Design of improved error-rate sliding window decoder for SC-LDPC codes: reliable termination and channel value reuse

Abstract

In this paper, an improved error-rate sliding window decoder is proposed for spatially coupled low-density parity-check (SC-LDPC) codes. For the conventional sliding window decoder, the message retention mechanism causes unreliable messages along the edges of belief propagation (BP) decoding in the current window to be kept for subsequent window decoding. To improve the reliability of the retained messages during the window transition, a reliable termination method is embedded, where the retained messages undergo more reliable parity checks. Additionally, decoding failure is unavoidable and even causes error propagation when the number of errors exceeds the error-correcting capability of the window. To mitigate this problem, a channel value reuse mechanism is designed, where the received channel values are utilized to reinitialize the window. Furthermore, considering the complexity and performance of decoding, a feasible sliding optimized window decoding (SOWD) scheme is introduced. Finally, simulation results confirm the superior performance of the proposed SOWD scheme in both the waterfall and error floor regions. This work has great potential in the applications of wireless optical communication and fiber optic communication.

Keywords

A

References

[1] Jahid A, Alsharif M H, Hall T J. A contemporary survey on free space optical communication: potentials, technical challenges, recent advances and research direction[J]. Journal of network and computer applications. 2022, 200: 103311

[2] Youssef A A, Abaza M, Alatawi A S. LDPC decoding techniques for free-space optical communications[J]. IEEE access. 2021, 9: 133510-133519

[3] Sun X, Djordjevic I B. FPGA implementation of rate-adaptive spatially coupled LDPC codes suitable for optical communications[J]. Optics express. 2019, 27(3): 3422-3428

[4] Ima X, Ma X, Shan Y. Improved forward error correction technology of RS-LDPC cascade code in optical transport network[J]. Optoelectronics letters. 2023, 19(10): 593-598

[5] Zhang X, Xuan Y, Gong Z, et al. . Experimental demonstration of flexible information rate PON beyond 100 Gb/s with rate-compatible LDPC codes[J]. Optics express. 2024, 32(9): 15444-15459

[6] Djordjevic I B, Vasic B. MacNeish-Mann theorem based iteratively decodable codes for optical communication systems[J]. IEEE communications letters. 2004, 8(8): 538-540

[7] Milenkovic O, Djordjevic I B, Vasic B. Block-circulant low-density parity-check codes for optical communication systems[J]. IEEE journal of selected topics in quantum electronics. 2004, 10(2): 294-299

[8] Kudekar S, Richardson T J, Urbanke R L. Threshold saturation via spatial coupling: why convolutional LDPC ensembles perform so well over the BEC[J]. IEEE transactions on information theory. 2011, 57(2): 803-834

[9] Mitchell D G, Lentmaier M, Costello D J. Spatially coupled LDPC codes constructed from protographs[J]. IEEE transactions on information theory. 2015, 61(9): 4866-4889

[10] Golmohammadi A, Mitchell D G. Concatenated spatially coupled LDPC codes with sliding window decoding for joint source-channel coding[J]. IEEE transactions on communications. 2021, 70(2): 851-864

[11] Iyengar A R, Papaleo M, Siegel P H, et al. . Windowed decoding of protograph-based LDPC convolutional codes over erasure channels[J]. IEEE transactions on information theory. 2011, 58(4): 2303-2320

[12] Iyengar A R, Siegel P H, Urbanke R L, et al. . Windowed decoding of spatially coupled codes[J]. IEEE transactions on information theory. 2012, 59(4): 2277-2292

[13] Hassan N U, Pusane A E, Lentmaier M, et al. . Non-uniform window decoding schedules for spatially coupled LDPC codes[J]. IEEE transactions on communications. 2016, 65(2): 501-510

[14] Sun X, Djordjevic I B. FPGA implementation of rate-adaptive spatially coupled LDPC codes suitable for optical communications[J]. Optics express. 2019, 27(3): 3422-3428

[15] Zhu K, Wu Z. Comprehensive study on CC-LDPC, BC-LDPC and polar code[C]. 2020 IEEE Wireless Communications and Networking Conference Workshops (WCNCW), April 6–9, 2020, Seoul, Korea (South). 2020, New York, IEEE: 16

[16] Ali I, Kim J H, Kim S H, et al. . Improving windowed decoding of SC LDPC codes by effective decoding termination, message reuse, and amplification[J]. IEEE access. 2017, 6: 9336-9346

[17] Kang P, Xie Y, Yang L, et al. . Reliability-based windowed decoding for spatially coupled LDPC codes[J]. IEEE communications letters. 2018, 22(7): 1322-1325

[18] Zhu M, Mitchell D G, Lentmaier M, et al. . Error propagation mitigation in sliding window decoding of braided convolutional codes[J]. IEEE transactions on communications. 2020, 68(11): 6683-6698

[19] Zhu M, Mitchell D G, Lentmaier M, et al. . Systematic doping of SC-LDPC codes[C]. 2022 IEEE International Symposium on Information Theory (ISIT), June 26–July 1, 2022, Espoo, Finland. 2022, New York, IEEE: 536541

[20] Lian Q, Chen Q, Zhou L, et al. . Adaptive decoding algorithm with variable sliding window for double SC-LDPC coding system[J]. IEEE communications letters. 2022, 27(2): 404-408

[21] Kim J, Joo H G, Shin D J. Effective bi-directional overlapped sliding window decoding of SC-LDPC codes[J]. ICT express. 2023

RIGHTS & PERMISSIONS

Tianjin University of Technology