Abstract
Abstract In this paper, a new approximated MAP algorithm for soft bit decision from QAM symbols is proposed for Gray Coded QAM signals, based on the Max-Log-MAP and a Gray coded QAM signal can be separated into independent two Gray coded PAM signal, M-PAM on I axis with M symbols and N-PAM on Q axis with N symbols. The Max-Log-MAP used distance comparisons between symbols to get the soft bit decision instead of mathematical exponential or logarithm functions. But in accordance with the increase of the number of symbols, the number of comparisons also increase with high complexity. The proposed algorithm is used with the Euclidean distance and constituted with plain arithmetic functions, thus we can know intuitively that the algorithm has low implementing complexity comparing to conventional ones. Key Words : Soft Decision, Log Likelihood, QAM, Gray Mapping, Max-Log-MAP * 교신저자 : 현광민(kamihyun@gwnu.ac.kr)접수일 09년 10월 04일 수정일 (1차 09년 11월 30일, 2차 09년 12월 11일) 게재확정일 09년 12월 16일
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of the Korea Academia-Industrial cooperation Society
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
