• Title/Summary/Keyword: rate-adaptivity

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On the Construction of Polar Codes for Rate Adaptive Distributed Source Coding (부호율 적응적 분산 소스 부호화를 위한 극부호의 설계)

  • Kim, Jaeyoel;Kim, Jong-Hwan;Trang, Vu Thi Thuy;Kim, Sang-Hyo
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.10
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    • pp.3-10
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    • 2015
  • Application of polar codes to rate-adaptive asymmetric Slepian-Wolf coding is considered. We propose a method of constructing polar codes which supports rate adaptivity. The proposed polar distributed source coding with successive cancellation list decoding performs closer to the Slepian-Wolf bound than the low density parity check accumulate (LDPCA) codes in the same framework.

A Locally Adapative Fixed Rate DCT Image Coding (고정 부호화율의 국부적응 영상 변환부호화)

  • 심영석;고재홍;이상학
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.14 no.1
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    • pp.22-29
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    • 1989
  • An efficient fixed rate adaptive transform coding is described. Adaptivity is provided by assigning more bits to high ac energy blocks and less bits to low ac energy blocks. Practical and relatively simple adaptation scheme is developed. Overall complexity of our scheme is comparable to the Chen and Smith's scheme. The rate will be adjusted in the same manner as in fixed transform coding. Good performance of the proposed scheme is presented in terms of signal to noise ratio compared with the well known Chen&Smith's scheme. Subjective tests are also presented.

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LDPC Code Design and Performance Analysis for Distributed Video Coding System (분산 동영상 부호화 시스템을 위한 LDPC 부호 설계 및 성능 평가)

  • Noh, Hyeun-Woo;Lee, Chang-Woo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.1A
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    • pp.34-42
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    • 2012
  • Low density parity check (LDPC) code is widely used, since it shows superior performance close to Shannon limit and its decoding complexity is lower than turbo code. Recently, it is used as a channel code to decode Wyner-Ziv frames in distributed video coding (DVC) system. In this paper, we propose an efficient method to design the parity check matrix H of LDPC codes. In order to apply LDPC code to DVC system, the LDPC code should have rate compatibility. Thus, we also propose a method to merge check nodes of LDPC code to attain the rate compatibility. LDPC code is designed using ACE algorithm and check nodes are merged for a given code rate to maximize the error correction capability. The performance of the designed LDPC code is analyzed extensively by computer simulations.