• Title/Summary/Keyword: bit error rate

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Research on Fault Tolerant Avionics Memory Design through Multi Level Cell Flash Memory Reliability Analysis (멀티 레벨 셀 플래시 메모리 신뢰성 분석을 통한 항공 전자장비용 내결함성 메모리 설계 연구)

  • Jeong, Sang-gyu;Jun, Byung-kyu;Kim, Young-mok;Chang, In-ki
    • Journal of Advanced Navigation Technology
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    • v.20 no.4
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    • pp.321-328
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    • 2016
  • Typical MLC NAND flash devices are considered less reliable than SLC NAND flash devices. Although raw bit error rate (RBER) of MLC flash had been considered approximately 1000times or more higher than that of SLC flash, recent research conducted on Google's data center shows that it is much lower than such expectation. Based on the research, we devised In Drive Data Duplication (IDDD) scheme that efficiently exploit MLC flash's sufficient capacity to improve its data reliability without structural complexity increment using SSD intrinsic firmware layer, and showed the data reliability expectation of MLC flash could be significantly higher than that of SLC flash from measured and calculated error rates. Even though RBER of SLC flash was lower than that of MLC flash in 44 out of 48 cases we studied, applying IDDD scheme, RBER of MLC flash was became lower than that of SLC in all 48 cases and uncorrectable bit error rate (UBER) of MLC flash was became lower than that of SLC flash in 45 out of 48 cases.

A Study on Hamming Codes for Mitigating ISI on the Diffusion-based Molecular Communication Channel (확산기반 분자통신 채널에서 ISI 완화를 위한 해밍 부호에 관한 연구)

  • Cheong, Ho-Young
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.14 no.1
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    • pp.1-6
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    • 2021
  • In this paper, in order to mitigate ISI(inter-symbol interference) in a diffusion-based molecular communication channel, an ISI Hamming code is proposed in which ISI characteristics are applied to a channel decoding algorithm. In order to prove the bit error rate performance of the proposed channel code, the bit error rate performance of the major channel codes applied to the molecular communication channel with ISI was compared and analyzed through simulation. From the simulation results, it can be seen that the bit error rate performance of the ISI Hamming code is the best when the number of radiated molecules is less than or equal to 1100. In addition, when the number of transmitted molecules is M=1000, the decoding method of the ISI Hamming code proposed in this paper has improved the bit error rate of approximately 5.9×10-5 compared to the Hamming code using only soft values. Compared with the ISI-mitigating channel code, which is effective for removing ISI in the molecular communication channel, the ISI Hamming code proposed in this paper is the most advantageous in a channel environment where the number of transmitted molecules is not big (M<1100). And we can see that the ISI-mitigating channel code is more advantageous when the number of transmitted molecules is large(M>1100).

Performance Analysis of the Multi-User Detector Employing a Hybrid Interference Cancellation Scheme in a WCDMA System (WCDMA 시스템에서 Hybrid Interference Cancellation 기법을 적용한 다중사용자 검파기의 성능분석)

  • 서정욱;오창헌;장은영;조성준
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.6 no.2
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    • pp.221-227
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    • 2002
  • In this paper, in order to know the effect of the interference, we have analyzed the BER (Bit Error Rate) performance of the MUD(Multi-User Detector) employing HIC(Hybrid Interference Cancellation) scheme for the asynchronous WCDMA system based on 3GPP(3rd Generation Partnership Project) Spec. through the In this paper, in order to know the effect of the interference, we have analyzed the BER (Bit Error Rate) performance of the MUD(Multi-User Detector) employing HIC(Hybrid Interference Cancellation) scheme for the asynchronous WCDMA system based on 3GPP(3rd Generation Partnership Project) Spec. through the computer simulation. we have assumed Rayleigh fading channel. And we have compared its BER performance with SIC's(Successive Interference Cancellation) and with PIC's(Parallel Interference Cancellation), which are the representative schemes in the subtractive interference cancellation. From the results, it is shown that PlC or HIC is effective for high data-rate users and SIC of HIC for low data-rate users to eliminate the interference. Regardless of the data rate, it is reasonable to use the HIC structure for WCDMA system to satisfy all of users' services. The reason is that the SIC scheme in front of HIC can guarantee the performance of low power users to cancel the serious interference caused by the high power users, while PIC in the rear of it can guarantee the performance of high power users to cancel the interference caused by the low power users.

Audio Watermark Design Using Hilbert Transform

  • Lee, Jin-Geol
    • The Journal of the Acoustical Society of Korea
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    • v.25 no.2E
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    • pp.56-59
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    • 2006
  • A novel audio watermark design using Hilbert transform is proposed, and its superiority of performance over the existing design using the absolute values of the audio signal is demonstrated experimentally with measurements of bit error rate (BER) in correlation based decoder. (Classification No. 3.3)

BER Performance Analysis of Hierarchical-MPSK Using Phase Parameters (위상 파라미터 도출을 통한 H-MPSK의 BER 성능 분석)

  • Lee, Won-Joon;Park, Sang-Kyu
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.4
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    • pp.375-380
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    • 2009
  • Bit error rate(BER) performance of each bit for hierarchical M-ary phase shift keying(H-MPSK) modulation scheme is changed according to the phase parameters. Thus, a method to find the phase parameters appropriate to the requests of the system is needed. In this paper, we propose a method to obtain the phase parameters from an approximate approach of BER for H-MPSK and verify a validity of the proposed method through the previously provided expression for analyzing an exact error probability of H-MPSK.

Performance Analysis of Hybrid Decode-and-Forward Schemes for 2-hop Wireless Network (2-홉 무선 네트워크를 위한 하이브리드 복호 후 전달 기법의 성능 분석)

  • Kong, Hyung-Yun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.12A
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    • pp.949-961
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    • 2009
  • This paper analyses BER (Bit Error Rate) performance of 2-hop wireless communications networks with hybrid decode-and-forward (HDF) relays. The conventional HDF method is usually based on the receive signal-to-noise ratio (SNR) for the relay to decide whether to forward the decoded data in order to obviate the erroneous detection at the relay. In contrast, we propose a new solution of using log-likelihood ratio (LLR) as an efficient alternative to SNR. The approximate BER expressions of different HDF schemes are also derived and verified by Monte-Carlo simulations. In addition, we compute the optimum thresholds for HDF schemes. A variety of numerical results demonstrate that the new LLR-based HDF significantly outperforms the SNR-based HDF for any threshold level and relay location under flat Rayleigh fading channel plus AWGN (Additive White Gaussian Noise).

Performance Evaluation of MC-DS-CDMA Systems over Time Variant Channels (시변 채널 하에서의 MC-DS-CDMA 시스템의 성능 분석)

  • Choi, Seung-Kuk
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.3
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    • pp.581-586
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    • 2010
  • MC-DS-CDMA is technique where a single data symbol is transmitted at multiple subcarriers which are orthogonal to each other. With this technique, frequency diversity can be achieved. Time variant channels lead to interchannel interference which increases the bit error rate for MC-DS-CDMA systems. The performance of PSAM MC-DS-CDMA system over time variant channels is analyzed. The BER performance of this system over multipath fading environment is evaluated, considering the channel estimation error, carrier frequency offset.

Comparison of Channel Estimation Schemes for Digital Broadcasting System in a Mobile Environment (이동 환경에서 디지털 방송 시스템을 위한 채널 추정 기법의 성능 비교)

  • Kim, Ki-Nam;Kim, Jin-Ho;Cho, Sung-Joon
    • Journal of Advanced Navigation Technology
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    • v.9 no.1
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    • pp.41-47
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    • 2005
  • In this paper, the performances of various channel estimation schemes for DVB-H system are investigated. The linear interpolation, the second order interpolation, the cubic spline interpolation, and the time-domain interpolation, which are used in frequency domain, are chosen as the channel estimation schemes. We derived the performances of Mean Square Error (MSE), Bit Error Rate (BER), and the complexity of calculation in Rayleigh and Rician fading channel through computer simulations. From the simulation results, the cubic spline interpolation shows the best performance under high $E_b/N_0$ environments.

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Performance Analysis of Coded FSK System for Multi-hop Wireless Sensor Networks (멀티 홉 무선 센서 네트워크를 위한 부호화된 FSK 시스템의 성능 해석)

  • Oh, Kyu-Tae;Roh, Jae-Sung
    • Journal of Advanced Navigation Technology
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    • v.11 no.4
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    • pp.408-414
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    • 2007
  • Research advances in the areas of micro-sensor device and wireless network technology, has made it possible to develop energy efficient and low cost wireless sensor nodes. In this paper, the forward error control (FEC) scheme for lower power consumption and excellent BER(Bit Error Rate) performance during transmission propose in multi-hop wireless sensor network based on FSK modem. The FEC technique uses extra processing power related to encoding and decoding, it is need complex functions to be built into the sensor node. The probability of receiving a correct bit and codeword for relaying a frame over h nodes to the sink node is calculated as a function of channel parameter, number of hops, number of bits transmitted and the distance between the different nodes.

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