Design and Decoding LDPC Codes With Low Complexity

  • Author / Creator
    Zheng, Chao
  • This thesis presents low complexity design and decoding schemes for low density parity check (LDPC) codes. First, we consider the iterative decoding of LDPC codes on multiple-input-multiple-output bit-interleaved coded modulation (MIMO-BICM) channels and two-way relay channels. More specifically, we study the log-likelihood ratio (LLR) calculation under MIMO-BICM channels when perfect channel information is known and LLR calculation for two-way relay channels when no channel information is known at the receiver. We propose the optimum piece-wise linear approximation in the sense of maximizing the achievable rate of the channel. Second, we introduce a novel “universal” LDPC code design method. We design universal LDPC codes based on our method and show that, compared to existing methods, a lager percentage of capacity is obtained. Then, we propose two conjectures about the extreme distributions under min-sum decoding based on numerical observations.

  • Subjects / Keywords
  • Graduation date
    Spring 2012
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.