1 Abstract—This paper proposes a backward compatible UHDTV transmission based on augmented data transmission (ADT) system for the ATSC terrestrial DTV broadcasting. The proposed system provides MPEG-2 DTV signal with a rate of 19.3 Mbps and HEVC-base ADT signal with a rate of about 7 Mbps. If we combine MPEG-2 DTV signal and HEVC-base ADT signal properly, we can provide 4K UHD video service as well as backward compatible HD video service simultaneously. Index Terms—Backward Compatibility, UHDTV, ADT I. INTRODUCTION As viewer’s desire for enjoying realistic and high-quality audio/video (AV) contents on larger screen has been increased, ultra-high definition television (UHDTV) broadcasting service seems to be a very hot topic in connection to the success of commercializing ultra-high definition (UHD) camera, display panel, etc. It is also convinced that most of viewers are eager to feel more realistic sense at home through bigger and detailed AV contents. Terrestrial broadcasting can be an economic way to meet such viewer’s demand, however, it is suffering from the lack of bandwidth to provide a next-generation TV service including UHDTV broadcasting. Minimum data rate of 4K UHDTV source video is 4.98 Gbps, which is around four times of current high definition (HD) video [1]. Therefore, for 4K UHDTV terrestrial broadcasting, it is indispensable not only to employ high efficiency video coding (HEVC), but also to optimize transmission efficiency at physical layer. Recently, there were a few trials to increase data capacity of This research was supported by the Ministry of Science, ICT and Future Planning, Rep. of Korea, under the support program supervised by the Korea Communications Agency (KCA) (Development of Terrestrial Broadcasting Technology for Next Generation DTV). S. I. Park, G. Lee, H. M. Kim, and N. Hur are with the Broadcasting System Research Department, Electronics and Telecommunications Research Institute, Daejeon, 305-700, Korea (e-mail: { psi76, gslee, hmkim, namho}@etri.re.kr). Y. Wu is with the Communications Research Centre Canada, 3701 Carling Ave., Ottawa, ON K2H 8S2 Canada (e-mail: yiyan.wu@crc.ca). J. Chung is with the School of Electrical and Computer Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Korea (e-mail: jinho@unist.ac.kr). J. Kim is with the Department of Electronics and Communications Engineering, Korea Maritime University, Busan 606-791, Korea (e-mail: jchkim@hhu.ac.kr). the existing ATSC terrestrial DTV system while guaranteeing backward compatibility [2-5]. In [2] and [3], a very low-rate data transmission scheme that uses the polarity of the transmitter identification (TxID) signal was developed. However, the achievable data rate of the scheme in [2] and [3] is at most approximately a few kbps. In order to increase such low data rate, the augmented data transmission (ADT) system was proposed and implemented in [4] and [5]. Since the ADT system uses a very low injection level and a low-rate low-density parity check (LDPC) code for not to degrade the performance of legacy DTV receivers, the practical data rate of the ADT system is limited up to 3 Mbps. However, if the performance degradation of legacy DTV receivers about a few dB is acceptable, the achievable data rate can be increased up to around 7 Mbps by using a higher injection level and a high-rate LDPC code properly. In this paper, we exemplify a backward compatible UHDTV transmission based on ADT system for the ATSC terrestrial DTV broadcasting. The exemplified system provides MPEG-2 DTV signal with a rate of 19.3 Mbps and HEVC-base ADT signal with a rate of about 7 Mbps. If we combine MPEG-2 DTV signal and HEVC-base ADT signal properly, we can transmit UHDTV content while guaranteeing backward compatibility. II. ADT SYSTEM FOR THE ATSC TERRESTRIAL DTV BROADCASTING In [4] and [5], the ADT system increasing the data capacity of the existing ATSC terrestrial DTV system was proposed and implemented. The implemented ADT system can provide an additional data rate of up to 3 Mbps based on hierarchical modulation, DTV signal cancellation, and advanced error correction techniques. Fig. 1 shows the ADT transmitter and receiver structures. The ADT channel encoded additional data are hierarchically injected to the legacy 8-level DTV symbols with a very low bury ratio (BR) before a pilot insertion, and then transmitted through the vestigial sideband (VSB) modulation. The received ADT signal is VSB demodulated, and then equalized to compensate channel distortions. After equalization, the DTV signal canceler subtracts the DTV signal, which is the output of the DTV signal detector, from the equalized ADT signal to remove the large interference from the Backward Compatible UHDTV Transmission based on ADT System for the ATSC Terrestrial DTV Broadcasting Sung Ik Park, Member, IEEE, Gwangsoon Lee, Yiyan Wu, Fellow, IEEE, Heung Mook Kim, Member, IEEE, Namho Hur, Member, IEEE, Jin-Ho Chung, Member, IEEE, and Jeongchang Kim, Member, IEEE