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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]

In this paper, simple methodologies of deep learning application to conventional multiple-input multiple-output (MIMO) communication systems are presented. The deep learning technologies with deep neural network (DNN) structure, emerging technologies in various engineering areas, have been actively investigated in the field of communication engineering as well. In the physical layer of conventional communication systems, there are practical challenges of application of DNN: calculating complex number in DNN and designing proper DNN structure for a specific communication system model. This paper proposes and verifies simple solutions for the difficulty. First, we apply a basic DNN structure for signal detection of one-tap MIMO channel. Second, convolutional neural network (CNN) and recurrent neural network (RNN) structures are presented for MIMO system with multipath fading channel. Our DNN structure for one-tap MIMO channel can achieve the optimal maximum likelihood detection performance, and furthermore, our CNN and RNN structures for multipath fading channel can detect the transmitted signal properly. [ABSTRACT FROM AUTHOR]

We study channel pre-inversion and vector perturbation (VP) schemes for large-scale broadcast channels, wherein a transmitter has M transmit antennas and is transmitting to K single-antenna non-cooperating receivers. We provide results which predict the capacity of MMSE pre-inversion as \boldsymbol K\rightarrow \infty . We construct a new VP strategy, max-SINR VP (MSVP), which maximizes a sharp estimate of the signal-to-interference-plus-noise ratio. We provide results which predict the performance of MSVP and demonstrate that MSVP outperforms other VP methods. Lastly, we combine MSVP with the low-complexity sorted QR precoding method to show that MSVP has the potential to efficiently deliver data to a very large number of users at close to channel capacity. [ABSTRACT FROM PUBLISHER]

In the ATSC 3.0 PHY layer standard, a transmitter identification (TxID) signal is defined in order to provide the identification of an ATSC 3.0 transmitter. TxID signal can also be used to find the co-channel and adjacent interference signals, to assist accurate location finding calculation, and to obtain the channel estimation for each transmitter, which can help local service (e.g., targeted advertisement) reception, as well as for emergency alert. For efficient use of spectrum and quality of service improvement, single frequency network (SFN) where all transmitters share a single RF channel is often implemented. The recently developed ATSC 3.0 physical layer standard has been designed to support SFN. For efficient designing, fine-tuning and operating an SFN, it is crucial to identify each transmitter, as well as to adjust transmitting power and emission time of each transmitter. This paper presents TxID for ATSC 3.0, and analyzes its detection performance under very low signal to noise ratio environments and other applications, such as location finding, and channel estimation etc. for each SFN transmitter. [ABSTRACT FROM AUTHOR]

The final coverage and associated performance of a single frequency networks (SFNs) is a joint result of the properties of all transmitters in the SFN. Due to the large number of parameters involved in the process, finding the right configuration is quite complex. The purpose of this paper is to find optimal SFN network configurations for second generation digital terrestrial broadcast system (DVB-T2). Offering more options of system parameters than its predecessor DVB-T, DVB-T2 allows large SFN networks. However, self-interference in SFNs gives rise to restrictions on the maximum intertransmitter distance and the network size. In order to make optimum use of the spectrum, the same frequency can be reused over different geographical areas—beyond the reuse distance to avoid co-channel interference. In this paper, a methodology based on theoretical network models is proposed. A number of network architectures and network reference models are considered here for different reception modes in order to study the effects of key planning factors on the maximum SFN size and minimum reuse distance. The results show that maximum bitrate, network size, and reuse distance are closely related. In addition, it has been found that the guard interval is not the only limiting parameter and that its impact strongly depends on the rest of DVB-T2 mode parameters as well as on the network characteristics (equivalent radiated power, effective height, and intertransmitter distance). Assuming that the carrier to noise ratio requirements are in the vicinity of 20 dB and bitrates over 30 Mb/s, it has been found that the network can be as large as 360 \times 360 km (delivering 39.2 Mb/s) or even 720 \times 720 km (delivering 37.5 Mb/s). The reuse distance will also have a complex dependency on the DVB-T2 mode and especially the network parameters, ranging from below 100 to 300 km. [ABSTRACT FROM PUBLISHER]

The discussion around different network architectures, namely high power/high tower (HPHT) versus low power/low tower (LTLP) is currently a hot topic in different international fora. This paper presents the results of a study to compare coverage, number of sites, and network deployment/maintenance costs associated to three different network configurations (HPHT only, LTLP only, and mixed HPHT + LTLP) for rooftop, mobile, and portable indoor/outdoor digital terrestrial television service delivery. The analysis has been based on a practical network planning scenario. The results have been obtained with coverage simulations in the Basque Country, a region in northern Spain currently served with 64 transmitters of a traditional broadcast network. The results conclude that a LPLT network would require 3.3 more centers for providing the same coverage as the current HPHT network at a cost three times higher. Also, it has been observed that the current HPHT network fails to give portable and mobile coverage numbers close to real-service targets in urban areas. In those cases, the approach with lower number of sites and cost is a mixed HPHT + LTLP network, where a set of LPLT transmitters complement the coverage provided by the HPHT network. [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]

In this paper, the hierarchical modulation (HM) technique is adopted in a single frequency network (SFN) to provide both global and local information. In order to mitigate the interlayer interference and intercell interference, we develop a low-complexity successive interference cancellation (SIC) algorithm for the coded HM signals in the SFN. The proposed decoding algorithm can be applied to different soft-decision channel coding schemes (e.g., Turbo codes, LDPC codes) under various channel profiles. We analyzed the decoding complexity of the proposed algorithm, and evaluated the bit error rate performance. The simulations show that the new decoding algorithm can offer up to 0.7 dB carrier to noise ratio \((C/N)\) gain compared with the traditional SIC approach under different channel models, while providing the comparable performance (up to 95% decoding complexity savings) with the multilayer iterative decoding approach. The performance evaluation and decoding complexity comparisons indicate that the proposed structured SIC approach offers a good performance-complexity trade-off, especially for the HM-based SFN scenarios. [ABSTRACT FROM PUBLISHER]

Current digital terrestrial television networks make use of either single frequency networks (SFN) or multifrequency networks (MFN). These network topologies are not ideally suited for delivery of both global and local services in an efficient way. MFNs enable the efficient transmission of local services but need a significant amount of frequency spectrum. The basic principle of SFNs is that all transmitters radiate the same signal synchronized in time and frequency, therefore are especially suitable for global services due to mutual support of the signal by multiple transmitters. Without violating the SFN principle, local services meant to address sub-regions of an SFN must therefore be transmitted throughout the whole network, causing inefficient distribution of local services. This paper describes the complementary techniques adopted by the next generation mobile broadcasting standard digital video broadcasting—next generation handheld for providing global and local contents in SFN topologies: hierarchical modulation (H-LSI) and orthogonal local services insertion (O-LSI) techniques. H-LSI uses hierarchical modulation to transmit local services on top of the global services in areas close to the transmitters, by transmitting the local services in the low priority stream and the global services in the high priority stream. The O-LSI scheme specifies groups of OFDM subcarriers in specific OFDM symbols for the exclusive use of particular transmitters to transmit local services. For both techniques, the transmission of local content through the whole SFN network can be scheduled in a way that different local areas do not interfere with each other. In addition to the description of both H-LSI and O-LSI schemes, the applicability of these approaches in terms of network topologies, implementation issues, and performance evaluation are analyzed. [ABSTRACT FROM PUBLISHER]

Single carrier frequency-domain equalization (SC-FDE) modulations are known to be suitable for broadband wireless communications due to their robustness against severe time-dispersion effects and the relatively low envelope fluctuations of the transmitted signals. In this paper, we consider the use of SC-FDE schemes in broadcasting systems. A single frequency network transmission is assumed, and we study the impact of distinct carrier frequency offset (CFO) between the local oscillator at each transmitter and the local oscillator at the receiver. We propose an efficient method for estimating the channel frequency response and CFO associated to each transmitter and propose receiver structures able to compensate the equivalent channel variations due to different CFO for different transmitters. Our performance results show that we can have excellent performance, even when transmitters have substantially different frequency offsets. [ABSTRACT FROM AUTHOR]

When DVB-T2 uses the option of (distributed) multiple-input single-output transmission mode, a pair of Alamouti-encoded orthogonal frequency division multiplex signals is transmitted simultaneously from two spatially separated transmitters in a single frequency network. Since both transmitters have their own local oscillators, two distinct carrier frequency offsets (CFOs), one for each transmitter-receiver link, occur in the received signal due to the frequency mismatch between the local oscillators. Unfortunately, the multiple CFOs cannot be compensated simultaneously by merely adjusting the carrier frequency at the receiver side, so intercarrier interference (ICI) always exists. In this paper, we present an iterative receiver design to combat multiple CFOs for DVB-T2 application. To estimate both multiple CFOs and channels jointly without sacrificing the spectral efficiency, the joint maximum likelihood (ML) estimation based on the soft information from the channel decoder is used. The proposed receiver performs the iterative joint processing of the data detection, ICI cancelation, and joint ML estimation of the multiple CFOs and channels by exchanging the soft information. We also show that the complexity of the joint ML estimation can be reduced significantly by transforming a huge matrix pseudo-inversion into two sub-matrix pseudo-inversions. The performances are evaluated via a full DVB-T2 simulator. The numerical results show that the mean-squared error performance of the joint ML estimation is closely matched with the Cramér-Rao bound. Furthermore, the resulting bit error rate performance is enhanced in a progressive manner and is able to approach the ideal CFOs-free performance within a few iterations. [ABSTRACT FROM AUTHOR]

Several previous studies have demonstrated that additional low-rate data can be transmitted in Advanced Television Systems Committee (ATSC) terrestrial digital television (DTV) systems by modulating the polarity of the transmitter identification (TxID) signal. Previously proposed additional-data transmission schemes can offer an additional reliable transmission channel, and thus they have a very large coverage area compared to that of a DTV signal. Unfortunately, as the cost of a reliable transmission, they have a limitation in their maximum data rate. In this paper, we propose a new additional data transmission scheme based on sequence phase modulation (SPM) to increase the data rate. The proposed scheme exploits not only the polarity but also the phase of a TxID signal, and thus it significantly enhances the data rate compared to conventional schemes. [ABSTRACT FROM PUBLISHER]

To solve practical challenges for implementing deep learning-based algorithm in MIMO signal detector such as handling complex number or designing proper neural network for a specific communication system, (Baek et al., 2019) has proposed candidate implementation methodologies with simple verification experiments. According to (Baek et al., 2019), it was shown that the proposed algorithms can achieve the optimal ML performance. However, due to the lack of explanation on the experimental environment, it is difficult for readers to reproduce the presented experiments and obtain the same results. This document precisely explains on the experimental environments of (Baek et al., 2019) including the exact channel profiles. [ABSTRACT FROM AUTHOR]

Wireless positioning using digital television (DTV) signals is a promising complementary to global positioning system due to high transmission power and wide coverage of DTV transmitters. Without changing the current infrastructure of Chinese DTV broadcasting network, this paper proposes a positioning scheme using time-domain synchronous (TDS) orthogonal frequency division multiplexing (OFDM) signals in single-frequency networks. The transmission parameter signaling (TPS) embedded in the TDS-OFDM signals is time-division multiplexed as orthogonal frequency-domain pilots, and then the time-domain pseudorandom noise sequence and the frequency-domain TPS are jointly utilized for accurate time of arrival (TOA) estimation for each transmitter. The theoretical bound of the TOA estimation accuracy is also derived. The proposed wireless positioning scheme has no impact on the normal TV program reception. Simulation results show that the positioning accuracy of less than 1 m can be achieved in SFN scenarios. The idea of time-frequency joint positioning can also be applied to other OFDM-based wireless systems. [ABSTRACT FROM PUBLISHER]

This paper describes the results of two extensive measurement campaigns for evaluating the potential impact of scattered signals from wind turbines on terrestrial DTV reception quality in the UHF band. A detailed description of the different propagation channels encountered is provided. Furthermore, empirical threshold carrier-to-noise requirements for Quasi Error Free reception in the DVB-T system in the area of influence of a wind farm are presented, and the situations where a significant degradation can be found are identified and characterized. [ABSTRACT FROM AUTHOR]

Digital on-channel repeater (DOCR) is regarded as a desirable solution to effectively build a wide-area network of mobile terrestrial-digital multimedia broadcasting (T-DMB) services. On the other hand, the DOCR mainly suffers from interference effects caused by a strong feedback signal and a time-varying channel dispersion. In this paper, we propose a novel DOCR for use in the T-DMB system in order to mitigate effectively both interference effects. First, we present an energy equalizer using the scarce pilot structure of T-DMB system to estimate a channel state information on every OFDM symbol. An optimum frequency domain channel estimation (FDCE) algorithm is then derived for the energy equalizer. In addition, a moving average filter (MAF) is employed to mitigate the phase distortion of truncated equalizer coefficients in deep null channel. Finally, in the performance evaluations, it is shown that the optimum FDCE outperforms a perfect FDCE. It is also shown that the DOCR equipped with the proposed interference cancellation can solve the problems caused by a limited channel information update, a phase distortion of the equalizer, and a residual feedback signal. [ABSTRACT FROM PUBLISHER]

A hierarchical modulation method is proposed for providing local content in a hybrid satellite and terrestrial single frequency network such DVB-SH. The hierarchical modulation is used to transmit both global and local content in terrestrial transmitters. The global content is transmitted with high priority layer of the hierarchical modulation, and the local content is modulated with the low priority layer of the hierarchical modulation. The satellite transmits global content only. The performance of the hierarchical system for both global and local content is analyzed. [ABSTRACT FROM AUTHOR]

High level combining is a practical way to upgrade existing FM transmitters to IBOC. Very well understood, with readily available 10 dB couplers, it is a very attractive method with which to upgrade even the highest power levels in the field. Unfortunately, if offers only a combining efficiency of 83%, as 90% of the IBOC power is wasted into a dummy load, along with 10% of the generated FM power. Additionally, the power headroom demanded from the FM transmitter is proving to be an unsurpassable requirement for some existing sites ready to upgrade. This paper presents an innovative combining technique that minimizes the FM and IBOC power loss in high level combining. Instead of combining two totally incoherent signals with its known resulting losses, this method first achieves partial coherence of the signals, and only then combines them at an optimum coupling ratio. A system implemented this way offers two main benefits; a higher overall system efficiency, and the elimination of the need for FM headroom. Though the paper focuses on the particular case of FM HD radio upgrade, this technique can also be used whenever low loss is needed when combining dissimilar signals. [ABSTRACT FROM AUTHOR]