Designing LDPCCodeswithout small trapping sets byusing Tanner GraphCovers

Shashi KiranChilappagari

Published Jan 1, 2007• 0 citations

Abstract

We present amethodforlowering theerror floor oflow-density parity check(LDPC)codes. ItisbasedonTanner graphcovers thatdonothavetrapping setsfromtheoriginal code. Theadvantages ofthemethodarethatitisuniversal, as itcanbeapplied toanyLDPC code/channel model/decoding algorithm anditimproves performance attheexpense of increasing thecodelength, without losing thecoderegularity, without changing thedecoding algorithm, and,undercertain conditions, without lowering thecoderate. We illustrate the methodbymodifying Tanner, MacKayandMargulis codesto improve performance onthebinary symmetric channel (BSC) undertheGallager B decoding algorithm.

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