high bit error rate (BER) parameter that changes frequently due to the changes on network topology, interference, etc. To guarantee reliability in an error-prone environment, a retransmission mechanism can be used. In this mechanism, the number of retransmissions is used as a parameter that controls reliability requirement level. In this paper, we propose an Error Adaptive Transport Protocol (EATP) for WSNs that updates the number of retransmissions regularly to guarantee reliability during bit error rate changes as well as to utilize energy effectively. The said algorithm uses local information, thus, it does not create overhead problem.

An Efficient ARQ for Multi-Hop Underwater Acoustic Channel with Long Propagation Delay and High Bit-Error Rate

  • Lee, Jae-Won;Jang, Youn-Seon;Cho, Ho-Shin
    • The Journal of the Acoustical Society of Korea
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    • v.30 no.2
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    • pp.86-91
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    • 2011
  • In the underwater communications, the acoustic channel is in poor communication conditions, such as long propagation delay, narrow bandwidth, and high bit-error rate. For these bad acoustic channels, we propose an efficient automatic repeat request (ARQ) for multi-hop underwater network by using the concepts of concurrent bi-directional transmission, multiple sub-packets, and overhearing data packet instead of the acknowledgement signal. Our results show that the proposed ARQ significantly reduces the transmission latency especially in high BER compared with the existing Stop and Wait ARQ.

Approximate Expression of Bit Error Rate in Uplink MC-CDMA Systems with Equal Gain Combining

  • Develi, Ibrahim;Akdagli, Ali
    • Journal of Communications and Networks
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    • v.15 no.1
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    • pp.25-30
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    • 2013
  • Uplink multicarrier code-division multiple-access (MC-CDMA) with equal gain combining (EGC) over Nakagami fading channels is considered. An improved expression which is a feasible alternative for the bit error rate (BER) performance evaluation of MC-CDMA signals is proposed. Simulated annealing algorithm is employed to obtain the optimum value of the coefficients belonging to the proposed expression. Numerical examples show that the performance curves computed by the improved expression are in good agreement with the results obtained by the exact expression. Thus, the proposed expression can improve the accuracy of BER performance evaluation that has been realized by the approximate expression.