A syndrome-based LDPC decoder with very low error floor

This work improves the performance of LDPC decoders that implement iterative algorithms dominated by oscillatory behavior - such as offset Min-Sum algorithm - in cases of unsuccessful decoding of received words. The proposed LDPC decoder is applied on the decoding procedure of an LDPC algorithm by selecting the one of the N different estimated codewords (each produced at an iteration of the decoder) that corresponds to the syndrome with the minimum number of unsatisfied check constraints, as the output of the decoder. This method provides a decoder that achieves a notable performance improvement in the error floor region of operation for the offset Min-Sum decoding algorithm, with an insignificant increase of the hardware complexity.