A Proposal of Simplified Viterbi Equalizer Applied to FWA Systems Employing 64QAM Signals

Hiroshi YOSHIOKA  Yushi SHIRATO  Kazuji WATANABE  

Publication
IEICE TRANSACTIONS on Communications   Vol.E89-B   No.3   pp.784-790
Publication Date: 2006/03/01
Online ISSN: 1745-1345
DOI: 10.1093/ietcom/e89-b.3.784
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Wireless Communication Technologies
Keyword: 
64QAM,  FWA,  Viterbi equalizer,  

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Summary: 
We propose a novel simplified Viterbi equalizer for high symbol rate FWA (Fixed Wireless Access) systems carrying 64QAM signals. Reduced complexity and improved performance are achieved adopting two approaches. The first one is reducing the number of survival paths, taking advantage of the large D/U common in LOS (line of sight) communications. The second one is using a multi-stage process to generate desired signal replicas based on their likelihoods. Computer simulations confirm that the proposed replica generation method offers a performance improvement of about 1 dB and the proposed Viterbi equalizer offers reduced complexity with no performance penalty compared to full Viterbi equalizer.