Flexible Satellite Direct-to-Home Services With Layered-Division Multiplexing

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 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.

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 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, 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.

Recently advanced time sharing scheme which is characterized as Variable Coding and Modulation (VCM) in satellite broadcasting system was adopted as a countermeasure for heavy rain fading in order to improve link availability in DVB-S2x (Digital Video Broadcasting — Satellite 2nd Generation eXtention) standard. Furthermore, we propose Layer Division Multiplexing (LDM) scheme to satellite broadcasting system for higher spectral efficient transmission and compare it with VCM.

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.

In the present situation, applications related to multimedia are discovered to be comfortable with the use of video. The number of end consumers who use video continues to rise every day. People are presently searching for videos with better quality among the ones that are currently available there. This results in the launch and dissemination of HD (high definition) videos. Ultra high-definition (UHD) videos are becoming more and more popular as a result of this advancement and need. However, as video communication keeps expanding, there is an upsurge in network traffic because of the limited bandwidth, especially among smart cities. Different advancement codecs have been suggested to deal with the data stream to overcome this hazardous circumstance. However, the fact that modern UHD videos have huge amounts of data makes the available codecs even more complicated. UHD videos can be processed with the latest improvement codec, H.265/High-efficiency video coding (HEVC). Nevertheless, it is impacted by increased power consumption and intricate calculations. Limitations in the codec's functionality confine its use to specific applications, preventing its application in wireless, mobile, or portable settings. Hence, this research concentrates on implementing frame-level quality enhancement through a deep learning network known as FQE-Net. The deep learning convolutional neural network (DLCNN) is specifically crafted to manage films with resolutions up to 16K. Its primary objectives include reducing complexity, minimizing artifacts, enhancing the efficiency of the HEVC codec, and compacting energy consumption. To achieve superior efficiency, it is imperative to replace the DWT transforms within the HEVC codec with a DLCNN model. Additionally, incorporating the Content Block Search Algorithm for Motion Estimation and Compensation, alongside filtering techniques like Sample Adaptive Filter and Deblocking Filter, becomes essential. The simulation results showed that the suggested FQE-Net performed better than the conventional techniques.

A broadband spaceborne reflectarray with high polarization purity is proposed for Ultra High Definition TV (UHDTV) broadcasting for direct-to-home (DTH) applications. The provided bandwidth would allow to offer DTH and other services, while the enhanced cross-polarization performance enables the improvement of a better signal-to-interference-plus-noise ratio. The broadband design procedure is based on a multi-resonant unit cell with several degrees of freedom (DoF) and an improved multi-frequency optimization algorithm. It is divided into several stages and sub-stages in order to facilitate convergence towards a broadband, contoured-beam, high-performance design, including the cross-polarization figure-of-merit in the procedure. A one-meter contoured-beam reflectarray working in a 20% frequency band with high polarization purity is presented as an example. The antenna is designed to fulfil the requirements of a European coverage for DTH UHDTV broadcasting in dual-linear polarization. The cross-polarization figure-of-merit greatly improves after the optimization procedure in the whole band, achieving values better than 37 dB in the coverage region, providing an excellent isolation between polarizations. This procedure can also be extended to other satellite applications in dual-circular polarization.

The transoral endoscopic thyroidectomy vestibular approach (TOETVA) is the most recently introduced method of minimally invasive thyroid surgery. To our knowledge, no studies have compared TOETVA outcomes using different laparoscopic systems. This study compared outcomes of TOETVA using conventional high definition (HD) and ultra-high definition (UHD) equipment. Medical data and surgery videos of 62 patients who randomized to undergo thyroid lobectomy by TOETVA using an HD or UHD system from August 2018 to April 2019 were retrospectively reviewed. Endoscopic procedures were divided into four phases: flap creation to isthmectomy (phase I); strap muscle division to upper pole ligation (phase II); trimming recurrent laryngeal nerve (phase III); and ligation of Berry's ligament to complete resection (phase IV). Of the 62 patients, 28 underwent TOETVA using an HD device and 34 using a UHD device. The clinical characteristics of the two groups were not different. Mean operating time for lobectomy was similar in the HD and UHD groups (44.19±9.94 versus 43.47±12.19 min, P=0.825). The times required for phases I (15.02±5.33 versus 13.67±5.44 min, P=0.397); II (12.89±2.84 versus 13.17±5.22 min, P=0.816); III (9.85±4.36 versus 9.98±4.55 min, P=0.918); and IV (6.43±3.69 versus 6.65±3.45 min, P=0.840) were also similar in the HD and UHD groups. The numbers of retrieved lymph nodes did not differ significantly in the HD and UHD groups (3.26±2.62 versus 3.45±2.81, P=0.807). Applying a UHD system in TOETVA resulted in outcomes similar to those observed with a conventional HD system. Operation time tended to be lower, especially for flap dissection, and numbers of harvest lymph nodes tended to be higher in the UHD group. Large-scale studies are needed to assess the advantages of the UHD system.

High capacity IEEE802.11 networks are increasingly supporting data intensive applications. Most of streaming applications are using high quality variable rate traffic which includes HD (High Definition) and UHD (Ultra High Definition) video streaming sources. Such services demand fair QoE for all end users which requires high network QoS as well as inter and intra service fairness. It is a challenging task to offer service fairness in a random access network due to nondeterministic resource allocation techniques. In this paper, we propose two video packet scheduling algorithms for the 802.11 MAC protocol which can offer high QoS as well as fairness among video streams transmitted on the downlink using the IEEE802.11ac MAC protocol. The first algorithm is the FRATXOP that allocates transmission resources for each flow based on experienced network congestion levels to improve throughput of HD and SD video connections. The second algorithm the EAS (Enhanced Access Scheduler) operates in conjunction with the FRA-TXOP to fairly allocate transmission resources to maintain fairness among all video streams. A ns-3 simulation model was developed to evaluate the performance of the above algorithms and compare with the standard IEEE802.11ac MAC protocol. Simulation results show that proposed algorithms can enhance the high network QoS as well as maintain high QoE fairness among all end video users.

With the development of information technology and the ultra high definition(UHD) video industry, the video’s resolution is continuously improving, from the standard definition(SD) era to the high definition(HD) era, and the UHD era. In the field of biomedical engineering, the requirement of medical device endoscope for image resolution is higher and higher. Compared with the traditional HD endoscope system, the UHD endoscope image acquisition system designed in this article uses FPGA(Field Programmable Gate Array) as the processing center. The image resolution is increased from 1920*1080 to 3840*2160. Our system designed a physical layer and protocol layer of MIPI CSI-2 interface that can support 30 frame per second. It proves that our image acquisition system is practical and stable for medical endoscope image acquisition systems and also suitable for ultra-high-definition image systems in other fields.

The migration from High Definition (HD) TV to Ultra High Definition (UHD) is already underway. In addition to an increase of picture spatial resolution, UHD will bring more color and higher contrast by introducing Wide Color Gamut (WCG) and High Dynamic Range (HDR) video. As both Standard Dynamic Range (SDR) and HDR devices will coexist in the ecosystem, the transition from Standard Dynamic Range (SDR) to HDR will require distribution solutions supporting some level of backward compatibility. This paper presents a new HDR content distribution scheme, named SL-HDR1, using a single layer codec design and providing SDR compatibility. The solution is based on a pre-encoding HDR-to-SDR conversion, generating a backward compatible SDR video, with side dynamic metadata. The resulting SDR video is then compressed, distributed and decoded using standard-compliant decoders (e.g. HEVC Main 10 compliant). The decoded SDR video can be directly rendered on SDR displays without adaptation. Dynamic metadata of limited size are generated by the pre-processing and used to reconstruct the HDR signal from the decoded SDR video, using a post-processing that is the functional inverse of the pre-processing. Both HDR quality and artistic intent are preserved. Pre- and post-processing are applied independently per picture, do not involve any inter-pixel dependency, and are codec agnostic. Compression performance, and SDR quality are shown to be solidly improved compared to the non-backward and backward-compatible approaches, respectively using the Perceptual Quantization (PQ) and Hybrid Log Gamma (HLG) Opto-Electronic Transfer Functions (OETF).

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.

The video resolution among broadcasting contents is particularly becoming high toward Ultra High Definition (UHD). Due to its massive size, however, UHD contents cannot be delivered over the existing broadcasting system. To solve this problem, we have considered two aspects: techniques of video codec and transmission. In this paper, we propose service architecture for delivering UHD contents encoded hierarchically over heterogeneous networks. They can be divided into two parts and at the sending entity and then transmitted the part of High Definition (HD) content over the broadcasting network and the rest over the communication network. At the receiving entity, they can be merged into the original contents. The proposed architecture is based on Internet Protocol (IP) in order to be compatible with packet-switched networks.