Abstract
We consider linear programming (LP) decoding of a fixed low-density parity-check (LDPC) code over the binary symmetric channel (BSC). The LP decoder fails when it outputs a pseudo-codeword which is not equal to the transmitted codeword. We design an efficient algorithm termed the Instanton Search Algorithm (ISA) which generates an error vector called the BSC-instanton. We prove that: (a) the LP decoder fails for any error pattern with support that is a superset of the support of an instanton; (b) for any input, the ISA outputs an instanton in the number of steps upper-bounded by twice the number of errors in the input error vector. We then find the number of unique instantons of different sizes for a given LDPC code by running the ISA sufficient number of times.
Original language | English (US) |
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Article number | 5895058 |
Pages (from-to) | 4417-4426 |
Number of pages | 10 |
Journal | IEEE Transactions on Information Theory |
Volume | 57 |
Issue number | 7 |
DOIs | |
State | Published - Jul 2011 |
Keywords
- Binary symmetric channel (BSC)
- error-floor
- linear programming decoding
- low-density parity-check (LDPC) codes
- pseudo-codewords
ASJC Scopus subject areas
- Information Systems
- Computer Science Applications
- Library and Information Sciences