Advanced Television Research Articles

A Deep Learning-Based Emergency Alert Wake-Up Signal Detection Method for the UHD Broadcasting System.

With the increasing frequency and severity of disasters and accidents, there is a growing need for efficient emergency alert systems. The ultra-high definition (UHD) broadcasting service based on Advanced Television Systems Committee (ATSC) 3.0, a leading terrestrial digital broadcasting system, offers such capabilities, including a wake-up function for minimizing damage through early alerts. In case of a disaster situation, the emergency alert wake-up signal is transmitted, allowing UHD TVs to be activated, enabling individuals to receive emergency alerts and access emergency broadcasting content. However, conventional methods for detecting the bootstrap signal, essential for this function, typically require an ATSC 3.0 demodulator. In this paper, we propose a novel deep learning-based method capable of detecting an emergency wake-up signal without the need for an ATSC 3.0. The proposed method leverages deep learning techniques, specifically a deep neural network (DNN) structure for bootstrap detection and a convolutional neural network (CNN) structure for wake-up signal demodulation and to detect the bootstrap and 2 bit emergency alert wake-up signal. Specifically, our method eliminates the need for Fast Fourier Transform (FFT), frequency synchronization, and interleaving processes typically required by a demodulator. By applying a deep learning in the time domain, we simplify the detection process, allowing for the detection of an emergency alert signal without the full suite of demodulator components required for ATSC 3.0. Furthermore, we have verified the performance of the deep learning-based method using ATSC 3.0-based RF signals and a commercial Software-Defined Radio (SDR) platform in a real environment.

Progress Report of the Advanced Television Systems Committee

Progress Report of the Advanced Television Systems Committee

Implementation of Wireless Backhaul and Inter-Tower Communications With MIMO in ATSC 3.0

Wireless backhaul, i.e., in-band distribution links (IDL) and inter-tower communications networks (ITCN) were previously proposed as key enabling technologies for the next-generation digital broadcasting systems, e.g., the Advanced Television Systems Committee (ATSC) 3.0 system. Both ITCN/IDL can be operated in the spectrum-efficient in-band full-duplex (IBFD) mode and the same frequency band is shared between the broadcast service signal and the ITCN/IDL signals. It is desirable to integrate multi-input multi-output (MIMO) into ITCN/IDL transmission to increase the throughput and reduce the portion of spectrum occupation by ITCN/IDL. However, due to the backward compatibility constraint, conventional symmetrical MIMO techniques cannot be applied directly to the existing broadcast infrastructure without affecting legacy receivers. In this paper, the practical implementation of a non-symmetrical MIMO for ITCN/IDL while maintaining backward compatibility is considered. In addition to the existing broadcasting antenna, the non-symmetrical MIMO comprises an additional low-power RF feeder cable and one or more highly directional antennas to achieve low-cost MIMO implementation for high throughput data distribution and inter-tower communications. When the broadcast service signal and the MIMO signal are multiplexed in Time Division Multiplexing (TDM) format, the signal structure is ATSC 3.0 standard compliant. When the broadcast service signal and the MIMO signal are multiplexed in Layer Division Multiplexing (LDM) format, modification of the ATSC 3.0 standard, i.e., introducing a new pilot encoding scheme, is required. Moreover, MIMO self-interference cancellation (SIC) is investigated for IBFD operation.

Time Synchronization and Signal Detection in Non-Orthogonal Unicast and Broadcast Networks

The next generation digital TV (DTV) broadcast, namely Advanced Television System Committee (ATSC) 3.0, relies on substantial single frequency networks (SFN), each of which requires a studio to transmitter link (STL) to transmit data from the broadcast gateway (BG), leading to significant construction costs. Therefore, the wireless in-band distribution link (IDL) technology is proposed, which uses layered-division multiplexing (LDM) to transmit the STL data via wireless links from the BG to the SFN transmitters within the same spectrum as the broadcast services. In this paper, we propose the time synchronization and signal detection algorithm for wireless IDL systems with both unicast and broadcast signals. We introduce two multiplexing schemes, N-LDM and 3-LDM, and demonstrate their superiority over traditional frequency division multiplexing (FDM). To overcome the challenge of multi-access interference and synchronization errors caused by multipath, we develop a unique word (UW) design algorithm for transmitted signals and a double threshold correlation detection algorithm (DTCDA) that outperforms traditional ones. We employ a second threshold to enhance detection performance at low signal-to-noise ratios, and utilizes successive interference cancellation (SIC) to mitigate multiple-access interference. More importantly, our approach requires no knowledge of the unicast user number or channel state information. Simulation results validate the effectiveness of the proposed scheme.

In-Band Full-Duplex Communications in ATSC 3.0 Single Frequency Network

Wireless in-band backhaul, a.k.a. in-band distribution links (IDL), is a spectrum-efficient and cost-effective enabling technology to the realization of Advanced Television Systems Committee (ATSC) 3.0 in the single frequency network (SFN) mode, where all the transmitter towers are synchronized to transmit the same broadcast signal in the same frequency band. Inter-tower communications network (ITCN) transforms the broadcast towers into a mesh network, thereby introducing datacasting capability to the traditional broadcast network. Both the ITCN and IDL can be operated in the most spectrum-efficient in-band full-duplex (IBFD) mode. In these situations, the ITCN/IDL receivers at the SFN towers receive the signal of interest (SOI) not only severely corrupted by the self-interference signal from its co-located transmitter, but also the co-channel interference signals from neighbouring transmitters. Moreover, the ITCN/IDL signals may be combined with the broadcast signal in the Layer Division Multiplexing (LDM) format to achieve better overall spectral efficiency. Therefore, the LDM inter-layer interference must also be mitigated. In this paper, the interferences for the ITCN/IDL signal in the SFN environment are analyzed, and a novel iterative successive signal cancellation scheme is proposed to effectively mitigate the interferences in the ITCN/IDL signal detection process in ATSC 3.0 SFNs.

ATSC 3.0, DVB-I, and TV 3.0 Services via 5G Broadcast—System Design and Reference Tools

5G broadcast brings the promise of an independent or complementary linear TV experience, which can reuse existing terrestrial broadcast infrastructure to serve high definition (HD) or 4K live content to mobile devices, possibly independent of a mobile subscription. To benefit fully from this new capability, the design of a service layer is essential, including service discovery procedures and delivery protocols over IP multicast. This article examines the set of the different standardized service layers brought by the 3GPP, Advanced Television Systems Committee (ATSC), and Digital Video Broadcasting (DVB), which could target different regions, ecosystems, or regulatory requirements. To support media service providers, a full ecosystem of tools is now emerging, including the Reference Tools from the 5G Media Action Group (5G-MAG) and the GPAC open-source solution. We will introduce the consolidated work from 3GPP and 5G-MAG to make this vision a reality, in terms of standardization and development of reference tools. We will detail how DVB-I services over 5G broadcast can now be experimented with commodity tools and commercial devices. We will also identify the potential synergies with ATSC 3.0 A/3311and the possibilities for Brazil’s TV 3.0 project,2for which Real-time Object delivery over Unidirectional Transport (ROUTE)/dynamic adaptive streaming over HTTP (DASH) is the transport layer of choice and 5G broadcast is a candidate for the physical layer.

Progress Report of the Advanced Television Systems Committee

This report summarizes work currently underway in the Advanced Television Systems Committee (ATSC) relating to technical standards for ATSC 3.0.

Implementation and test results of on‐channel repeater for ATSC 3.0 systems

Despite the successful launch of Advanced Television Systems Committee (ATSC) 3.0 broadcasting worldwide, broadcasters are facing obstacles in constructing void-less large-scale single-frequency networks (SFNs). The bottleneck is the absence of decent on-channel repeater (OCR) solutions necessary for SFNs. In the real world, OCRs suffer from the maleficent feedback interference (FI) problem, which overwhelms the desired input signal. Moreover, the undesired multipaths between studio-linked transmitters and the OCR deteriorate the forward signals' quality as well. These problems crucially restrict the feasibility of conventional OCR systems, arousing the strong need for cost-worthy advanced OCR solutions. This paper presents an ATSC 3.0-specific solution of advanced OCR that solves the FI problem and refines the input signal. To this end, the FI canceler and channel equalizer functionalities are carefully implemented into the OCR system. The presented OCR system is designed to be fully compliant with the ATSC 3.0 specifications and performs a fast and efficient signal processing by exploiting the specific frame structure. The real product of ATSC 3.0 OCR is fabricated as well, and its feasibility is verified via field and laboratory experiments. The implemented solution is installed at a commercial on-air site and shown to provide substantial coverage gain in practice.

An Improved SIC-Based Detection Scheme for Non-Uniform Constellations in ATSC 3.0 MIMO

This paper presents an alternative approach to real-valued signal representation and proposes an improved successive interference cancellation (SIC)-based detection scheme using the alternative signal representation for non-uniform constellations (NUCs) in Advanced Television Systems Committee (ATSC) 3.0. Since I/Q polarization interleaving in ATSC 3.0 multiple-input multiple-output (MIMO) precoding performs a non-linear operation, it makes it difficult to use conventional suboptimal detection schemes based on interference cancellation. Therefore, the alternative signal representation is designed to easily apply various suboptimal detection schemes. Further, to obtain more robustness and lower complexity, a suboptimal detection scheme based on the alternative signal representation and interference cancellation with QR decomposition is proposed. The proposed detection scheme exploits the structural properties of NUCs and jointly detects the real and imaginary parts as a block. In addition, by considering one or more candidate symbols in the interference cancellation for the proposed detection scheme, the performance and the complexity are trade-offs according to the number of the considering candidate symbols. Simulation results show that the proposed detection scheme with a slight increase of the complexity significantly outperforms a linear detection under fixed and mobile channels.

Converged Distribution of 5G Media: Opportunities of Overlaid Broadcast and Emerging Applications Over Dual Connectivity

This paper encompasses various topics for 5G-involved broadcasting under the common context converged distribution of 5G media. Particularly, two primary subtopics are addressed: An overlaid coexistence of 5G terrestrial broadcast and Advanced Television Systems Committee (ATSC) 3.0; and dual connectivity applications built on top of the convergence between digital broadcasting and 5G unicasting. In the first part, a viable, time-sharing co-transmission system is introduced to overlay 5G Broadcast and ATSC 3.0 frames in the same radio spectrum. The system is carefully designed to comply with current 5G and ATSC 3.0 standards, so that it does not require modifications in either ATSC 3.0 or 5G specifications. To help the future planning in a technical aspect, the reliability performance is in-depth compared between 5G Broadcast and ATSC 3.0 frames, and the motivation of tower overlaying is discussed as well. Subsequently in the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2^{\mathrm{ nd}}$ </tex-math></inline-formula> part, the convergence is in parallel explored with respect to the dual connectivity. To settle a broad-ranged consensus for future convergence, various possible use cases are proposed in an application aspect. Technical, conceptual proposals and implementations are presented, specifically related to edge caching; 8K streaming (with a working prototype); large-scale software updating; data security; and location tracking. We hereby point out how dual connectivity can contribute to realistic scenarios. In turn, the scope of convergence use cases is desirably expanded, so that would encourage the initiatives bridging 5G and broadcasting into practice.

Estimation of channel MSE for ATSC 3.0 receiver and its applications

In this paper, we propose a method to estimate the mean square error (MSE) of the estimated channel for ATSC (Advanced Television Systems Committee) 3.0 systems. When combining the channel MSE and noise variance, we can better estimate the a priori LLR (log likelihood ratio) for the sum–product algorithm. The experimental results show that doing so yields better BER (bit error rate) performance in the 0 dB echo channel. The improvement in the 2-D channel estimation is about 0.2 dB. In the 1-D estimation case, the proposed approach is essential to decode codewords.

Effective identification of dominant fully absorbing sets for Raptor‐like LDPC codes

AbstractThe error‐rate floor of low‐density parity‐check (LDPC) codes is attributed to the trapping sets of their Tanner graphs. Among them, fully absorbing sets dominantly affect the error‐rate performance, especially for short blocklengths. Efficient methods to identify the dominant trapping sets of LDPC codes were thoroughly researched as exhaustively searching them is NP‐hard. However, the existing methods are ineffective for Raptor‐like LDPC codes, which have many types of trapping sets. An effective method to identify dominant fully absorbing sets of Raptor‐like LDPC codes is proposed. The search space of the proposed algorithm is optimized into the Tanner subgraphs of the codes to afford time‐efficiency and search‐effectiveness. For 5G New Radio (NR) base graph (BG) 2 LDPC codes for short blocklengths, the proposed algorithm finds more dominant fully absorbing sets within one seventh of the computation time of the existing search algorithm, and its search‐effectiveness is verified using importance sampling. The proposed method is also applied to 5G NR BG1 LDPC code and Advanced Television Systems Committee 3.0 type A LDPC code for large blocklengths.

Field Evaluation of Transmit Diversity Code Filter Sets in ATSC 3.0 Single Frequency Networks

Advanced Television Systems Committee (ATSC) 3.0, a recently developed terrestrial broadcasting standard, supports a Single Frequency Network (SFN), which extends service coverage and enhances received field strength without additional frequency resources. In SFN, multiple transmitters emit identical ATSC 3.0 broadcasting signals, which may cause constructive or destructive interference on a receiver side. The worst situation occurs when two signals from different transmitters are received with the opposite phase and similar power within a sample time, causing the cancellation of the received signal. In order to prevent such signal cancellation, ATSC 3.0 adopted transmitter diversity code filter sets (TDCFS), which is a frequency domain pre-distortion scheme to minimize cross-correlation among multiple transmitter signals in SFN. This paper sets up an ATSC 3.0 SFN consisting of two transmitter sites, transmitting high definition (HD) for mobile service and 4K ultra high definition (UHD) for fixed service. Layered division multiplexing (LDM) and time division multiplexing (TDM) are used to simulcast the two services with different robustness in the same radio frequency (RF) channel. Then, performance is evaluated using a threshold of visibility (ToV) and a successful reception rate. The time and frequency channel responses are changed at the same reception area when TDCFS is applied so the results show that reception performance is improved in the worst situation in SFN.

A Polygonal Line Min-Sum Decoding Scheme for Low Density Parity Check Codes

Low-density parity-check (LDPC) codes are widely used as error correction codes in new generation digital TV standards, such as the second generation of terrestrial digital video broadcasting standard (DVB-T2), Advanced Television Systems Committee (ATSC) 3.0, etc. The nonlinear belief propagation (BP) algorithm has excellent decoding performance for LDPC codes, but is often simplified in hardware implementations by linear min-sum (MS) algorithm due to its high complexity. This simplification also leads to over-estimation problems, which can be corrected by adding factors in conventional algorithms (e.g., normalized min-sum (NMS), offset min-sum (OMS), and variable scaling normalized min-sum (VMS) algorithms). However, the correction factors of these modified MS algorithms cannot adapt to different channels and modulations, and the performance needs further improvement. In this paper, the concepts of over-estimation value (OEV) and over-estimation rate (OER) are introduced to describe the over-estimation problem of the MS algorithm. Then, under the guidance of OEV and OER, a polygonal line min-sum (PMS) algorithm with correction factors adapted to different channels and modulations is proposed according to LLR distribution. Following the properties of OEV and OER, PMS algorithm is further simplified into Simplified PMS (SPMS) algorithm. LDPC codes from ATSC 3.0 are adopted in this paper to evaluate SPMS algorithm in comparison with the conventional algorithms. Extensive simulation results show that the SPMS algorithm for ATSC 3.0 LDPC decoder has at most 1.61dB, 0.24dB and 0.36dB gain over NMS, OMS and VMS algorithms respectively when frame error rate (FER) is at 10⁻⁴ level over additive white Gaussian noise (AWGN) channel with QPSK modulation. More importantly, the simulation results show that the SPMS algorithm can achieve much better performance than these modified MS algorithms over AWGN and Rayleigh channel with higher-order modulations or under limited maximum iteration number.

MPEG-H Audio System for SBTVD TV 3.0 Call for Proposals

Under the name “TV 3.0 Project”, the Brazilian Terrestrial Television System Forum (SBTVD) has issued the Call for Proposals (CfP) for a next generation Brazilian digital TV system, in July 2020. The MPEG-H Audio system, based on the open international standard ISO/IEC 23008-3, has been proposed by Fraunhofer IIS, ATEME, the Digital Broadcasting Experts Group (DiBEG) and the Advanced Television Systems Committee (ATSC). This paper provides an overview of the MPEG-H Audio system and the TV 3.0 Project requirements for the audio component. The TV 3.0 Project specifies a detailed test and evaluation procedure for verifying the fulfillment of the requirements. With wide industry support, the MPEG-H Audio system brings immersive sound, advanced interactivity, and accessibility options, as well as advanced features like hybrid delivery, consistent loudness after user interaction, connectivity options for external sound devices and seamless configuration changes. The MPEG-H Audio proponents have submitted a complete production and broadcast real-time chain to the SBTVD Forum which demonstrates the most advanced features.

A Novel Coordinated Multipoint Scheme With Zero Guard Interval for ATSC 3.0 Single Frequency Networks

Advanced Television Systems Committee (ATSC) has issued ATSC 3.0 as the standard for the next-generation of Digital Terrestrial Television (DTT) broadcasting. ATSC 3.0 introduces several new features including Layered Division Multiplexing (LDM) that is a form of Non-Orthogonal Multiple Access (NOMA). ATSC 3.0 supports the legacy Single Frequency Networks (SFN), where the Guard Interval (GI) is considered to overcome the multipath as well as the asynchronous reception from different transmitters. Considering the huge distances between the DTT broadcasters, the GI overhead could be comparable to the data size, making the control/data ratio unfavorable. This paper proposes the association of Coordinated MultiPoint (CoMP) in SFN with NOMA-LDM. A novel formation of the channel matrix is provided that jointly includes the asynchronous channel's cross correlations for further joint detection of the signals at the receiver. The purpose is to enhance the coverage and spectral efficiency while avoiding hectic guard intervals or directional antennas. The capacity region is derived in an information theoretic framework based on exploiting the asynchronous channels' memory and correlation. We show that the spectral efficiency can exceed that of the non-coordinating schemes, provided that the proper receiver is equipped with the proposed channel matrix formation. Our extensive simulations validate that our proposed association of CoMP-SFN with NOMA-LDM provides a considerable boost in the coverage and channel reliability, while increasing the spectral and power efficiency.

Progress Report of the Advanced Television Systems Committee

This report summarizes the work currently underway in the Advanced Television Systems Committee (ATSC) relating to technical standards for digital broadcasting.

Section Meetings

The Ohio Section meeting on 27 July was combined with the local Society of Broadcast Engineers (SBE) Chapter 52 and took place at the new Sinclair Broadcast Television transmitter plant in Columbus. Included within that plant are both Advanced Television Systems Committee (ATSC) 1.0 and ATSC 3.0 “Lighthouse” TV transmitters as well as radio transmission operations. The ATSC 3.0 TV broadcast transmitter is radically different in that it uses the Orthogonal Frequency Division Multiplexing (OFDM) signal standard rather than the 1.0 Zenith 8VSB type. On the air since 7 January 2021, their new TV transmitter can accommodate/passthrough up to five complete ATSC 3.0 stations’ signals, including those from other TV stations within the Columbus market, part of a temporary channel-sharing arrangement scenario. The sole purpose of this “Lighthouse” TV station is to broadcast all of the Columbus area TV stations’ ATSC 3.0 signals for up to five years after first launching their 3.0 broadcasts. After that initial five-year period, each station will continue their ATSC 3.0 broadcast services from their individual towers/antennas, and so on, after shutting down their legacy ATSC 1.0 broadcast signal operations.

Feasibility Verification of ATSC 3.0 MIMO System for 8K-UHD Terrestrial Broadcasting

This paper presents feasibility verification of the Advanced Television Systems Committee (ATSC) 3.0 MIMO system for 8K-UHD terrestrial broadcasting services. For a reliable performance evaluation, computer simulation, laboratory test, and field trial are conducted, and the tests’ results are compared with the same performance metrics. Several physical layer configurations with various data rates from 63 Mbps to 113 Mbps are verified. The field trial results confirm that the ATSC 3.0 MIMO system can support data rates up to 113 Mbps within a 6 MHz bandwidth.

Section Meetings

The March Toronto Section meeting titled “ATSC 3.0 in 2021” was held in March 2021 and moderated by SMPTE Toronto Section Chair, Tony Meerakker. Orest Sushko from the Humber Broadcast-Broadband Convergence Lab in Toronto opened the meeting. Humber has launched an initiative to create an environment for real-world ATSC 3.0 testing, with plans to aid in the analysis of various applications introduced into the broadcast radio frequency (RF) environment, including integration with 5G networks. They plan to drive the research into Advanced Television Systems Committee (ATSC) 3.0 adoption in Canada.