This article has been accepted for inclusion in a future issue of this journal. Content is final as presented, with the exception of pagination. IEEE TRANSACTIONS ON BROADCASTING 1 Comparison of Low-Density Parity-Check Codes in ATSC 3.0 and 5G Standards Seok-Ki Ahn , Kyung-Joong Kim, Seho Myung, Sung-Ik Park , Senior Member, IEEE, and Kyeongcheol Yang , Senior Member, IEEE Abstract—Recently, low-density parity-check (LDPC) codes have been adopted in Advanced Television Systems Committee 3.0 and 3rd Generation Partnership Project 5G standards. In this paper, we present their structures in detail. They are delicately designed, based on the structures of quasi-cyclic LDPC codes and multi-edge type LDPC codes. The differences in their base matrices and parity-check matrices used in both standards are highlighted from the viewpoint of the distinction between broad- casting and cellular communication systems. Numerical results show that they are very competitive in their respective areas. Index Terms—ATSC 3.0, 3GPP 5G, low-density parity- check (LDPC) codes, quasi-cyclic LDPC codes, multi-edge type LDPC codes. I. I NTRODUCTION I N 2016, the Advanced Television Systems Committee (ATSC) approved the physical layer stan- dard for the next generation digital terrestrial television systems [1]–[3]. During the evolution of terrestrial broadcast- ing standards from Digital Video Broadcasting via Satellite (DVB-S) to DVB-next generation handheld (DVB-NGH) and from ATSC 1.0 to ATSC 3.0, a lot of innovative technologies have been introduced and adopted to support efficiency and robustness. One of the innovative physical layer technologies is to employ low-density parity-check (LDPC) codes for forward error correction (FEC). Since LDPC codes were first adopted in the DVB-S2 standard, many continuous efforts have been made to improve their performance and optimize them up to the latest broadcasting standard, ATSC 3.0 [4]–[6]. Manuscript received July 27, 2018; revised September 18, 2018; accepted September 19, 2018. This work was supported in part by the National Research Foundation of Korea under grant funded by the Ministry of Science and ICT (MSIT) of the Korea Government (2016R1A2A1A05005023), and in part by the Institute for Information and Communications Technology Promotion (IITP) under grant funded by the MSIT of the Korea Government (2018(2016-0-00123)). (Corresponding author: Kyeongcheol Yang.) S.-K. Ahn, K.-J. Kim, and S. Myung are with the Network Business, Samsung Electronics Company, Ltd., Suwon 16677, South Korea (e-mail: seokki.ahn@gmail.com; kjoong.kim@gmail.com; seho78.myung@ gmail.com). S.-I. Park is with the Broadcasting Systems Research Department, Electronics and Telecommunications Research Institute, Daejeon 34129, South Korea (e-mail: psi76@etri.re.kr). K. Yang is with the Department of Electrical Engineering, Pohang University of Science and Technology, Pohang 37673, South Korea (e-mail: kcyang@postech.ac.kr). Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/TBC.2018.2874541 On the other hand, turbo codes, which were first adopted as an error-correcting code in the 3rd generation partnership project (3GPP) standard, have been used for cellular commu- nication systems until the 4G LTE standard [7]. During the recent standardization process of 5G, which develops the fun- damental technologies of 3GPP Release 15, they were also considered as a candidate for channel coding, together with LDPC codes and polar codes [8]. These codes were competed with each other in the aspects of performance, complexity, and flexibility, etc. As a result, LDPC codes were eventually adopted as one of the standards for channel coding in 5G [9], thanks to their excellent advantage in supporting very-high data throughput with low complexity. LDPC codes, which were first introduced in 1963 [10], have been extensively studied as one of modern error-correcting codes for the last two decades. They have been adopted in both ATSC 3.0 and 5G due to their capacity-approaching performance and low-complexity parallel decoding suitable for hardware implementation. Hence, they can be regarded as the most promising channel coding scheme in commercial systems, even though the requirements for broadcasting and cellular communication systems are different in general. Broadcasting systems usually require quasi error-free performance (for example, block error rate (BLER) ≤ 10 -6 ), and therefore, they employ LDPC codes of very long length (for example, 16,200 and 64,800 in both DVB-T2/S2 and ATSC 3.0) for both mobile and fixed services. The size of payload in these systems needs not to be dynamically changed as well as the number of the required code rates can be limited because the operating code rates are generally determined in advance according to the deployment environ- ments. Due to these reasons, the ATSC 3.0 standardization has focused on improving the performance of LDPC codes for the fixed combinations of code lengths and rates. However, the newly designed LDPC codes for the ATSC 3.0 standard have the same basic structure as that of the LDPC codes employed in conventional broadcasting standards. A few struc- tural constraints coming from the continuity of the standards sometimes make it difficult for newly designed LDPC codes to achieve the best performance. The LDPC codes adopted in the ATSC 3.0 standard will be named as ATSC-LDPC codes in this paper. In the 5G standard, various requirements are given to support several services, such as enhanced mobile broad- band (eMBB), ultra-reliable and low latency (URLLC), and massive machine type communications (mMTC). In [11], 0018-9316 c  2018 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission. See http://www.ieee.org/publications_standards/publications/rights/index.html for more information.