Title :
Global design methods for raptor codes using binary and higher-order modulations
Author :
Barron, Richard J. ; Lo, Caleb K. ; Shapiro, Jerome M.
Author_Institution :
MITRE Corp., MA, USA
Abstract :
We develop accurate and robust one-dimensional EXIT chart methods to design raptor codes with binary and higher-order modulations on AWGN channels over any desired range of SNRs. We formulate the check-node degree distribution optimization as a linear program that optimizes a suitable objective function of the desired 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 standard Gray-mapped constellations. We further enhance the optimization by applying separate check-node degree distributions to the mapped MSBs and LSBs. Simulated throughput curves using the designed codes for QPSK and 16-QAM modulations on the AWGN channel show marked improvement over previously reported raptor code designs.
Keywords :
AWGN channels; binary codes; error correction codes; linear programming; quadrature amplitude modulation; quadrature phase shift keying; 16-QAM modulations; 1D EXIT chart; AWGN channels; BICM; QPSK; binary modulations; check-node degree distribution optimization; higher-order modulations; linear program; pre-code error-correcting capability; pre-code rates; raptor codes; standard Gray-mapped constellations; AWGN channels; Channel capacity; Collaboration; Decoding; Design methodology; Modulation coding; Quadrature phase shift keying; Redundancy; Robustness; Throughput;
Conference_Titel :
Military Communications Conference, 2009. MILCOM 2009. IEEE
Conference_Location :
Boston, MA
Print_ISBN :
978-1-4244-5238-5
Electronic_ISBN :
978-1-4244-5239-2
DOI :
10.1109/MILCOM.2009.5380125
