• Title, Summary, Keyword: 에러 정정 부호

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FPGA Implementation of Reed-Solomon Encoder for image transmission (영상 전송을 위한 Reed-Solomon Encoder의 FPGA 구현)

  • Kim, Dong-Nyeon;Cai, Yu Qing;Byon, Kun-sik
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • pp.907-910
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    • 2009
  • This paper is the FPGA Implementation of Reed-Solomon Encoder that is one of Error control Codes. Reed-Solomon codes are block-based error control codes with a wide range of applications in digital communications. RS codes are strong on burst errors because it process signals as symbol. We simulate this system using Matlab from Mathworks and design it using System Generator from Xilinx. We refer Matlab source in Implementation of Reed-Solomon Error Control Coding for Compressed Images by Simon Anthony Raspa.

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2/3 Modulation Code and Its Vterbi Decoder for 4-level Holographic Data Storage (4-레벨 홀로그래픽 저장장치를 위한 2/3 변조부호와 비터비 검출기)

  • Kim, Gukhui;Lee, Jaejin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.10
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    • pp.827-832
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    • 2013
  • Holographic data storage system is affected by two dimensional intersymbol interference and inter-page interference. Especially, for multi-level holographic data storage system, since one pixel contains more than 1 bit, the system is more vulnerable to the error. In this paper, we propose a 2/3 modulation code for 4-level holographic data storage system. The proposed modulation code with error correcting capability could be compensated these interferences. Also, in this paper, we proposed a Viterbi decoder for 2/3 modulation code. The proposed Viterbi decoder eliminates unnecessary calculation. As a result, proposed 2/3 modulation code and Viterbi decoder has shown better performance than conventional one.

A Study on the performance evaluation with TCM and MTCM in the mobile radio environment (이동 무선 환경에서의 TCM 및 MTCM의 성능 비교 평가)

  • 김민호
    • Journal of the Korea Society of Computer and Information
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    • v.5 no.4
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    • pp.90-95
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    • 2000
  • In order to enhance the confidence in the mobile communication and improve the performance of the bit error, we have been using coding method. In the case of this, we have to add redundancy bits by using error correcting codes such as the block or convolutional codes. However, the result of redundancy bits causes to improve confidence. but to drop the efficiency in the bandwidth. We have studied coding method that we are able to get the good coding gain without any changes in the data transmission rates in the limited bandwidth. In this Paper, we design TCM(Trellis Coded Modulation) which was proposed by Ungerboeck and MTCM(Multiple TCM), with multiplicity(k=2), which was proposed by Divsalar, using the optimum encoder. As state number is varied in the optimum encoder, we compare the performance of the TCM and MTCM by using Monte Carlo simulation.

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Iterative Coding for High Speed Power Line Communication Systems (고속 전력선 통신 시스템을 위한 반복 부호화 기법)

  • Kim, Yo-Cheol;Cho, Bong-Youl;Lee, Jae-Jo;Kim, Jin-Young
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.11 no.5
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    • pp.185-192
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    • 2011
  • In this paper, we simulate and analyze performance of iterative coding scheme, double binary turbo code, for high speed power line communication (PLC) systems. PLC system has hostile environment for high speed data transmission, so error correction method is necessary to compensate effects of PLC channel. We employ the PLC model proposed by M. Zimmerman and Middleton Class A interference model, and system performance is evaluated in terms of bit error rate (BER). From the simulation results, we confirm double binary turbo code provides considerable coding gains to PLC system and BER performance is significantly improved as the number of iteration increase. It is also confirmed that BER performance increases as code rate is lager, while it decreases as the code rate is smaller.

Throughput Analysis of DS/CDMA System Applying Packet Combining Scheme over Nakagami Fading Channel (나카가미 페이딩 채널에서 패킷결합기법을 적용한 DS/CDMA 시스템의 전송율 분석)

  • 황재문;박진수
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.1
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    • pp.9-18
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    • 2003
  • In this paper, we analyzed the throughput of DS/CDMA system applying packet combining scheme combined with Type- I Hybrid ARQ scheme over AWGN channel and Nakagami fading channel with RAKE receiver. As the parameter for analysis, we used number of combined packet(L), number of diversity branch$({L_c})$, fading index(m), and length of packet(N), and used CRC-12 error detection code and (2,1,3) convolutional code. As a results, we found that throughput of system over Nakagami fading channel with RAKE receiver was superior to throughput over AWGN channel, and throughput of system decreases rapidly as channel degrades when number of combined packet(L) was increased. However throughput of system with the combining scheme was achieved even at low ${E_b}/{N_o}$. Also, we found that throughput of system was increased when fading index(m) and number of diversity branch$({L_c})$ were increased, but it was decreased when number of user(K) and length of packet(N) were increased.

The FEC decoder design of the spread spectrum basis which utilizes the VHDL (VHDL을 이용한 대역확산 시스템 기반의 FEC 디코더 설계)

  • 이재성;정운용;강병권;김선형
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • pp.300-303
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    • 2003
  • In this paper, a baseband module of the spread spectrum system with FPGA is designed. A spread spectrum system spreads the signal bandwidth necessary for information transmission. We focused on the design of FEC decoder, especially the convolutional code fo constraint length K=3, rate R=l/2, is designed. For the VHDL design the Xilinx Foundation 3.1 is used. As results, a spread spectrum modem with convolutional coding is designed and we have plan to apply this modem to short distances wireless communication.

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Error Correction Coding on the Transform Coded Image Transmission over Noisy Channel (잡음 채널에서 변환 부호화 영상 전송에 대한 에러 정정 부호)

  • 채종길;주언경
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.31B no.4
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    • pp.97-105
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    • 1994
  • Transform image coding using DCT is proved to be efficient in the absence of channel error but its performance degrades rapidly over noisy channel. In this paper, in the case of appling bit selcetive error correction coding that protects some significant bits in a codeword, an efficient allocation method of imformation bits and additive redundancy bits used for quantization and error correction coding respectively under constant transmission bit rate is proposed, and its performance is analyzed. As a result, without increasing trasmission bit rate, PSNR can be improved up to 7~8 [dB] below bit error rate $10^2$ and the image without blocking effect caused by bit error resulted from channel noise can be recostructed.

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Bit-selective Forward Error Correction for 14Kbps SBC-APCM (AQB) over Digital Mobile Communication Channels (디지털 이동통신 채널상의 14Kbps SBC-APCM(AQB)를 위한 비트선택적 에러정정부호)

  • 김민구;이재홍
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.6
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    • pp.821-828
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    • 1990
  • A forward error correction (FEC) technique is presented for speech data in 16 Kbps digital mobile communications. 14Kbps SBC-APCM(AQB) and QPSK are used as speech coding and modulation techniques, respectively. Because each bit in a speech data block had different importance, applying FEC to speech data bit-selectively in more effective than applying FEC to all speech data equally. To select bits in a speech data block to be protected by FEC the bit error sensitivity of each bit is computed. For a few BCH and Reed-Solomon codes used as bit-selective FEC the performance of the coding technique is computed.

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Reed Solomon CODEC Design For Digital Audio/Video, Communication Electronic Devices (디지털 오디오/비디오, 통신용 전자기기를 위한 Reed Solomon 복부호기 설계에 대해)

  • An Hyeong-Keon
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.42 no.11
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    • pp.13-20
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    • 2005
  • For Modern Consumer and Communication Elecronic Devices, Always Error Protecting HW and SW is used. The Core is RS(Reed Solomon) Codec in Galois Field GF($2^8$). Here New 2 to 3 Symbol RS Decoder Design and Encoder design Method using Normalized error position Value is described. Examples are given to show the methods are working well.

A performance analysis of layered LDPC decoder for mobile WiMAX system (모바일 WiMAX용 layered LDPC 복호기의 성능분석)

  • Kim, Eun-Suk;Kim, Hae-Ju;Shin, Kyung-Wook
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.4
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    • pp.921-929
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    • 2011
  • This paper describes an analysis of the decoding performance and decoding convergence speed of layered LDPC(low-density parity-check) decoder for mobile WiMAX system, and the optimal design conditions for hardware implementation are searched. A fixed-point model of LDPC decoder, which is based on the min-sum algorithm and layered decoding scheme, is implemented and simulated using Matlab model. Through fixed-point simulations for the block lengths of 576, 1440, 2304 bits and the code rates of 1/2, 2/3A, 2/3B, 3/4A, 3/4B, 5/6 specified in the IEEE 802.16e standard, the effect of internal bit-width, block length and code rate on the decoding performance are analyzed. Simulation results show that fixed-point bit-width larger than 8 bits with integer part of 5 bits should be used for acceptable decoding performance.