Global Design Methods for Raptor Codes Using Binary and Higher-Order Modulations
Abstract
We develop accurate and robust one-dimensional EXIT chart methods to design Raptor codes with binary and higher-order modulations on AWGN channels. We formulate the check-node degree distribution optimization as a linear program that directly accounts for the pre-code error correction capability and simultaneously optimizes over any desired range of rate operating points. The throughput curves predicted by the analysis are easily compared across different pre-code rates and pre-code error-correcting capabilities. For higher-order modulations we employ BICM on a standard Gray-mapped 16-QAM constellation. We further enhance the optimization by applying separate check-node degree distributions to the mapped MSBs and LSBs, which results in significant gains compared to a single check-node degree distribution.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2008
- Accession Number
- AD1108319
Entities
People
- Caleb K. Lo
- Jerome M. Shapiro
- Richard J. Barron
Organizations
- MITRE Corporation