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Future 5G systems will include a point-to-multipoint (P2MP) transmission mode to achieve high capacity and high spectrum efficiency for multiple use cases, such as IoT, lifeline communications, and broadcast-type services. Layered-division-multiplexing (LDM) is a novel non-orthogonal multiplexing technology recently adopted by the next generation digital TV broadcast system, ATSC 3.0, which is capable of providing significant capacity improvement when delivering multiple broadcast services simultaneously. This article explores the application of LDM as an enabling technology for 5G to achieve high-efficiency P2MP transmission and to deliver more diversified broadcast-type services using the mobile broadband infrastructure. The potential advantages that can be offered by LDM are demonstrated by capacity analysis and computer simulations. Coverage studies show that a 5G P2MP subsystem with LDM can deliver high-quality broadcast services using the broadband infrastructure. Finally, some general guidelines on the receiver implementation are presented to minimize the hardware complexity of consumer devices. [ABSTRACT FROM AUTHOR]

I wish to extend my deep appreciation to all those who have so generously volunteered their time and talents during 2017 to the peer review and publication of the IEEE Transactions on Broadcasting. Special thanks go to our BTS Publications Chair and Associate Editors who have shared their valuable time and broadcast engineering expertise in managing a steadily increasing flow of papers and evaluating manuscripts through the peer review process. [ABSTRACT FROM PUBLISHER]

Layered division multiplexing (LDM) is a spectrum efficient non-orthogonal multiplexing technology that has been adopted in the Advanced Television Systems Committee (ATSC) 3.0 Physical Layer Standard as a baseline technology. This paper studies a two-layer LDM with one layer used for providing a global service through a single frequency network (SFN), and the other for providing local coverage/services, such as location targeted advertising or local content insertion. The pilot boosting effect on SNR and co-channel interference is also analyzed. The LDM upper layer can be used to deliver time-division multiplexed mobile-HD and 4k-UHD services. The LDM lower layer with a negative SNR threshold can reliably provide seamless local coverage/service from each SFN transmitter without coverage gaps among adjacent SFN transmitter service areas. No directional receiving antenna is required for the local service reception and receivers simply tune into the stronger signal. In such LDM systems, while the upper layer is operating in a traditional SFN mode, the lower layer operates in a special form of distributed MIMO or gap-filler mode to provide targeted local coverage. For implementing the two-layer system introduced in this paper, only ATSC 3.0 baseline technologies are used, i.e., there is no need to modify the ATSC 3.0 standard. Given the upper and lower layers’ data rate requirements and the SNR thresholds, the lower layer power, with respect to the upper layer (injection level), can be optimized to maximize upper and lower layer performance and coverage. Since the advertisement time of the local service is typically less than 20% of the program time, nonreal time could be used to play-back the local content at five times the transmission bit rate for better (audio/video) service quality. [ABSTRACT FROM AUTHOR]

The evolved multimedia broadcast multicast service ( e MBMS) system was developed to achieve higher spectrum efficiency on video traffic delivery over the long term evolution (LTE) networks. As an integrated component of the LTE, e MBMS can be deployed with great flexibility using the existing LTE infrastructure. However, the current e MBMS was designed as a supplementary subsystem, and has limited capability to deliver high-quality broadcast-type video services in a spectrum efficient manner. This paper first studies the capability and limitations of the current LTE e MBMS system to deliver broadcast services when deployed as single-frequency-network (SFN). Next, potential physical-layer enhancements are investigated for future e MBMS systems to achieve enhanced broadcast service delivery capability, higher spectrum efficiency, improved service quality, and more efficient SFN deployment options. These include wideband transmission, non-orthogonal multiplexing, e.g., layered-division-multiplexing technology, and more flexible orthogonal frequency division multiplexing system configurations, such as longer cyclic prefix and smaller subcarrier spacing. Other technologies defined in the latest next generation digital television system are also discussed that might be applicable to the development of a more capable standalone future e MBMS system. [ABSTRACT FROM AUTHOR]

I wish to extend my deep appreciation to all those who have so generously volunteered their time and talents during 2016 to the peer review and publication of the IEEE Transactions on Broadcasting. Special thanks go to our BTS Publications Chair and Associate Editors who have shared their valuable time and broadcast engineering expertise in managing a steadily increasing flow of papers and evaluating manuscripts through the peer review process. [ABSTRACT FROM PUBLISHER]

In this paper, we propose a two dimensional (2-D) code based on a vertical low-density parity check (LDPC) code and a horizontal Reed–Solomon code for the cloud transmission system. The proposed 2-D code shows superior performance under fading channels due to its inherent block-type interleaving feature. Furthermore, the proposed 2-D code can be adaptively decoded to reduce decoding latency and complexity because the vertical LDPC code has raptor-like rate-compatible feature. [ABSTRACT FROM PUBLISHER]

This paper presents the results of the tests performed by the Communications Research Centre Canada (CRC) to determine the levels of electromagnetic radiation resulting from the operation of commercially available in-house power line telecommunication (PLT) devices, and to evaluate their potential effects on FM radio and low-VHF TV broadcasting services. The tests were performed when the devices were operating under real conditions in a number of typical Canadian suburban residential houses. The corresponding field strength measurements were made at specific distances from the houses and could then be compared with the present regulatory limits. [ABSTRACT FROM PUBLISHER]

The intercarrier interference (ICI) matrix for the orthogonal frequency division multiplexing (OFDM) systems usually has a fairly large dimension. The traditional least-square solution based on the pseudo-inverse operation, therefore, has its limitation. In addition, the provision of a sufficiently long training sequence to estimate the complete ICI matrix is not feasible, since it will result in severe throughput reduction. In this paper, we derive a lower hound for the mean-square estimation error among the least-square ICI matrix estimators using different training sequences and prove that the minimum mean-square error (MMSE) optimality is attained when the training sequences in different OFDM blocks are orthogonal to each other, regardless of the sequence length. We also prove that the asymptotical mean-square estimation error using the maximal-length shift-register sequences (m-sequences) as in the existing communication standards is 3 dB larger than that using the perfectly orthogonal sequences for ICI matrix estimation. Thus, we propose to employ the training sequences based on the Hadamard matrix to achieve a highly efficient and optimal IC! matrix estimator with minimum mean-square estimation error among all least-square ICI matrix estimators. Meanwhile, our new scheme involves only square computational complexity, while other existing least-square methods require the complexity proportional to the cube of the ICI matrix size. Analytical and experimental comparisons between our new scheme using Hadamard sequences and the existing method using m-sequences (pseudo-random sequences) show the significant advantages of our new ICI matrix estimator. The proposed method is most suitable for OFDM systems with large amount of subcartiers, using high order of subcarrier modulation, and designed for high-end of RF frequency band, where accurate ICI estimation is crucial. [ABSTRACT FROM AUTHOR]

Transmitter Identification (TxID, or transmitter fingerprinting) technique is used to detect, diagnose and classify the operating status of radio transmitters. Due to an ever- increasing number of transmitters, the need for transmitter identification is becoming an urgent issue, since it enables the broadcast authorities and operators to identify the source of interference. As a result, transmitter identification has been recognized as an important feature in the ATSC Synchronization Standard for Distributed Transmission. A new robust data transmission technique using the transmitter identification (TxID) sequences in the digital TV (DTV) signals is proposed in this paper. The major advantage of this low data transmission system is its robustness and extremely large coverage. The principle of the proposed data transmission system is presented. The modulation technique and throughput of the data transmission system is also evaluated. [ABSTRACT FROM AUTHOR]

A transmitter identification system for DTV distributed transmission network using embedded pseudo random sequences is investigated. Different orthogonal pseudo random sequences and their suitability for transmitter identification are discussed. Code generators are developed to study the auto-correlation and cross correlation properties of the Kasaini sequences. To speed up the identification process, the embedded pseudo random sequence is preferred to be time-synchronized with the DTV frame structure. Therefore, the length of the identification code has to be truncated before it is fitted into each field of the ATSC DTV signal. The impact of truncation noise and in-band DTV interference on transmitter identification is also investigated. It is shown that the auto-correlation and cross-correlation properties are only slightly affected by truncation. It is also found that the dominant interference to the transmitter identification is the in-band DTV signal. The signal to truncation noise ratio and signal to DTV interference, ratio in the correlation output are derived, and verified via simulation. It is further recognized that in-band DiV interference can only be mitigated by increasing the code length or by time-domain averaging technique to smoothen out the in-band interference. [ABSTRACT FROM AUTHOR]

The transition plan from the analog (NTSC) to digital terrestrial television (DTTV) in the USA was based on a simplified version of the Longley-Rice service prediction algorithm, and a link budget that mimicked the traditional planning factors for NTSC. It is now clear that the service prediction and the link budget both have serious shortfalls. This paper provides the formalism required for the development of realistic link budget and service grades for fixed and portable DTTV reception. [ABSTRACT FROM AUTHOR]

Non-uniform constellations (NUCs) successfully utilize geometrical shaping to approach the Shannon capacity, but increase demapping complexity. In this paper, enhanced non-uniform constellations for low-complexity and high-capacity communications are investigated and addressed in two steps: low-complexity demappers for fixed constellations and the constrained design of enhanced NUCs. First, simplified demappers for NUCs are studied, and modified virtual point searching (VPS)-based demappers are proposed. Theoretical analysis and numerical results show that the proposed modified VPS-based demappers reduce demapping complexity with negligible performance degradation. Secondly, two shaping constraint schemes are proposed to NUC design for the purpose of low complexity and high capacity. NUCs optimized under the proposed constraints outperform the uniform constellations, and the proposed demappers have good applicability to the optimized NUCs. The proposed NUC design constraint schemes and simplified demappers enable solutions to achieve low-complexity high-capacity communication. [ABSTRACT FROM AUTHOR]

States that Fast Fourier Transform (FFT)-based Coded Orthogonal Frequency Division Multiplexing (COFDM) is a technique for digital television (DTV) broadcasting over multipath fading channels. Investigation of the in- and out-band behavior of a 64QAM-OFDM system under various nonlinear devices; How hardware nonlinearity affects system performance; Details on signal clipping.

States that Orthogonal Frequency Division Multiplexing (OFDM) is a transmission technique used for Digital Television (DTV) terrestrial broadcasting. Presentation of an application of a filtered decision feedback channel estimator for OFDM-based DTV systems; Details on computer simulations conducted; Indication of channel estimation loss.

Digital Terrestrial Television (DTV) has been widely deployed globally for more than a decade. The transmitter identification (Tx-ID) technique specified in modern DTV standards becomes important today as the number of DTV transmitters grows with the expanded coverage area. In the ATSC standards, Kasami sequences, a crucial class of pseudo random sequences, are considered as feasible Tx-ID sequences because they possess several favorable properties leading to nearly Dirac-delta autocorrelation/cross-correlation functions and large sequence capacities. It is well known that the interference-pluse-noise level (INL) or signal-to-interferenec-plus-noise ratio (SINR) plays a very important role in the Tx-ID system performance. Nontheless, such a crucial factor has been evaluated only in the statistical average due to the difficulty of characterizing the exact pertinent probabilitistic analysis. In this work, we combat the aforementioned difficulty by applying a probability-density approximation method to statistically characterize random variables like INL and SINR. With the exact probability density functions of INL and SINR, we can analyze the detailed statistical characteristics of numerous Tx-ID related parameters, including Tx-ID capacity and reception quality in terms of SINR. Extensive numerical experiments are also undertaken to justify the effectiveness of our proposed new analysis and explore detailed quantitative insight for critical Tx-ID system parameters and performance metrics. [ABSTRACT FROM AUTHOR]

This paper describes systems, devices, and methods to implement a bi-directional integrated inter-tower wireless communications network (IITWCN). The described technology can be implemented in combination with the Broadcast Core Network (BCN) in next generation broadcast eco-system and, therefore, support new business cases for broadcast operators such as the delivery of flexible datacasting services or support broadcast or point-to-point Internet services. The introduced bi-directional inter-tower communications network (ITCN) extends the previous unidirectional in-band distribution links (IDL) and adopts the on-channel repeater (OCR) as a simplified backhaul solution in single frequency networks (SFN). The concept of the coordinated ITCN is also presented, aiming at future broadcast Internet services. The ITCN provides a scalable and configurable network solution embedded in a broadcast system, which becomes independent from any non-broadcasting telecommunication infrastructure. The described technology partially relies on the infrastructure of the underlying broadcast/multicast network, using the allocated service channels without requiring additional frequency bands or a separate frequency band. The bi-directional inter-transmitter communication links are therefore referred to as integrated transmission links and the corresponding network as an integrated network. [ABSTRACT FROM AUTHOR]

This article investigates the non-uniform constellation (NUC) optimization adapted for Hierarchical modulation (HM) without using Successive Interference Cancellation (SIC). This approach is promising to reduce system demod/decode delay in comparison to Layered Division Multiplexing (LDM). By maximizing the constellation constrained capacity of Enhanced Layer (EL) service in HM, while the capacity of Core Layer (CL) service are approximately the same in HM and LDM, the capacity achieved by HM using NUCs is comparable to LDM. Particle Swarm Optimization (PSO) algorithm is used to resolve this problem. To accelerate the optimization, initial constellation is selected from regular NUCs or the combination of CL and EL constellations of LDM in ATSC 3.0. The results imply that under certain capacity demands, especially when there is a large difference between the SNR thresholds of CL and EL or the power ratio of CL to EL is high (for example, 10 dB or higher), HM, with lower delay compared to LDM, can achieve the capacity comparable or even better than LDM with the help of NUCs. Even if the power ratio of CL to EL is relatively low (for example, 3 dB), the capacity loss can be reduced with properly designed NUCs and the SNR threshold loss of EL can be approximately 0.4 dB with respect to LDM. However, LDM is still superior to HM when the difference between the SNR thresholds of CL and EL is relatively low. [ABSTRACT FROM AUTHOR]

To meet the ever increasing demand for better service quality and availability, the next generation digital TV (DTV) broadcast, a.k.a., the ATSC 3.0, is developed with new capabilities to deliver 4K ultra-high-definition (4K-UHD) services to fixed receivers, robust HD-quality services to mobile receivers, as well as non-broadcast services (e.g., broadband), including Internet of Things (IoT), Connected Vehicles, etc. To realize these capabilities, it becomes necessary to evolve the existing single-transmitter high-power-high-tower (HPHT) network to multi-transmitter low-power-low-tower single-frequency-networks (SFN), which requires installing new transmitters. Each new transmitter needs a feederlink to receive the service data from the broadcast gateway (BG) for transmission. This feederlink contributes to a significant portion of installation and operational costs of the new transmitters. This paper proposes a wireless in-band distribution link (WIDL) technology, where the distribution data is delivered to the newly deployed transmitters from the existing DTV towers wirelessly sharing the same TV band with the broadcast services. The distribution signal is multiplexed with service signal in the same ATSC 3.0 waveform. Layered division multiplexing (LDM) technology is proposed to achieve more efficient transmission of the distribution signal. The WIDL offers better performance and more robust operation than the on-channel repeater (OCR) technologies. More importantly, it offers the possibility of delivering backhaul data for future applications over the DTV infrastructure, such as IoT and connected vehicles. Therefore, the proposed WIDL is one enabling technology to achieve convergence of broadcast services with broadband and other wireless services on the DTV spectrum. [ABSTRACT FROM AUTHOR]

Non-uniform constellation (NUC) is an advanced technology in digital terrestrial television broadcasting (DTTB) systems to reduce the shapping gap of BICM capacity to Shannon theoretical limit and provide performance gain. Two-dimensional NUC (2D-NUC) is a kind of NUC providing more gain but bringing higher demapping complexity at the receiver, which hinders its application prospects, especially in power limited systems. This paper proposes three novel demapping algorithms with reduced complexity for low to medium code rate 2D-NUCs in Advanced Television Systems Committee 3rd Generation (ATSC 3.0) standard. The proposed algorithms are based on the introduction of virtual points, the strategy of condensed symbols reduction and some reasonable approximations. There is a trade-off between the demapping complexity and performance. These three algorithms have different degrees of reduction in complexity and performance degradation, so they accommodate for different practical requirements. Theoretical analysis and simulation results are also given in this paper to prove the efficiency of the proposed demapping algorithms with reduced complexity. [ABSTRACT FROM AUTHOR]

I wish to extend my deep appreciation to all those who have so generously volunteered their time and talents during 2015 to the peer review and publication of the IEEE Transactions on Broadcasting. Special thanks go to our BTS Publications Chair and Associate Editors who have shared their valuable time and broadcast engineering expertise in managing a steadily increasing flow of papers and evaluating manuscripts through the peer review process. [ABSTRACT FROM PUBLISHER]

I wish to extend my deep appreciation to all those who have so generously volunteered their time and talents during 2014 to the peer review and publish IEEE Transactions on Broadcasting. Special thanks to our BTS Publications Chair and Associate Editors who have shared their valuable time and broadcast engineering expertise in managing a steadily increasing flow of papers and evaluating manuscripts through the peer review process. [ABSTRACT FROM AUTHOR]

The development of 5G system provides a unique opportunity to implement a unified wireless transmission platform that can simultaneous deliver unicast, multicast and broadcast services using the same spectrum and the same infrastructure. This can be achieved by developing a more capable point-to-multipoint transmission (PTM) system component, also called 5G Multimedia Broadcast Multicast Services (5G-MBMS). A properly designed 5G-MBMS could achieve the convergence of terrestrial mobile broadband and TV broadcasting systems.By inherently allowing dynamic spectrum allocation among different types of services, this converged system could offer significant higher spectrum utilization. In this paper, the power-based non-orthogonal multiplexing (P-NOM) technology is proposed in addition to the existing orthogonal time-division-multiplexing (TDM) scheme. Significant capacity gains could be achieved by using P-NOM in a 5G-MBMS system for delivering different types of broadcast services, and for delivering mixed unicast and broadcast services. The capacity benefits of a 5G-MBMS with P-NOM is demonstrated by both theoretical analysis and computer simulations. A key finding is that using a two-layer P-NOM can essentially deliver a broadcast service on top of a unicast network, each achieving nearly full capacity. Next, a complexity analysis will reveal that implementing P-NOM in a 5G-MBMS system does not require significant additional complexity at consumer devices. Finally, it will be shown that, different from the non-orthogonal-multiple-access (NOMA) technologies, using P-NOM in 5G-MBMS system requires little or no change to the existing radio resource allocation mechanisms in LTE and 5G, when one power layer is used for broadcast services delivery. [ABSTRACT FROM AUTHOR]

This article presents the periodical's deep appreciation to all those who have so generously volunteered their time and talents during 2004 to the peer review and publication of "IEE Transactions on Broadcasting." Special thanks go to BTS Publications Chair and Associate Editors who have shared their valuable time and broadcast engineering expertise in managing a steadily increasing flow pf papers, and evaluating manuscripts through the peer review. These reviewers are critical to the peer review process and ensure that the periodical publishes high quality and timely papers.

The goals of ATSC 3.0 are to improve the television viewing experience with higher audio and video quality, compression efficiency, robust transmission for reception on both fixed and mobile devices, and more accessibility, personalization, and interactivity. ATSC is also addressing changing consumer behavior and preferences, providing TV content on a wide variety of devices. Furthermore, ATSC is working to add value to the broadcasting service platform, extending its reach and adding new business models—all without the restriction of backward compatibility with the legacy system. Formal planning for ATSC 3.0 began back in 2010 in a planning team tasked with looking at what a next-generation system might look like. Requirements were subsequently developed based on the usage scenarios. Formal standards development work began in 2012, with the first specification completed and published in March 2016. ATSC 3.0 is being built to last. Technology advances rapidly and so methods to gracefully evolve have been built into the core of the system. An essential capability is to signal when a layer or components of a layer evolve—including the ability to signal minor version changes and updates, and major version changes and updates. The goal of this flexibility is to avoid disruptive technology transitions, and to enable graceful transitions from one technology to another. [ABSTRACT FROM AUTHOR]

In conventional differential detection (CDD), the previous received symbol is used as the phase reference for the current received symbol, therefore the channel variation due to fast fading causes an error floor. We propose a novel iterative decision-directed differential detection (iD4) algorithm for orthogonal frequency division multiplexing (OFDM) systems employing differential PSK modulation in each subcarrier. The core of iD4 is a low complexity time and frequency 2-D estimator which can effectively estimate the channel variation experienced by adjacent time domain symbols. This estimated channel variation is then compensated in the differential detection process. Both theoretical analysis and computer simulations show that significant performance improvement can be achieved using iD4 over the CDD for OFDM receivers in fast fading channels. [ABSTRACT FROM PUBLISHER]

Layered-division-multiplexing (LDM) technology is a non-orthogonal multiplexing technology to provide more efficient transmission of multiple services that have different requirements on the robustness and throughput in one TV channel. The core of LDM is to transmit multiple-layer signals, where each layer occupies the whole channel bandwidth and the whole time. To meet the different requirements on different layers, each layer is allocated a specific power level, and is configured to use a different channel coding and modulation scheme, as well as its own multiple-antenna technology. Delivering robust and high-quality mobile TV services is one of the top priorities for the next generation digital TV (NG-DTV) systems. In this paper, we first investigate the performance of the NG-DTV systems with LDM in various difficult propagation channels that are likely encountered by the large variety of mobile devices, including fast-fading channels, slow-fading channels, indoor channels, and single-frequency-network (SFN) channels. A new channel estimation technique is proposed to overcome the severe performance degradation caused by the SFN channels. We will further show that using LDM makes it possible to deliver mobile services using the efficient 32k transmission mode. Finally, receive antenna diversity is shown to provide different levels of performance improvement for different LDM configurations. [ABSTRACT FROM PUBLISHER]

In-band full duplex (IBFD) communications are a potential solution to spectrum scarcity. IBFD communications offer greater spectral efficiency than traditional half-duplex communications by transmitting and receiving on the same frequency channel. However, IBFD operation requires overcoming the challenge of eliminating the self-interference coupled from the transmit antenna to the receive subsystem. Knowledge of the characteristics of the loopback propagation channel makes it easier to cancel out the self-interference. Nevertheless, complex field trials are required to adequately characterize loopback channels, which is still lacking in the recent literature. This paper proposes a measurement campaign in a real and ongoing broadcast transmission center to characterize the main characteristics of loopback channels. The work proposes a set of loopback channels based on field trials and an empirical analysis of the most relevant parameters of the channel model, such as the Doppler spectrum, the delay spread, and the K-factor. • A new methodology for measuring and characterizing broadcast loopback channels. • Characterizing the loopback channel in terms of the amplitude and the delay of the paths. • An analysis of the obtained delay spread and K-factor values. • Characterizing the Doppler spectrum of the loopback channel in broadcast transmitters. • Performance evaluation of the proposed channel models under an ATSC 3.0 compliant transceiver chain. [ABSTRACT FROM AUTHOR]

The media landscape is undergoing unprecedented transformations. Content creators and service providers had been for decades in control of how technology tailored to media applications was deployed and adopted in networks and devices to serve audiences. Disruption started when the Internet and global technologies and networks enabled content delivery and consumption at anytime, anywhere, and by means of any device. This new paradigm, where the Internet is fully accessible to the media industry, creates opportunities for innovation across the entire value chain, involving new services, innovative products, and a direct relationship with users. [ABSTRACT FROM AUTHOR]

The transmitter identification (Tx-ID) technique has been widely addressed in the modern advanced television systems committee digital television (DTV) standards. Kasami sequences are adopted as the Tx-ID sequences due to the favorable code capacity. However, the conventional cross-correlation based Tx-ID technique cannot combat the realistic multipath channel impairment. Therefore, in this paper, we propose a new least-square Tx-ID approach, which is demonstrated to be very robust when the multipath channels are encountered. We also establish the new Hessian analysis to provide the range for appropriate injection levels accordingly. Based on this new theoretical study, we design new efficient (fast) algorithms to determine the maximum allowable channel length given a particular Kasami Tx-ID sequence. These algorithms and theoretical results can be very useful for the future DTV technologies. [ABSTRACT FROM AUTHOR]

In this paper, we explain an additional data transmission (ADT) increasing the data capacity of the advanced television systems committee terrestrial digital television (DTV) system, present its field test results conducted in Jeju Island, Korea, and analyze the results in different scenarios. The ADT system can offer an additional data of rate from a few hundred bits per second (bps) to a few megabits per second based on a transmitter identification (TxID) or successive interference cancellation (SIC) techniques. For the field test, the field strength and the required carrier to noise ratio for a stable reception were measured at each test point. Based on the field test, we verify that the TxID- and SIC-based ADT systems can provide an additional data link supporting 160 bps data rate, which is at least 13 dB robust compared to the conventional DTV system, and 2 Mbps data rate which is about 3 dB worse than the conventional DTV system, respectively. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Highlights: [•] Acupuncture at HT7 inhibited the ethanol withdrawal-induced decrease of NPY protein level in the CeA. [•] Acupuncture at HT7 reversed the ethanol withdrawal-induced reduction of NPY mRNA level in the CeA. [•] Acupuncture at HT7 normalized the ethanol withdrawal-induced reduced ratio of p-CREB/CREB in the CeA. [•] The anxiolytic effect of acupuncture was blocked by the intra-CeA infusion of BIBP 3226. [•] The anxiolytic effect of acupuncture was not blocked by the intra-CeA infusion of BIIE 0246. [ABSTRACT FROM AUTHOR]

In this brief, we propose a newly designed quarter-rate quasi-cyclic low density parity check (LDPC) code for the cloud transmission system. The cloud transmission system requires a near Shannon limit low-rate coding for the next generation terrestrial digital television system. The proposed LDPC code is optimized for R=\scriptstyle1/\scriptstyle4. At the code length of 64 K, it is only 0.6 dB away from Shannon limit. [ABSTRACT FROM PUBLISHER]

In this paper, we propose a novel augmented data transmission (ADT) system based on low density parity check (LDPC) code for an additional data stream transmission in the Advanced Television Systems Committee (ATSC) terrestrial digital television system. The LDPC code-based ADT system can provide additional data of rate up to 3 megabits per second (Mbps), which is significantly improved over the conventional data transmission schemes used in the transmitter identification system. Based on the laboratory test, we verify that the LDPC code-based ADT system is only about 1.1 dB away from Shannon limit. [ABSTRACT FROM AUTHOR]

The transmitter identification of the DTV systems becomes crucial nowadays. Transmitter identification (TxID, or transmitter fingerprinting) technique is used to detect, diagnose and classify the operating status of any radio transmitter of interest. A pseudo random sequence was proposed to be embedded into the DTV signal before transmission. Thus, the transmitter identification can be realized by invoking the cross-correlation functions between the received signal and the possible candidates of the pseudo random sequences. Gold sequences and Kasami sequences are two excellent candidates for the transmitter ID sequences as they provide a large family of nearly-orthogonal codes. In order to investigate the sensitivity of the transmitter identification to different topologies and different Kasami sequence lengths, we present the analysis here for four different geometric layouts, namely circular distribution, doubly concentric and circular distribution, square array and hexagonal tessellation under the ENG (electronic news gathering) crews? working environment. The coverage area and the lowest received signal-to-interference ratio are considered as two essential parameters for the multiple-transmitter identification. It turns out to be that the larger the Kasami sequence length, the larger the received signal- tointerference ratio. Our new analysis can be used to determine the required Kasami sequence length for a specific broadcasting coverage [ABSTRACT FROM AUTHOR]

The popularity of Advanced Television System Committee (ATSC) mobile digital television (DTV) [mobile/handheld (M/H)] cultivates a fast growing demand on transmitter identification (TxID) in a mobile environment. The ATSC A/110 standard addresses this need with a TxID system using a radio-frequency (RF) watermark. This paper studies the use of DTV signal cancellation techniques in RF watermark detection. In particular, we develop two schemes, namely, decision feedback convolution and decision feedback equalizer (DFE) decision-directed (DD) error, to meet different application scenarios. The first scheme is designed for static and slow-fading channels, whereas the second scheme is designed for dynamic and fast-fading channels. We have conducted computer simulation on TxID over various channel conditions to evaluate the performance of our schemes. Numerical results show that DTV signal cancellation can significantly boost the signal-to-noise (SNR) level of RF watermark and thus reinforce TxID in a mobile environment. [ABSTRACT FROM PUBLISHER]

The new ways to consume and deliver media content in a wireless environment have led to a significant increase in the demand for spectrum resources. In addition, the arrival of next-generation wireless communication technologies has encouraged the creating of new verticals targeting novel applications, such as industry IoT, e-health, distance learning, smart city, smart-metering. All these new use cases are centred on an IP-based infrastructure. A promising alternative to satisfy the demand for resources is to incorporate a new delivery mechanism that can alleviate the congestion of classical cell-based point-to-point broadband wireless infrastructures. The best-positioned candidate is the next-generation Digital Terrestrial Television system, which offers a very spectrum efficient one-to-many PHY, and for the first time, native IP support. In ATSC 3.0, the whole system was designed with an IP-centric view, whereas DVB has created standards to deliver services to generic IP devices (DVB-I). Nevertheless, there is still a last missing piece to bring the broadcast infrastructure to the IP-connected world: a Broadcast Core Network (BCN). In this paper, the basics of a BCN are presented with new use cases that are attractive to Broadcast Network Operator (BNO). A possible roadmap towards implementation is described, and a service-based architecture for a BCN is presented and discussed. [ABSTRACT FROM AUTHOR]

Asynchronous online discussions (AODs) can fail to benefit student learning in online classes if they are not designed to promote higher-order thinking. AODs can be designed as collaborative learning events that prompt students to go beyond the reproduction of basic content. The purpose of this study was to describe student participation, interaction, and levels of learning in AODs following pre-work activities. The pre-work in this study was conceptualized as socio-cognitive scaffolding. It engaged students in common activities where everyone experienced the same content preparation prior to the AOD. During the AOD students were prompted to share, discuss, and validate their understanding of the content. The study was conducted with 49 students in a graduate-level project management course. Results revealed that students were engaged in discussions of content-related material and showed evidence of deep learning during the AODs. Specifically, students analyzed, evaluated, and synthesized information during the collaboration. Results suggested that pre-work activities can be a promising strategy in the design of AODs. • Collaborative asynchronous online discussions (AOD) in an online graduate course were analyzed using socio-cognitive theory. • Students (n = 49) completed pre-work activities that engaged them in learning basic content before joining collaborative AOD. • Analysis revealed surface learning by reproducing facts; deep learning when applying, analyzing and synthesizing content. • Focused pre-work on content before collaborative AOD is a promising strategy in designing online courses for deep learning. [ABSTRACT FROM AUTHOR]

This paper analyzes reliability and quality gains that can be achieved by a broadcast-unicast convergent platform operating in non-orthogonal multiple access (NOMA)-based cellular networks. The analysis is addressed in network scope, dealing with randomly distributed users and base stations (BSs) within a stochastic geometry framework. Additionally a well-known Zipf-distribution popularity model on user demands is also taken into account, which effectively reflects a broadcasting gain from reducing redundant resource expense toward the users demanding same contents. Based on the stochastic modeling, closed-form delivery success probabilities and the consequent transmission rates are analytically derived, where the derivations are obtained separately for the networks with different access control strategies. Furthermore, the optimal broadcast content selection strategy maximizing the transmission rates is proposed. By means of numerical calculations, NOMA is shown to achieve substantial gain at broadcast/unicast joint transmission compared to the conventional orthogonal multiple access (OMA) network, particularly for the service configuration with popular contents having lower target service rates than less popular contents as long as the number of broadcast programs is restricted to be equal to the number of unicast services in a single frame. [ABSTRACT FROM AUTHOR]

This paper presents performance analysis of the Advanced Television Systems Committee (ATSC) 3.0 physical layer protocol in mobile multipath channels. Given the recommended configurations for ATSC 3.0 mobile services, intensive computer simulations as well as laboratory tests are conducted to verify the performance of various modulation and code combinations in ATSC 3.0 physical layer protocol. The results demonstrate that the ATSC 3.0 physical layer can reliably deliver intended mobile services in high-mobility scenarios. [ABSTRACT FROM AUTHOR]

The Fifth generation of mobile broadband (BB) networks, popularly known as 5G, aims to revolutionize different vertical industries, including media broadcasting. Although it remains to be seen the real impact and timescale of the 5G revolution, 5G may represent an opportunity rather than a threat for broadcast (BC), especially when considering new approaches for BC and BB evolving into new converged platforms inter-connecting terrestrial BC and cellular/wired BB systems together [item 1) in the Appendix]. Hybrid BC-BB platforms are already a success in several countries, based, e.g., on HbbTV in EU, hybridcast in Japan and Ginga in Brazil. But the increasing importance of fixed and mobile BB IP delivery for television services, well-illustrated by the new IP-based ATSC 3.0 standard [item 2) in the Appendix] and the on-going DVB-I (Internet) specification, and the fact that the 5G system will support and be interoperable with non-3GPP access technologies, potentially allowing multiple access technologies to be used simultaneously for one or more services, opens the door to new convergence scenarios. [ABSTRACT FROM AUTHOR]

This paper addresses the challenge of broadcast and unicast convergence by proposing a PHY/MAC (Physical Layer/Medium Access Control) architecture for 5G New Radio (NR). The solution is based on Power domain Non Orthogonal Multiple Access (P-NOMA). The main PHY/MAC configuration parameters have been analyzed theoretically and their impact on the service configurations is presented in this manuscript. The system concept has been translated into a prototype model and different evaluation tests are presented. First, simulations show that the PHY layer performs better than Time Division Multiplexing/Frequency Division Multiplexing (TDM/FDM) choices of current broadband access systems. Second, performance tests using a network simulation tool are described. The results for capacity, latency and reliability demonstrate that the proposed solution offers an excellent broadcast/unicast convergence choice with significant gain values with respect to legacy PHY/MAC alternatives. [ABSTRACT FROM AUTHOR]

Broadcasting and broadband network is moving towards integration and LTE-based 5G terrestrial broadcast is now researched in Release 16 in Third Generation Partnership Project (3GPP) standardization meetings. However, the work scope of LTE-based 5G terrestrial broadcast focuses on specifying new numerologies and some minor improvement on cell acquisition subframe, which is insufficient. In this paper, limitations in coding and modulation schemes of LTE-based 5G terrestrial broadcast system, e.g., Turbo codes and Quadrature Amplitude Modulation (QAM), are detailedly analyzed. To further enhance the spectrum efficiency of LTE-based 5G terrestrial broadcast system, LDPC (Low Density Parity Check) codes from 5G new radio (NR) standard and newly designed non-uniform constellations (NUCs) are adopted in this paper to replace Turbo codes and QAM respectively. Extensive simulations and complexity analysis show that the proposed LDPC coding and NUC modulation scheme, either standalone or combined, can provide significant performance gain over Additive White Gaussian Noise (AWGN) and Tapped Delayline (TDL) channels, without additional complexity. To summarize, this paper investigates the weakness of the coding and modulation schemes in current systems and provides potential alternatives for the enhanced future broadcast in 3GPP standard. [ABSTRACT FROM AUTHOR]

This paper introduces a novel automatic modulation classification (AMC) method using the graph-based fractional lower-order cyclic-spectrum analysis in the $\alpha$ -stable noise environment. The noise in the practical communication scenario usually exhibits impulse characteristics in the statistical sense, which could be modeled as the $\alpha$ -stable distribution. This would make the second- or higher-order statistics of the received signal vanish, and thus the performances of the conventional AMC algorithms designed for Gaussian noise significantly deteriorate when directly employed in the $\alpha$ -stable noise. In our proposed framework, the fractional lower-order cyclic spectrum (FLOCS) analysis is first invoked to acquire the polyspectra of the signal corrupted by the $\alpha$ -stable noise. Then, the graph-based AMC mechanism is systematically established upon the graph representation of the FLOCS to identify the modulation type according to the discrepancies between the graph features derived from the training and test data. The performance of our proposed new algorithm is theoretically analyzed, and the correct classification probability $P_{\text{cc}}$ over the modulation candidate set is formulated analytically. The remarkable scalability and efficiency of our proposed approach for the modulation candidate set variation are also theoretically investigated in detail. Monte Carlo simulation results demonstrate the effectiveness and superiority of the proposed AMC scheme. [ABSTRACT FROM AUTHOR]

Flexible and robust transmission schemes are required to support different coded modulation modes, receiver types and channel conditions in future broadcasting systems. However, conventional low-density parity-check (LDPC) coded schemes are usually optimized towards particular scenario, and may face the problem of performance degradation in other different scenarios. In this paper, a type of quasi-cyclic spatially coupled LDPC (QC-SC-LDPC) codes, which have been recently proven to be able to universally achieve capacity over different channels under conventional belief propagation decoding, are proposed as the forward error correcting codes for broadcasting applications. Then a QC-SC-LDPC coded transmission scheme is proposed, which is capable of showing good performance in various scenarios under practical constraints of finite coupling length, smoothing parameter, uncoupled code length and number of decoding iterations. To maintain the universal property under the above constraints, a typical construction method is developed, based on which a QC-SC-LDPC code is constructed as an example. Finally, the performance and robustness of the proposed QC-SC-LDPC coded transmission scheme are demonstrated via simulations under different yet typical coded modulation modes and channel conditions. [ABSTRACT FROM AUTHOR]

Recently, a new structure of low density parity check (LDPC) code named raptor-like LDPC code has attracted much attention. It has better performance at low code rate. In this paper, a novel decoding scheme for raptor-like LDPC code is proposed. First, the Gaussian approximation density evolution (GADE) algorithm is used to track and analyze the message transmission during the decoding process. It is found that certain log likelihood ratio (LLR) messages can be approximated by “zero” setting in the early iteration of raptor-like LDPC decoding. In other words, some column and row operations could be eliminated without compromise the performance. Next, we propose a new decoding scheme, which can skip unnecessary column and row operations. In comparison with the traditional belief propagation (BP)-based LDPC decoding scheme, the proposed scheme can reduce the decoding complexity. Additionally, a new algorithm is developed to facilitate the selection of the early iteration number. With this novel design, the proposed decoding scheme performs almost the same as the traditional BP-based scheme. To proof the concept, the raptor-like LDPC codes in the ATSC3.0 digital TV system are used to evaluate the proposed scheme, in comparison with the traditional BP-based schemes, i.e., sum-product algorithm (SPA), offset min-sum algorithm (OMSA), and normalized min-sum algorithm (NMSA). The simulation results confirm that the proposed scheme can reduce the decoding complexity without sacrifice in performance for all SPA, OMSA, and NMSA methods. About 10% complexity reduction can be achieved. This will reduce the buttery consumption for Internet of Things (IoT) and handheld devices. [ABSTRACT FROM AUTHOR]

This paper presents the advanced television systems committee (ATSC) 3.0 physical layer system performances with different modulation and channel coding combinations. Numerous computer simulations, laboratory tests, and field trials are conducted under additive white Gaussian noise, RC20, and RL20 channels. Analysis of the results shows that the measured values in laboratory and field are less than 1 dB away from computer simulation results. This confirms that the ATSC 3.0 physical layer is capable of providing services ranging from ultra-robust reception (negative SNR operation with QPSK and 2/15 low density parity check (LDPC) code) to very high-throughput (over 50 Mb/s with 4096-non-uniform constellation and 13/15 LDPC code) in real field environments. [ABSTRACT FROM AUTHOR]

Abstract The present study, we prepared polysaccharides from Rosa rugosa petals (RRPS) using hot-water extraction and purified the polysaccharides by chromatography to obtain RRPS-1 and RRPS-2. Preliminary structural features of RRPS were characterized by different instrumental methods, such as HPGPC, FT-IR, and GC analysis. The average molecular weights of RRPS-1 and RRPS-2 were 8.8 kDa and 443.8 kDa, respectively. Then, antioxidant and moisture-preserving activities of RRPS were determined in vitro. The analysis of antioxidant activities suggested that RRPS-2 had good potential for scavenging activity of radicals. We also found that the RRPS-2 has strong moisture-preserving activity in vitro. These results clearly indicated that RRPS-2 might have a good potential to be utilized in pharmaceutical, food and cosmetics industries. Highlights • Two polysaccharides had been isolated from Rosa rugosa petals. • Preliminary characterization of the two polysaccharides was investigated. • The antioxidant and moisture-preserving activities were studied in vitro. • RRPS-2 suggested significant antioxidant and moisture-preserving activities. [ABSTRACT FROM AUTHOR]

In this paper, we present an efficient transmission method of multiple broadcasting services using layered division multiplexing (LDM) and scalable high efficiency video coding (SHVC) based on the next generation terrestrial digital broadcasting standard, advanced television systems committee 3.0. In a two-layer LDM system, each layer forms a physical layer pipe that carries base layer and enhancement layer video streams of SHVC, respectively. This combination of physical and presentation layers technologies can maximize channel utilization when multiple broadcasting services are delivered in a single radio frequency channel with different robustness and reception conditions. An intensive performance analysis is provided when the proposed combination of LDM and SHVC is compared with other approaches, such as time division multiplexing and/or high efficiency video coding simulcast broadcasting. Several performance measurements are also introduced, such as constant data rate measurement and constant quality measurement, which are used to evaluate the performance of video codecs in conjunction with different physical layer system parameters. A prototype hardware system with LDM and SHVC capable of selecting different parameter combinations is tested in the laboratory and in real field environments to verify the performance and feasibility of the proposed LDM and SHVC combination. Results show that the proposed LDM and SHVC combination provides significant gains on video service quality as well as reception robustness. [ABSTRACT FROM AUTHOR]

With the proliferation and diversification of mobile communication services, the current mobile broadband networks face severe challenges. The progressive video service that will make up the majority of future network traffic has more demands for transmission bandwidth, network capacity, and management flexibility. Moreover, denser connectivity, higher reliability, lower latency, and better interaction impose some great challenges to existing networks. In order to meet these growing demands, a promising approach is to integrate a broadcast network with a cellular network. In this article, we briefly set forth the latest progress on the cellular network and the broadcast network, respectively. Then the logic architecture of the integrated network is given to clarify the functional partitioning. In addition, the physical architecture of the integrated network is presented to enable coordination in different aspects. Some feasible strategies are discussed and several promising technologies are presented. [ABSTRACT FROM AUTHOR]