This paper introduces a family of error-correcting codes called zigzag codes. A zigzag code
is described by a highly structured zigzag graph. Due to the structural properties of the
graph, very low-complexity soft-in/soft-out decoding rules can be implemented. We present a
decoding rule, based on the Max-Log-APP (MLA) formulation, which requires a total of only
20 addition-equivalent operations per information bit, per iteration. Simulation of a rate-1/2
concatenated zigzag code with four constituent encoders with interleaver length 65 536 …

This paper introduces a family of error-correcting codes called zigzag codes. A zigzag code
is described by a highly structured zigzag graph. Due to the structural properties of the
graph, very low-complexity soft-in, soft-out decoding rules can be implemented. We present
a decoding rule, based on the Max-Log-MAP (MLM) formulation, which requires a total of
only 20 addition-equivalent-operations per information bit, per iteration. Simulation of a rate-
1/2, four-dimensional concatenated zigzag code with interleaver length 65536 yields a bit …