Performance Analysis and Enhanced Chase Decoding of GII-BCH Codes

Generalized integrated interleaved (GII) codes enable an enhanced error-correction over an array of interleaves (component codes) within a single block. Error-correction performance of GII codes can be further improved by utilizing the soft received information. The existing Chase decoding of GII-BCH codes can achieve a significant coding gain over the hard-decision decoding, but at the cost of complexity. Meanwhile, the existing theoretical characterization of its Chase decoding performance remains complex and partially empirical. This paper introduces a new theoretical characterization for Chase decoding performance of GII-BCH codes. With this characterization, it further proposes two new soft-decision decoding methods for GII-BCH codes, including the enhanced Chase decoding (ECD) and the enhanced concatenated Chase decoding (ECCD). They both identify the decoding rounds that are more likely to declare a decoding failure and prioritize allocating the flipped positions to those rounds. In particular, the latter utilizes codewords of a linear block code to cover the least reliable or the second least reliable positions, further improving the error-correction performance over the ECD. With a similar number of test-vectors, both the ECD and ECCD can outperform the existing Chase decoding for GII-BCH codes.