• Title/Summary/Keyword: LDGM codes

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Lossy Source Compression of Non-Uniform Binary Source via Reinforced Belief Propagation over GQ-LDGM Codes

  • Zheng, Jianping;Bai, Baoming;Li, Ying
    • ETRI Journal
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    • v.32 no.6
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    • pp.972-975
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    • 2010
  • In this letter, we consider the lossy coding of a non-uniform binary source based on GF(q)-quantized low-density generator matrix (LDGM) codes with check degree $d_c$=2. By quantizing the GF(q) LDGM codeword, a non-uniform binary codeword can be obtained, which is suitable for direct quantization of the non-uniform binary source. Encoding is performed by reinforced belief propagation, a variant of belief propagation. Simulation results show that the performance of our method is quite close to the theoretic rate-distortion bounds. For example, when the GF(16)-LDGM code with a rate of 0.4 and block-length of 1,500 is used to compress the non-uniform binary source with probability of 1 being 0.23, the distortion is 0.091, which is very close to the optimal theoretical value of 0.074.