Detailed ATSC 3.0 ‘Physical Layer’ Technical Proposals Being Evaluated
Representing a major milestone in the development of the next-generation broadcast standard, the Advanced Television Systems Committee (ATSC) has received 11 detailed technical proposals for the Physical Layer of the “ATSC 3.0” broadcast TV transmission standard.
The next big step in the process is a series of meetings in October where each respondent will be asked to give tutorial presentations to the ATSC Specialist Group that is evaluating the proposed systems.
While a wide range of technologies were proposed by respondents, there’s some commonality among many of them. Submissions are very detailed, and generally each of the submissions is hundreds of pages in length. They reflect the thinking of the best minds in the broadcast industry, and the ATSC salutes the many engineers and business people who have already invested significant resources to develop technologies for ATSC to evaluate.
Expected to move to “candidate standard” status over the next two years, ATSC 3.0 will be designed to include higher capacity to deliver Ultra High-Definition TV services, robust reception on mobile devices and improved spectrum efficiency.
The ATSC 3.0 Physical Layer will define the modulation and error coding technologies to provide a foundation for the next terrestrial broadcast system.
A primary goal of the ATSC 3.0 Physical Layer is to provide TV service to both fixed and mobile devices. Multiple types of TV receivers, including fixed devices (such as traditional living room and bedroom TV sets), handheld devices, vehicular screens and portable receivers will be considered in the work on ATSC 3.0. Spectrum efficiency and robust service will be key areas of evaluation. Increased data rates to support new services such as Ultra-High-Definition services will be considered.
Robustness of service for devices operating within the ATSC 3.0 service area should exceed that of current ATSC systems and that of cell phone and other wireless devices. Consideration will be given to technologies and proposals that enable a smooth transition from existing systems for both broadcasters and consumer.
Summaries of Responses to ATSC 3.0 Physical Layer Call for Proposals:
Coherent Logix and Sinclair Broadcasting
The Sinclair Broadcasting Group and Coherent Logix ATSC 3.0 Physical Layer proposal is driven by business requirements of Broadcasters (Television Broadcast Wireless Carriers) and the need to be technologically competitive. The system is built around software definable solutions available in the market today and provides the means to evolve as the market and needs change.
This Next Generation Broadcast Platform (NGBP) proposal provides a foundation to allow Broadcasters to address the opportunities for significantly higher revenues, rapidly changing market requirements, viewer habits, and integration into extended communication infrastructures. Our evolvable solutions have been carefully constructed to allow broadcasters to leverage technology and application innovation from a variety of other platforms including the Internet and wireless carriers. The proposal is based upon globally deployed mature technologies and standards in other telecommunications systems: 3GPP, ETSI, MPEG, IEEE, IETF, W3C and TIA.
The proposal introduces new concepts for Broadcasters. These new concepts include Broadcast Market Exchange (BMX), parameterized waveforms, carrier aggregation, Evolved Packet Core (EPC) management, Long Term Evolution (LTE) and LTE-A (Advanced). This is an all IP core network topology.
Of important note: the system design can support the “Emergency Services” for America’s First Responders Services envisioned as essential to our Nation’s security.
Communications Research Centre (CRC) and Electronics & Telecommunications Research Institute (ETRI)
This proposal presents several technologies for the ATSC 3.0 PHY Layer.
A layered transmission system, named Cloud Transmission, which uses spectrum overlay technologies to simultaneously transmit multiple program streams with different robustness for different services (mobile TV, HDTV/UHDTV) in one RF channel. The transmitted signal consists of several independent signals superimposed together at different injection levels to form a multi-layered signal. Each layer can have its own characteristics. The top layer, or Cloud Txn Layer, is the most robust one, which has a negative SNR system threshold value, and can be used for robust mobile service. The lower layer(s) can be used to provide fixed high data rate services, such as multiple HDTV and UHDTV. The spectrum overlay transmission has better time and spectrum diversity for better spectrum efficiency and flexibility. MIMO, time-frequency slicing and NU-QAM can also be used.
A transmission error mitigation structure and a rate-compatible LDPC code are designed for the top layer to achieve negative system threshold SNR, reduce the decoding complexity, save power, and decrease latency under different reception conditions. A signal cancellation technology has also been proposed for retrieving lower layer signals.
A PHY Layer Emergency Alert System for extra-robust EAS signaling.
Digital Video Broadcasting Project (DVB)
The DVB Project proposes its two most recent terrestrial specifications DVB-T2 and DVB-NGH, which are tightly related to each other. Both systems’ performance is located close to theoretical limits (Shannon). Together they cover fixed, handheld, vehicular and portable reception environments and fulfill all or almost all requirements ATSC listed in its CFP. In particular, DVB-T2 achieved already a worldwide commercial success with its adoption in 56 countries.
The technical cornerstones of our proposed toolbox are the transparency of the physical layer towards the protocol layers above, multiple physical layer pipes of individual robustness, LDPC/BCH error control coding, non-uniform constellations, advanced interleaving, Time Frequency Slicing, Time Division Multiplex including Future Extension Frames, OFDM multi-carrier waveform and MIMO.
DVB likes to underline its support for ATSC’s initiative seeking global alignment of terrestrial broadcasting standards. DVB membership will be open to consider co-working with ATSC to fill any gaps identified between ATSC’s requirements and these proposed specifications to achieve a very high level of alignment between ATSC’s and DVB’s future standards. Furthermore, this proposal provides a joint opportunity to both fora, ATSC and DVB, for a dialogue with 3GPP targeting Common Broadcast Standards.
This submission is a physical layer proposal in response to Call for Proposals for ATSC-3.0 PHYSICAL LAYER, A Terrestrial Broadcast Standard, ATSC Technology Group 3 (ATSC 3.0), March 26, 2013 (“CFP”). This document describes an ATSC 3.0 physical layer, which is full backward compatible with ATSC A/53/153 and based on improved SC-FDMA modulation. The physical layer uses 8VSB, 16VSB line signals, which are produced from multi-carrier signal. The proposed system uses the same data fields and the same synchronization signals as A/53/153 standard. In the ATSC 3.0 mode the physical layer uses frequency domain equalizer and cyclic prefixes for mitigation of reflections.
This proposal addressed to the main characteristics of the physical layer: modulation and demodulation methods, line signals, synchronizations signals, backward compatibility with existing ATSC A/53/153 Standards.
This proposal is not addressed to other functional areas as: Input Formatting, Interleaver, Management and Control signals, error correction, and “other technologies of interest” of CFP.
The functional schematic of proposed ATSC 3.0 transmitter is shown on fig.1. The addressed areas are market by yellow color. The A/53 blocks are not marked. The additional blocks that needs for ATSC 3.0 but not addressed in this proposal are marked by green color.
LG Electronics, Zenith and Harris Broadcast
The FUTURECAST Universal Terrestrial Broadcasting System Physical Layer proposal is the result of a collective effort by LG Electronics, its U.S. R&D subsidiary Zenith, and Harris Broadcast to create the optimum transmission solution for next-generation TV broadcast systems.
Designed to both increase data throughput by 30% and improve multipath performance (compared with the current DTV standard) for fixed and portable TV reception, FUTURECAST also includes energy-saving features for consumer receivers and enhanced indoor TV signal penetration, thanks to flexible coding choices, for mobile reception. Advanced modes also deliver very high data rates or very robust transmission capabilities.
In addition to significantly increased data capacity and improved robustness, key system features include state-of-the-art error correction coding and signal constellations. Optimized pilot patterns promise enhanced performance over traditional OFDM modulation approaches.
Designed for easy extension to various current and future transport formats, FUTURECAST optimizes efficiency for the most-used data formats (Internet Protocol, Transport Stream) via customized stream compression. The system supports single-frequency networks and/or multiple transmitters, and its use of a single RF transmission’s flexible physical layer profile assures optimum quality of service. The extensible new system is designed to support evolution to future broadcast systems even beyond “ATSC 3.0.”
COFDM broadcast systems such as those prescribed by the DVB-T2 standard transmit data twice using rotated 22NQAM constellations with differentially delayed orthogonal coordinates to provide delay diversity. Such systems are espoused because the data conveying capability is the same as for the original 22NQAM constellations before rotation. However, receivers are not simple. The proposal is to use non-rotated 24NQAM constellations with single-time retransmission instead. This maintains data conveying capability and noise performance, but receivers can be simpler. The non-rotated 24NQAM constellations can be non-uniform in regard to spacing between adjoining lattice points, so as to provide better shaping for binary LDPC coding. It is further proposed that the initial and final transmissions of the same 24NQAM constellations be done so as to offset their respective circular DFTs by half a revolution. This allows a receiver to overcome deep frequency-selective fading that spans a large portion, up to one-half, of the RF channel.
National Engineering Research Center of Digital Television (NERC), Shanghai Jiao Tong University (SJTU), Shanghai Advanced Research Institute (SARI) and Bell Labs/Alcatel-Lucent
The radical shift towards mobile screens, wireless rich media and the exponential growing wireless traffics has posed a pressing need for innovative broadcasting services. While the current mega trends of cloud, big data, and mobility actually create an unprecedented opportunity for the broadcasting industry. In this proposal, we address this unique opportunity by presenting an innovative terrestrial broadcasting solution those emphases the following technical and business aspects:
- Ultra high data rate and reliability: the proposed system offers extremely high data rate and reception performance in all wireless environments, and is capable of delivering UHDTV to fixed and portable terminals, robust and scalable programs to portable and mobile users, as well as customized services to dedicated applications and scenarios
- Ultra high network capacity and cost efficiency: In addition to the greatly enhanced link performance, the proposed solution drastically improves the overall network capacity through judicious integration of a suite of sophisticated and yet easily implementable technologies such as the large scale antenna system (LSAS) and intelligent frequency reuse.
- Ultra flexible services: By incorporating advanced technologies such as the cloud transmission, MIMO broadcasting, and broadcasting return channels, the proposal solution provides a highly flexible service platform in anticipation of the rapidly evolving user demands.
NHK, the public broadcaster in Japan, began research in 1995 on 8KSuper Hi-Vision, which delivers an unrivaled sense of presence and enables a viewing experience that is as close to reality as possible. NHK is developing and standardizing new technologies for each stage of the 8K Super Hi-Vision broadcast process, from program production through to transmission and home viewing.
For the next generation of terrestrial broadcasting, NHK is developing large capacity transmission technology using ultra-multilevel OFDM technology (featuring 4096QAM, LDPC, a large FFT size, and more) and dual-polarized MIMO technology (featuring horizontal and vertical polarization at the same frequency).In 2013, NHK demonstrated8K Super Hi-Vision terrestrial transmission in the UHF band at NAB2013.
Key elements of the NHK proposal are:
- Flexible setting of bit-rate from multi HDTV (2K) to 8K Super Hi-Vision.
- Large capacity transmission of over 90Mbps at 6MHz using ultra-multilevel OFDM technology (4096QAM) and dual-polarized MIMO technology.
- Hierarchical transmission using frequency division multiplexing.
- Fixed reception service (UHDTV) and mobile reception service (HDTV) can broadcast simultaneously.
- Large capacity transmission/Robust transmission is selectable at each level.
- Has an IP base interface to ensure high compatibility with other broadband services.
Qualcomm and Ericsson
The world has become a much smaller place; people are more connected and consuming more content across more communication platforms than ever before. Broadcast television is a significant component of this highly connected world. Reaching consumers anywhere anytime requires technology that is easily integrated into both fixed and mobile environments. The Qualcomm and Ericsson proposal addresses the use cases for the ATSC 3.0 physical layer with LTE Broadcast, which is the most appropriate technology platform for addressing both fixed and mobile applications.
Over the last 20 years, the connected world has become Internet dominated. LTE Broadcast’s all-IP approach provides broadcasters the opportunity to leverage the largest possible base of pre-existing applications and developers. With capabilities such as dedicated carrier, carrier aggregation, and Multimedia Broadcast multicast service Single Frequency Network (MBSFN), an LTE Broadcast physical layer can achieve all the requirements of ATSC 3.0. By aligning with and leveraging the standards of 3GPP, ATSC will be able to achieve a ubiquitous service offering. As LTE Broadcast evolves ATSC can evolve with it. With the enhancements described in this proposal, it is possible to cover all use cases envisioned for ATSC 3.0. The capabilities of ATSC 3.0 as described herein enable a relatively clean transition and the potential for expanded services.
Samsung and Sony
Sony and Samsung research teams draw from their well-established experience in TV transmission and reception technologies to bring to ATSC 3.0 this system proposal that strikes a good balance between cutting-edge and easily implementable technology. The proposal adapts DVB-T2 with significant enhancements to address ATSC 3.0 key requirements.
Key proposal attributes:
- High Capacity
- Facilitate deployment of multiple HD programs per RF channel
- Support emerging higher capacity UHDTV services
- Increased Robustness
- Resilience to broadcast propagation impairments improves service area coverage
- Diverse Input Interfaces
- Support IP, TS and yet-to-be defined input stream types
- Configurable parameters enable broadcasters to trade-off capacity versus robustness
- Configure services for fixed and mobile reception on the same RF channel
- Easily deploy both MFNs and SFNs
- Share one RF channel with services targeted at next-generation receivers without affecting existing receivers
- Adopt new input stream types
- Deployment of state-of-art technologies
- Powerful LDPC and BCH coding
- Non-uniform constellations up to 1024-QAM
- PAPR reduction
- Dual-polar MIMO
- Efficient and fast emergency warning system
- Hardware compatibility with second generation broadcast systems such as DVB-T2 will facilitate low-cost realization and fast time to market.
The Technicolor proposal has the following goals:
- Leverage existing standards that are in use today as much as possible
- Lowers receiver development costs
- Provides opportunity for higher volumes to lower receiver hardware costs
- Allows potential for a worldwide standard
- Create a system that promotes cooperation among operators
- More effectively use their available spectrum and bandwidth
- Allows for more creative business opportunities involving multiple broadcasters
- Allows for a simpler service offering from a consumer perspective
- Enhance performance and add missing features
- Add performance enhancements where the cost benefit tradeoff makes sense
- Add features that provide for new business opportunities that fit well with the broadcast environment
- Provide profiles for specific services
- Reduces complexity and allows for more cost effective receiver designs
- Focuses the design tradeoffs to better optimize each service
The baseline for this physical layer proposal is the DVB-T2 standard (ETSI EN 302 755). Some additions have been made to better fit the ATSC requirements and business environment.
- Additional Bandwidth choice to allow dual-channel operation.
- Management information to make it easier for broadcasters to share a single physical channel.
- Non-Uniform Constellations
- Addition of MISO operation from DVB-NGH
- Emergency Alert System capabilities
- Geolocation capabilities
- Reduced Carrier Mode for adjacent channel interference reduction
- Additional Constellation Sizes for professional applications
- Profile definitions for service optimization