Title :
Analysis of low-density parity-check codes for the Gilbert-Elliott channel
Author :
Eckford, Andrew W. ; Kschischang, Frank R. ; Pasupathy, Subbarayan
Author_Institution :
Edward S. Rogers Sr. Dept. of Electr. & Comput. Eng., Univ. of Toronto, Ont., Canada
Abstract :
Density evolution analysis of low-density parity-check (LDPC) codes in memoryless channels is extended to the Gilbert-Elliott (GE) channel, which is a special case of a large class of channels with hidden Markov memory. In a procedure referred to as estimation decoding, the sum-product algorithm (SPA) is used to perform LDPC decoding jointly with channel-state detection. Density evolution results show (and simulation results confirm) that such decoders provide a significantly enlarged region of successful decoding within the GE parameter space, compared with decoders that do not exploit the channel memory. By considering a variety of ways in which a GE channel may be degraded, it is shown how knowledge of the decoding behavior at a single point of the GE parameter space may be extended to a larger region within the space, thereby mitigating the large complexity needed in using density evolution to explore the parameter space point-by-point. Using the GE channel as a straightforward example, we conclude that analysis of estimation decoding for LDPC codes is feasible in channels with memory, and that such analysis shows large potential gains.
Keywords :
channel coding; channel estimation; decoding; hidden Markov models; memoryless systems; parity check codes; GE parameter space; Gilbert-Elliott channel; LDPC; SPA; channel-state detection; density evolution analysis; estimation decoding; hidden Markov memory; low-density parity-check code; memoryless channel; sum-product algorithm; Block codes; Communication system control; Degradation; Hidden Markov models; Iterative algorithms; Iterative decoding; Memoryless systems; Parity check codes; Performance analysis; Sparse matrices; Density evolution; Gilbert-Elliott channel; estimation-decoding; low-density parity-check codes;
Journal_Title :
Information Theory, IEEE Transactions on
DOI :
10.1109/TIT.2005.856934