New recursive, systematic rate-(N-1)/N convolutional encoders for N between 2 and 20 and memory M between 1 and 6 are presented. These encoders generate codes having optimal distance spectra, and were obtained by performing an efficient search. The search possibilities were limited by exploiting the structure of the encoder using various combinatorial arguments. Many of the codes improve upon previously reported results and are attractive for use in high data-rate applications in conjunction with iterative decoding schemes.
By: M. Tüchler and A. Dholakia
Published in: RZ3409 in 2002
LIMITED DISTRIBUTION NOTICE:
This Research Report is available. This report has been submitted for publication outside of IBM and will probably be copyrighted if accepted for publication. It has been issued as a Research Report for early dissemination of its contents. In view of the transfer of copyright to the outside publisher, its distribution outside of IBM prior to publication should be limited to peer communications and specific requests. After outside publication, requests should be filled only by reprints or legally obtained copies of the article (e.g., payment of royalties). I have read and understand this notice and am a member of the scientific community outside or inside of IBM seeking a single copy only.
Questions about this service can be mailed to reports@us.ibm.com .