Girth aware normalized min sum decoding algorithm for shorter length low density parity check codes

Abstract

Recently, short block codes are in great demand due to the emergent applications requiring the transmission of a short data unit and can guarantee speedy communication, with a minimum of latency and complexity which are among the technical challenges in today’s wireless services and systems. In the context of channel coding using low density parity check (LDPC) codes, the shorter length LDPC block codes are more likely to have short cycles with lengths of 4 and 6. The effect of the cycle with the minimum size is that this one prevents the propagation of the information in the Tanner graph during the iterative process. Therefore, the message decoded by short block code is assumed to be of poor quality due to short cycles. In this work, we present a study of the evolution of the messages on check nodes during the iterative decoding process when using the LDPC decoding algorithm normalized min sum (NMS), to see the destructive effect of short cycles and justify the effectiveness of the girth aware normalized min sum (GA-NMS) decoding LDPC codes algorithm in terms of correction of the errors, particularly for the codes with short cycles 4 and 6. In addition to this, the GA-NMS algorithm is evaluated in terms of bit error rate performance and convergence behavior, using wireless regional area networks (WRAN) LDPC code, which is considered as a short block code.

Optimized decoder for low-density parity check codes based on genetic algorithms

“…As a reduction of the LLR BP method, [3] two sides of the min sum (MS) algorithm enable the implementation of soft decisions by replacing the tanh function with the minimal value at the expense of non-negligible performance loss. Several enhancements were proposed to close the disparity between both the BP algorithm and the MS approach [4]. Although the weighted BF (WBF) algorithm as well as the gradient descent BF (GDBF) have made significant progress over the soft decision decoding algorithm [5]- [9], but the gap between the two decoding methods is still there.…”

Deriving equivalent structure of elements for low density parity check codes construction

“…Low density parity-check (LDPC) codes are a class of linear block codes in which the complexity of iterative decoding increases linearly with block-length [4]. As a result, LDPC codes have near-Shannon Indonesian J Elec Eng & Comp Sci ISSN: 2502-4752 Ì 145 limit performance on long block-length data transmission [5].…”