• DocumentCode
    1463441
  • Title

    Efficient LLR Calculation for Non-Binary Modulations over Fading Channels

  • Author

    Yazdani, Raman ; Ardakani, Masoud

  • Author_Institution
    Dept. of Electr. & Comput. Eng., Univ. of Alberta, Edmonton, AB, Canada
  • Volume
    59
  • Issue
    5
  • fYear
    2011
  • fDate
    5/1/2011 12:00:00 AM
  • Firstpage
    1236
  • Lastpage
    1241
  • Abstract
    Log-likelihood ratio (LLR) computation for non-binary modulations over fading channels is complicated. A measure of LLR accuracy on asymmetric binary channels is introduced to facilitate good LLR approximations for non-binary modulations. Considering piecewise linear LLR approximations, we prove convexity of optimizing the coefficients according to this measure. For the optimized approximate LLRs, we report negligible performance loss compared to true LLRs.
  • Keywords
    fading channels; modulation; optimisation; asymmetric binary channels; efficient LLR calculation; fading channels; log-likelihood ratio computation; nonbinary modulations; optimized approximate LLR; piecewise linear LLR approximations; Accuracy; Decoding; Fading; Linear approximation; Parity check codes; Piecewise linear approximation; Log-likelihood ratio (LLR); bit-interleaved coded modulation (BICM); fading channels; low-density parity-check (LDPC) codes; piecewise linear approximations;
  • fLanguage
    English
  • Journal_Title
    Communications, IEEE Transactions on
  • Publisher
    ieee
  • ISSN
    0090-6778
  • Type

    jour

  • DOI
    10.1109/TCOMM.2011.022811.090261
  • Filename
    5723044
    • Link To Document
    https://search.isc.ac/dl/search/defaultta.aspx?DTC=49&DC=1463441