Performance Comparison of LDPC Block and Spatially Coupled Codes Over GF (q)

• Published in: IEEE transactions on communications Vol. 63; no. 3; pp. 592 - 604
• Main Authors: Kechao Huang, Mitchell, David G. M., Lai Wei, Xiao Ma, Costello, Daniel J.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.03.2015; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Binary system; Block codes; Blocking; Codes; Complexity; Computation; Computational complexity; Decoding; Decoding latency; Error correcting codes; Iterative decoding; Joining; LDPC block codes; LDPC codes; LDPC convolutional codes; Low density parity check codes; Pipelines; protograph-based codes; q-ary; Rule based; spatially coupled codes; protograph-based codes; LDPC convolutional codes; LDPC block codes; q-ary LDPC codes; Decoding latency; spatially coupled codes
• ISSN: 0090-6778; 1558-0857
• DOI: 10.1109/TCOMM.2015.2397433

In this paper, we compare the finite-length performance of protograph-based spatially coupled low-density paritycheck (SC-LDPC) codes and LDPC block codes (LDPC-BCs) over GF(q). To reduce computational complexity and latency, a sliding window decoder with a stopping rule based on a soft belief propagation (BP) estimate is used for the q-ary SC-LDPC codes. Two regimes are considered: one when the constraint length of q-ary SC-LDPC codes is equal to the block length of q-ary LDPC-BCs and the other when the two decoding latencies are equal. Simulation results confirm that, in both regimes, (3,6)-, (3,9)-, and (3,12)-regular non-binary SC-LDPC codes can significantly outperform both binary and non-binary LDPC-BCs and binary SC-LDPC codes. Finally, we present a computational complexity comparison of q-ary SC-LDPC codes and q-ary LDPC-BCs under equal decoding latency and equal decoding performance assumptions.