Layered division multiplexing for satellite broadcasting system

Layered Division Multiplexing (LDM) has demonstrated increased data rate capacity for wireless applications where the service bitrates being multiplexed are unbalanced. Current Direct-To-Home (DTH) broadcasting satellite standards (DVB-S2 and DVB-S2X) include Variable Coding and Modulation (VCM) mode. VCM provides the opportunity to deliver different services on a Time Division Multiplexing (TDM) basis and in consequence target different reception conditions with a single carrier. This article proposes the combination of the tools provided by DVB-S2X with LDM for satellite broadcast and communication systems. This article describes use cases where multiplexing schemes can be beneficial in comparison with VCM (TDM) approach. The use cases include the delivery of High Definition (HD) and Ultra High Definition (UHD) TV services to customers as well as additional communication services. The performance of the proposal is evaluated with simulations under different channels, including the impact of satellite equipment non-linearities. Analysis shows that LDM provides considerable gain in comparison with VCM in both AWGN and non-linear satellite channels.

In ATSC 3.0 physical layer standard, a layered division multiplexing (LDM) scheme has newly accepted as one of the multiplexing schemes in order to improve the reception performance when multiple broadcasting contents are simultaneously delivered through a single RF channel. This paper presents comparison results of LDM and time division multiplexing (TDM) schemes under fixed reception environments, and analyzes the performance gain of LDM over TDM. From the field test results, it was confirmed that the LDM gain in the theoretical analysis is still maintained in the actual field.

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.

In this paper, we present performance evaluation of multiple physical layer pipe (PLP) based layered division multiplexing (LDM) systems for the next generation terrestrial broadcasting. In addition to a conventional multiple-PLP configuration, which is based on time division multiplexing (TDM), a variety of LDM configurations, which includes combinations of TDM and two-layer LDM, and three-layer LDM, are considered. Given three different broadcasting contents are delivered by three PLPs, performance comparison and analysis are provided when four different multiple-PLP configurations including TDM, two-layer LDM, and three-layer LDM are used.

Recent broadcast standards support Layered Division Multiplexing (LDM) to achieve graceful degradation as signal quality degrades at the receiver. LDM is accomplished by using different constellations within the same Radio Frequency (RF) spectrum. LDM thus enables delivering multiple service tiers in a single broadcast channel. LDM when used in conjunction with scalable source coding codecs such as the Scalable extension of High Efficiency Video Coding (SHVC), further helps improve overall spectrum utilization and efficiency. In this paper we investigate a 2-tier broadcast LDM based service with one service tier aimed at lower video resolution such as 540p, 720p, 1080p for a mobile receiver (smaller/indoor antenna) and the other service tier targeting twice the video resolution of the lower tier, for stationary receivers (larger/outdoor antenna). The primary contribution of this paper is to identify 2-tier transmission configurations of interest to broadcasters and compare the spectrum and bitrate coding efficiency gains of an SHVC-based multi-tier service versus a simulcast (single layer) based multi-tier service for an Advanced Television Systems Committee (ATSC) 3.0 transmission system. Bitrate savings ranging from 38% and 57% is observed for the SHVC based layered system. For large coverage and pedestrian with a receiver test scenarios, channel utilization savings ranging from 23% to 46% is observed. For mobile and tablet in bedroom scenarios a smaller broadcast bandwidth savings ranging from 6% to 9% is observed.

<p>Advanced Television Systems Committee (ATSC) 3.0, the new generation digital terrestrial television standard, has been designed for facing the new challenges of the future broadcasting systems. ATSC 3.0 has been built using the most recent cutting-edge technologies. Layered division multiplexing (LDM) is one of the major components of the new system baseline. LDM provides a tool to make flexible use of the spectrum for delivering simultaneous services to stationary and mobile services. This paper presents the performance evaluation of ATSC 3.0 core services in mobile scenarios using LDM. Simulation results are presented to analyze the influence of different LDM ensemble configuration modes for mobile reception. The simulation results have been also confirmed by laboratory tests under different channel models. The signal to noise ratio threshold values confirm the excellent behavior of ATSC 3.0 and LDM in mobile and portable scenarios.</p>

The Advanced Television System Committee (ATSC) is currently developing the next-generation U.S. Digital Terrestrial Television (DTT) standard, known as ATSC 3.0. Two disruptive technologies for the physical layer are being evaluated, Layer Division Multiplexing (LDM) and Time Frequency Slicing (TFS). LDM consist in the transmission of a signal composed of two independent signals (layers) which are superimposed together at different power levels. These two layer can be configured with the desired robustness and capacity. LDM enables the efficient provision of services addressed to mobile and fixed reception in a more efficient way than the classical Frequency Division Multiplexing (FDM) and Time Division Multiplexing (TDM) since full bandwidth and transmission time are used in both layers. However, practical operation is restricted due to several implementation constraints such as the use of common parameters and transmitter blocks for both layers (e.g. a common time interleaver). The use of TFS allows for an improved frequency diversity by the distribution of the service data across multiple Radio Frequency (RF) channels instead of using a single RF channel. The paper investigates the potential gains provided by the increased frequency diversity with TFS in conjunction with LDM.

In this paper, the scheme that combines LDM(Layered Division Multiplexing) to the BST-OFDM(Band Segmented Transmission - OFDM) is proposed for the next-generation DTTB(Digital Terrestrial Television Broadcasting). In the proposed scheme for fixed reception, the parity-check matrix of the conventional LDPC code whose length is 69120 is extended. After that, the extended parity bits are generated by the parity-check matrix and modulated. These modulated symbols are multiplexed by LDM to symbols for mobile reception. The performances of the proposed scheme are evaluated by computer simulations under AWGN(Additive White Gaussian Noise), and the required CNR(Carrier to Noise Ratio) of fixed reception can be improved by the proposed scheme. Furthermore, it is possible to decode received symbols even with existing receivers that don't support LDM demodulation by using the proposed extended LDPC code for fixed reception.

The advent of satellite communications brought a new era to the TV industry. In the early years, however, the use of satellites was quite costly and limited by the modest capacity of the first commercial communications satellites. However, the evolution of satellite technology and the development of satellite aggregators, such as Brightstar, Wold Communications, Bonneville, IDB, Keystone, and Globecast, led to a sharp reduction in the cost of satellite television. The development of full-time, annualized satellite transponder charges – as opposed to per-minute fees – was also critical to the development of much lower satellite television fees. P. Marshall (*) Royal Television Society, London, UK e-mail: pmsatellites@btinternet.com # Springer Science+Business Media New York 2015 J.N. Pelton et al. (eds.), Handbook of Satellite Applications, DOI 10.1007/978-1-4614-6423-5_85-2 1 The evolution of digital television services was another important breakthrough. Instead of the one or two television channels per transponder with analog systems, it became possible to derive up to 18 channels per transponder. Digital transmission speeded up the evolution of domestic television satellite systems and played a key role in the growth of direct-to-home satellite broadcasting. The development of satellite-based video systems was not seamless and encountered periods of major market difficulties. One of the most prominent market development issues was the failure of early direct broadcast satellite systems (or BSS in the terminology of the ITU). However, DBS (or BSS) satellite markets are now well established in international, regional, and domestic markets. They are not only highly successful but represent by far the largest single satellite market in terms of revenues. Most recently, there has been a rapid growth of high-definition television (HDTV) service via satellite. These satellite services compete with coaxial cable and fiber-optic-based CATV systems. The economics of satellite television are quite different from terrestrial networks because once a direct broadcast satellite system is launched and operational there is very little incremental cost beyond the consumer terminal needed to receive service. The advent of new digital interface standards known as digital video broadcast with return channel service (DVB-RCS) and Digital Over Cable Service Interface Standard (DOCSIS) have allowed the rapid development of digital television over satellite and cable systems. DOCSIS is now widely used for both satellite and cable television systems. These digital standards, together with high-power fixed satellite systems and broadcast satellite systems – that by definition have high power – allow not only the distribution of a large number of video channels to consumers but also low-cost distribution of high-speed digital data service to both home consumers and businesses. These digital satellite video systems can be – and indeed are – used to provide broader band digital services to the “edge” of digital networks at low cost. Thus DBS and higher powered FSS satellite systems are now being used to provide commercial broadband data services to business as well as broader band digital services to remotely located consumers.

Layered Division Multiplexing (LDM) is a Non-Orthogonal Multiple Access (NOMA) scheme initially proposed for application in digital terrestrial television standards (ATSC 3.0) providing increased system performance, robustness, throughput and flexibility. Lately, its use on satellite communications has been studied. Results confirm throughput gains with respect to Time Division Multiplexing if services being multiplexed have unbalanced data rates and reception thresholds. This paper targets a deeper insight on the impact of the injection level on the LDM system performance. The paper proposes a system evaluation prototype and a carefully designed simulation methodology. The results show gains ranging from 10% to 65% depending on the injection level applied.

This paper presents Layered Division Multiplexing (LDM), a technology that may be used to provide a flexible multi-layer system transmission by means of spectrum overlay. This technology can be used to simultaneously deliver multiple program streams with different characteristics and robustness for different services (mobile TV, HDTV and UHDTV) in one RF channel. — In Layer Division Multiplex (LDM) the signal to be transmitted consists of a number of different independent signals superimposed together at different injection levels to form a multi-layer signal. Each layer can have its own characteristics. The top layer is the most robust one, which has a negative Signal to Noise Ratio (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 High Definition Television (HDTV) and Ultra High Definition Television (UHDTV). For example, DVB-T2, or an alternative design of a high data rate transmission system can be used for the second layer. The upper layer signal can be a separate program, or be used for delivering supplementary bit rate to be combined with the lower layer signal to provide additional features or achieve higher quality of service (e.g., scalable video coding and placing audio on upper layer for extra robustness).

The next-generation U.S. digital terrestrial television (DTT) standard ATSC 3.0 is the most flexible DTT standard ever developed, outperforming the state-of-the-art digital video broadcasting-terrestrial 2nd generation (DVB-T2) standard. This higher flexibility allows broadcasters to select the configuration that better suits the coverage and capacity requirements per service. Regarding the selection of pilot patterns, whereas DVB-T2 provides eight different patterns with a unique pilot amplitude, ATSC 3.0 expands up to 16, with five different amplitudes per pattern. This paper focuses on the pilot pattern and amplitude performance and optimization for time and power multiplexing modes, time division multiplexing and layered division multiplexing (LDM), respectively, of ATSC 3.0. The selection of the optimum pilot configuration is not straightforward. On the one hand, the pilots must be sufficiently dense to follow channel fluctuations. On the other hand, as long as pilot density is increased, more data overhead is introduced. Moreover, this selection is particularly essential in LDM mode, because the LDM implementation in ATSC 3.0 requires that both layers share all the waveform parameters, including pilot pattern configuration. In addition, there is an error proportional to the channel estimate of the top layer that affects to the lower layer performance.

The most recent standard for broadcast services, Advanced Television System Committee—Third Generation (ATSC 3.0), has adopted co-located multi-antenna schemes and Layered Division Multiplexing (LDM) in order to increase the capacity and reliability compared to former Digital Terrestrial Television (DTT) systems. ATSC 3.0 has adopted both technologies separately, but no combination of them is planned yet. Compared to baseline LDM case, use of several antennas allows for diverse parametrization for each layer. This paper analyzes the potential combination of co-located Multiple-Input–Multiple-Output (MIMO) schemes with LDM. A trade-off analysis between complexity constraints and performance benefits is evaluated.

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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.