A1 R.K. Bhattar

A1 K.R. Ramakrishnan

A1 K.S. Dasgupta

PB iet

T1 Performance improvement of short-length regular low-density parity-check codes with low-complexity post-processing

JN IET Communications

VO 6

IS 15

SP 2487

OP 2496

AB It is well known that extremely long low-density parity-check (LDPC) codes perform exceptionally well for error correction applications, short-length codes are preferable in practical applications. However, short-length LDPC codes suffer from performance degradation owing to graph-based impairments such as short cycles, trapping sets and stopping sets and so on in the bipartite graph of the LDPC matrix. In particular, performance degradation at moderate to high Eb/N0 is caused by the oscillations in bit node a posteriori probabilities induced by short cycles and trapping sets in bipartite graphs. In this study, a computationally efficient algorithm is proposed to improve the performance of short-length LDPC codes at moderate to high Eb/N0. This algorithm makes use of the information generated by the belief propagation (BP) algorithm in previous iterations before a decoding failure occurs. Using this information, a reliability-based estimation is performed on each bit node to supplement the BP algorithm. The proposed algorithm gives an appreciable coding gain as compared with BP decoding for LDPC codes of a code rate equal to or less than 1/2 rate coding. The coding gains are modest to significant in the case of optimised (for bipartite graph conditioning) regular LDPC codes, whereas the coding gains are huge in the case of unoptimised codes. Hence, this algorithm is useful for relaxing some stringent constraints on the graphical structure of the LDPC code and for developing hardware-friendly designs.

K1 a posteriori probabilities

K1 code rate

K1 trapping set

K1 graph-based impairment

K1 BP algorithm

K1 coding gain

K1 error correction

K1 BP decoding

K1 decoding failure

K1 short-length regular low-density parity-check code

K1 LDPC matrix

K1 reliability-based estimation

K1 bit node

K1 bipartite graph

K1 belief propagation algorithm

K1 short-length LDPC code

K1 oscillation

K1 performance degradation

K1 low-complexity postprocessing

DO https://doi.org/10.1049/iet-com.2011.0292

UL https://digital-library.theiet.org/;jsessionid=1heiujvdh4p8v.x-iet-live-01content/journals/10.1049/iet-com.2011.0292

LA English

SN 1751-8628

YR 2012

OL EN