Evaluation performance analysis of DVB-T2 in a SFN network

Single Frequency Network(SFN) transmission mode in Long Term Evolution(LTE) can be used to deliver Multimedia Broadcast Multicast Service(MBMS) business in the form of sharing wireless resources. It has negative effect on the spectral efficiency while the allocation of resources in SFN mode refers to the worst signal user. This paper introduces a novel transmission mode named Mixture Mode(MIX) for MBMS transmission, and proposes an optimized switching mechanism denominated MIX-SFN-PTP(MSP) to dominate the switching among MIX, SFN and Point-to-point(PTP). PTP and SFN are incorporated in MIX, and a fast-select algorithm working in a greedy manner is designed to determine the ways in which users receive the MBMS business. MIX and MSP are evaluated through simulation experiments. The results show that MIX is able to obtain higher spectral efficiency compared with SFN transmission mode, and MSP can economize more wireless resources than traditional algorithm in the case that users have subpar signal.

Single frequency networks (SFN) broadcast is an efficient method to provide broadcast services in cellular networks. How to select broadcast services by the SFN operation to trade off between the occupied bandwidth and the SFN performance including spectrum efficiency and broadcast service continuity is a new problem. To the best of our knowledge no solutions have been proposed to solve this problem so far in the literature. We define the problem of SFN broadcast services selection as a knapsack problem and solve it to minimize the occupied bandwidth while at the same time guaranteeing the SFN performance. Based on the solution, several SFN broadcast services selection algorithms are proposed which vary in the reselection policy. Numerical results show that our proposed algorithms are applicable to different cases with different system requirements and in particular, that the semi-dynamic-SFN broadcast services selection algorithm is an efficient solution in general.

This paper presents the results of laboratory tests simulating the reception in a Single Frequency Network (SFN) with ATSC on commercial receivers. The results of the commercial receivers are important because the viability of the SFNs with ATSC depends mainly of the performance of the receivers. Additionally, the basic implications of the results on the SFNs design are presented. Mexico officially adopted ATSC for Digital Terrestrial Television (DTT) service more than 10 years ago, but the analog transmissions stopped until December 31, 2015. The results of these tests can contribute to the planning of SFNs with ATSC. ATSC does not use OFDM modulation unlike others DTT systems. For this reason, the operation of a SFN with ATSC depends primarily on receiver equalizer capabilities. However, the performance of the receivers have improved over the years. The tests focus on the relationship between power and delay of the two signals received on the SFN, and the methodology includes the simulation of three reception environments: without multipath, outdoor reception and indoor reception.

Digital terrestrial television systems (DVB-T) using single frequency networks (SFN) based on OFDM modulation schemes have been deployed during the last years. Such SFN topology make it possible to increase the number and quality of services offered due to their more efficient use of the spectrum compared to multiple frequency networks (MFN). Moreover, SFN can cut down on the number of transmitters along with their powers because of the internal gain of the network, saving overall deployment and maintenance costs, and even achieving coverage improvements or a decrease of the outage probability over larger geographical areas through the reuse of frequencies. In this work, an approach to analyze and improve the coverage of a SFN over the most populated regions with the least possible economic investment is proposed, considering several strategies to synchronize and combine the signals at the receiver side and using a hybrid algorithm, mixing up the real and binary versions of the Particle Swarm Optimization algorithm (PSO), to optimize the static delays, gains and orientations for each SFN transmitter and decide whether each sector antenna must be active or not.

DVB-T2 broadcasting with a single frequency network (SFN) allows an efficient management of frequency utilization and extends the coverage area, which will enable more people to view a broadcast. The SFN mode also increases the concentration of the signal in overlap areas. However, some difference of overlap areas in actual use of SFN networks may have some degradation of the received signal due to the effect of the SFN. In this research, we analyze SFN broadcasting in SISO mode. This paper represents the effects of delays on the SFN signal over different delay times within the guard interval (GI) by analyzing the minimum reception threshold. The analysis of received signal power, MER, bBER, LBER, and noise margin are studied using an actual digital television transmitter for the experiment. The results show that the minimum thresholds for a delay time at 0 microseconds will require higher receive signal power than other delay times within the GI. The results of this experiment are useful in designing the SFN network and make it possible to determine the appropriate C/N threshold for the design of the digital terrestrial television network.

The single frequency network (SFN) has been assumed worldwide by telecommunication operators to save radio frequency resources and homogenize the network. Its applications have transcended the digital terrestrial television and digital radio to become part of the key techniques of the broadband and broadcast convergence for LTE-A, 5G and beyond. However, the transition from a multi frequency network (MFN) to an SFN involves multiple measurement campaigns and tuning of the network to achieve the expected up-performance and quality of service. This paper aims to propose a machine learning model to predict the SFN performance from the legacy MFN parameters. The model is based on regression and classification machine learning algorithms concatenated in three consecutive stages to predict SFN electric-field strength, modulation error ratio and gain. The training and test processes are performed with a dataset of 389 samples from an SFN/MFN trial in Ghent, Belgium. The best performance is obtained with concatenating gradient boosting, random forest, and linear regression, which allows predicting the SFN electric-field strength with an R-2 of 92%, the modulation error ratio with 95%, and SFN gain with 87% from only MFN and position data. Besides, the model allows classifying the data points according to positive or negative SFN gain with an accuracy of 93%.

In this work, the usefulness and limitations of a planning tool that combines a propagation prediction method and a modern heuristic technique when applied to improve the coverage area in single frequency networks (SFN) is presented. The propagation prediction method uses 3D digital terrain maps along with a propagation model to estimate the contribution of any transmitter of the SFN at each location within the region in which the SFN is intended to be deployed, given in terms of parameters such as the received power and propagation delay. Furthermore, a particle swarm optimization (PSO) algorithm is used to optimize the transmission parameters of any of the transmitters within the SFN, including transmitters delay or gain for their sector antennas, in order to exploit the multipath tolerance in OFDM receivers. Preliminary results comparing the performance of different PSO schemes considering as the canonical problem a SFN consisting of eighteen transmitters, in which transmitters and receivers have been simplified, are reported and discussed. Moreover, results considering sector and directive antennas at the transmitter and receiver sides, respectively, are also included.

Terrestrial broadcasting signals have been recognized as promising candidates for positioning and navigation needs. However, in some terrestrial broadcasting networks, which are usually single frequency networks, the transmitter confusion problem poses a huge obstacle to almost all positioning algorithms. Without knowing the transmitter identities, measurements can't be associated to transmitters coordinates properly, thus leaving receiver coordinates unable to be estimated. Meanwhile, as the exact transmission delay is usually hard to estimate, the time difference of arrival (TDoA) based positioning is widely used. In this paper, a novel TDoA based localization method is proposed to realize positioning in single frequency networks. With the proposed method, the receiver can estimate its own position when transmitter identities are missing from the signals. Simulation results verify the feasibility and accuracy of the method and discussions regarding its properties are given.

In a Single Frequency Network (SFN) for Advanced Television Systems Committee (ATSC) terrestrial digital television (DTV) system, the interferences induced by the multiple transmitters and/or repeaters using same frequency are unavoidable. To ease the interference handing in the SFN for ATSC DTV system, transmitter identification (TxID) signal is recommended in the ATSC terrestrial DTV system. The TxID signal is embedded in the ATSC DTV signal and transmitted from each transmitter and repeater within the SFN and in ATSC recommended practice (RP) A/111, Kasami sequence is recommended as the TxID signal. In this paper, we propose an additional data transmission scheme using the TxID signal. In the proposed scheme, the Kasami sequence not only acts as the conventional TxID of the SFN for ATSC terrestrial DTV system but also carriers the additional data bits on its polarity and the code phase.

In single frequency network (SFN), there exist some special long delay spread channels as well as conventional multi-path channels. For pilot-aided orthogonal frequency division multiplex (OFDM) systems, channel estimation is usually accomplished by interpolation with pilots. However, few pilot subcarriers exist within coherent bandwidth under the long delay spread channels in SFN. In this case, conventional interpolation methods cannot work properly. This paper proposes a sine-wave based frequency domain interpolation method for channel estimation of pilot-aided OFDM systems in SFN. As simulation results show, the proposed method gives accurate channel estimation under the long delay spread channels, whereas the mismatched Wiener interpolation filter (WIF) estimates channel response inaccurately. Moreover, the proposed method performs well under conventional multi-path channels, especially for systems which adopt high order modulations.

This paper proposes several realistic fading channel models to describe the signal distortions that arise in single frequency network (SFN) environments. The proposed models characterize ultra-high frequency (UHF) wireless channels based on measurements from operating networks in metropolitan areas. In this paper, the unique features of SFN transmission are identified compared to the conventional, single antenna transmission channels. The impacts of urban propagation, tower configuration, and mobile and terrain effects are considered based on the tapped delay line structure. The proposed models can provide a useful reference to facilitate the SFN system design, network planning, verification, and receiver performance test. Free MATLAB source code of the fading simulator is available at <uri xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">https://github.com/ETRI-KMOU/FadingChannelSimulator</uri> .

Single frequency networks (SFN) are usually considered to deploy OFDM modulation based digital broadcast systems, exploiting the multipath tolerance of the OFDM receivers, which are capable of combining signals coming from several transmitters with different propagation delays. In this work, a planning tool is proposed to improve the coverage area in SFN networks, optimizing transmission parameters such as the transmitters delay or power, using 3D digital terrain maps along with a propagation prediction tool to estimate the power received at each location inside the coverage area. A heuristic particle swarm optimization algorithm is used (PSO) to optimize transmission parameters. The approach proposed makes it possible to consider several configurations regarding both transmitters and receivers. Preliminary test results are shown for a SFN with eighteen transmitters and omnidirectional radiators at both sides that demonstrate the usefulness of the approach. Furthermore, results considering receivers with directive antennas as well as transmitters with sectored antennas are also included and discussed.

In OFDM based Single Frequency Networks (SFNs) such as Digital Audio Broadcasting (DAB) and Digital Video Broadcasting (DVB), the mobile receiver is provided by the same signal from several synchronous transmitters at the same carrier frequency. This transmitter diversity structure makes SFNs very efficient in fading channels with an excellent spectrum saving, and very good power utilization over the service area. However, depending on the position of the mobile within the service area, these signals arrive with different delays causing possible echoes at the receiver. These echoes contribute to both the useful and the interfering parts of the signal. As the average received power in radio channels is a stochastic process, such contribution creates correlation between the different components of the Signal-to-Interference Ratio (SIR). In broadcasting practice, correlation was not taken into account when estimating the distribution of the SIR and the local coverage probability. This paper considers the effect of correlation on the estimation of the SIR and the coverage probability in OFDM based SFNs. Analyses are provided to show that in some situations the estimation error can be considerable when neglecting this correlation. To obtain a better estimation, the correlation coefficient between the total useful and total interfering parts of the received signal is first evaluated and then used as a correction factor in estimating the mean and standard deviation of the SIR. The obtained results show that such method can significantly reduce the estimation error of local coverage probability without increasing the computation complexity.

The broadcasting of TV programmes to mobile phones can be enabled by the newly developed technology called Digital Video Broadcasting-Handheld (DVB-H). Because of the scarcity and cost of frequency resources, frequency reuse needs to be considered when rolling out DVB-H networks. By simulcasting the same content from several transmitters, a Single Frequency Network (SFN) can provide good coverage and good frequency efficiency. In this paper, the performance of densified DVB-H SFN networks is analysed in terms of the coverage probability under different coverage requirements with and without frequency reuse. A dichotomy searching approach is used to determine the optimal cell radius for a cell in a densified DVB-H SFN for a given network topology. Based on the optimal cell radius map and a SFN gain map generated from the simulation results, guidelines are proposed on how to avoid the potential pitfalls in configuring the parameters of a densified DVB-H SFN network and optimise its parameters in terms of minimising the cost of the network for a range of predefined network parameters.

The multi-hop ad-hoc networking paradigm is expected to be a key feature in future wireless communication systems. In a typical data broadcast scenario, multi-hop ad-hoc routing protocols allow devices (called nodes in this paper) to communicate and form networks in a manner to enable them to successfully communicate and share information with all other nodes. To ensure maximum reachability in a multi-hop network, the concept of cooperative diversity, in which multiple nodes cooperate to transmit the same data to a destination, can be applied. The cooperative diversity is best exploited with the use of Single Frequency Networks (SFNs), also known as a form of Macro-diversity. This work comprises of a design and analysis of an SFN based distributed cooperative routing protocol (SFNDCRP) for multi-hop ad-hoc networks with a focus on routing initiation phase with CSMA as a synchronization mechanism. The proposed protocol is proactive and incurs minimum per packet delay. The total delay in routing initiation phase for a network of n nodes is identified as a problem of n2+2n. A delivery rate or reachability improvement of up-to 36% points for a node is observed for the SFN based protocol as compared to a non-SFN based protocol. For synchronization, a CSMA MAC protocol is deployed for which a deficiency of only less than 0.1 percent exists in the measurements due to collisions in the network.