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This paper studies the secure transmission in a multiuser broadcast channel where only the statistical channel state information of the eavesdropper is available. We propose to apply secret dirty-paper coding (S-DPC) in this scenario to support the secure transmission of one user and the normal (unclassified) transmission of the other users. By adopting the S-DPC and encoding the secret message in the first place, all the information-bearing signals of the normal transmission are treated as noise by potential eavesdroppers and thus provide secrecy for the secure transmission. In this way, the proposed approach exploits the intrinsic secrecy of multiuser broadcasting and can serve as an energy-efficient alternative to the traditional artificial noise (AN) scheme. To evaluate the secrecy performance of this approach and compare it with the AN scheme, we propose two S-DPC-based secure transmission schemes for maximizing the secrecy rate under constraints on the secrecy outage probability (SOP) and the normal transmission rates. The first scheme directly optimizes the covariance matrices of the transmit signals, and a novel approximation of the intractable SOP constraint is derived to facilitate the optimization. The second scheme combines zero-forcing dirty-paper coding and AN, and the optimization involves only power allocation. We establish efficient numerical algorithms to solve the optimization problems for both schemes. Theoretical and simulation results confirm that, in addition to supporting the normal transmission, the achievable secrecy rates of the proposed schemes can be close to that of the traditional AN scheme, which supports only the secure transmission of one user. [ABSTRACT FROM PUBLISHER]

A memoryless bivariate Gaussian source is transmitted to a pair of receivers over an average-power limited bandwidth-matched Gaussian broadcast channel. Based on their observations, Receiver 1 reconstructs the first source component while Receiver 2 reconstructs the second source component both seeking to minimize the expected squared-error distortions. In addition to the source transmission digital information at a specified rate should be conveyed reliably to Receiver 1–the “stronger” receiver. Given the message rate we characterize the achievable distortions region. Specifically, there is an ${\sf SNR}$ -threshold below which Dirty Paper coding of the digital information against a linear combination of the source components is optimal. The threshold is a function of the digital information rate, the source correlation and the distortion at the “stronger” receiver. Above this threshold a Dirty Paper coding extension of the Tian-Diggavi-Shamai hybrid scheme is shown to be optimal. [ABSTRACT FROM AUTHOR]

Due to the great demand of throughput and reliability for multimedia applications in Fifth Generation (5G) networks, many broadcasting systems adopt the Millimeter Wave (mmWave) technology to address the lack of the spectrum resources. As one of 5G-PPP projects, Internet of Radio Light (IoRL) project adopts 40GHz mmWave band to support a high-speed and stable Ultra-High-Definition (UHD) television broadcasting service in the indoor environment. Because of the high frequency property, mmWave bands usually suffers from the high path loss and the penetration loss. Thus, in order to overcome these issues, directional antennas are employed to provide additional power gain while increasing transmission distance. However, the mmWave with directional antennas brings additional problems, such as limited transmission angle and more multipath effects. Therefore, in this paper, for better understanding of impact factors on the signal quality and transmission coverage of the directional 40GHz mmWave band in the indoor environment, a measurement campaign is introduced in detail and the channel characteristics are measured and analysed in varying cases. The mainly concerned characteristics are path loss, shadow fading, average Power Delay Profile (PDP), Root-Mean-Square (RMS) delay spread, arrival rate and coherence bandwidth. All Measured characteristic values are summarised in three tables at the end of this paper. Besides of these, as a reference of channel analysis and a metric of signal quality and effective coverage, Error Vector Magnitude (EVM) of received signal in each case is measured and discussed. Moreover, a simulation is performed based on a statistical channel model to validate the measured results. [ABSTRACT FROM AUTHOR]

This paper presents the research and implementation of a China Digital Radio (CDR) experimental network in Hubei, China with two FM-CDR transmitting stations and four FM-band channels. To study the coverage discontinuity problem in a large service area, the experimental network employs an intelligent networking solution that incorporates multiple service channels carrying Broadcast and Data Services (BADS) and a Common-Regional-Information Channel (CRIC) carrying both service data and system information. The electronic service guide (ESG) carried by CRIC can inform the receivers about the available contents from current and adjacent stations, which can significantly improve the service quality in the overlapping areas, especially under mobile reception environment. Two RF tuners are used in the receiving terminals to access the CRIC, and the BADS channel, respectively. This paper first presents the frequency analysis and coverage tests of the experimental network, and then summarizes the coverage performances with different transmission parameter combinations. The goal is to gain experience in frequency planning, coverage prediction, as well as supportable services of CDR digital audio broadcasting. [ABSTRACT FROM AUTHOR]

In this paper, the scheme that combines LDM (Layered Division Multiplexing) with the FDM (Frequency Division Multiplexing) scheme based on BST-OFDM (Band Segmented Transmission - Orthogonal Frequency Division Multiplexing) is proposed for the next-generation DTTB (Digital Terrestrial Television Broadcasting). The proposed LDM-BST-OFDM scheme provides a more effective frequency utilization of the stream for fixed reception. The performance of the proposed scheme is evaluated by computer simulations where the effectiveness of proposed scheme for fixed reception is shown. Although LDM-BST-OFDM improves the performance, dedicated receivers that can demodulate symbols multiplexed by LDM are required. In this paper, LDM-BST-OFDM using punctured LDPC code is proposed, which can decode the stream for fixed reception even if symbols multiplexed by LDM are not demodulated. The reception characteristics of the proposed scheme are evaluated by computer simulations. [ABSTRACT FROM AUTHOR]

With the proliferation of portable devices, the exponential growth of the global mobile traffic brings great challenges to the traditional communication networks and the traditional wireless communication technologies. In this context, converged networks and cache-based data offloading have drawn more and more attention based on the strong correlation of services. This paper proposes a novel popular services pushing and caching scheme by using converged overlay networks. The most popular services are pushed by terrestrial broadcasting networks. And they are cached in ${n}$ router-nodes with limited cache sizes. Each router-node only interconnects with its neighbor nodes. Users are served through the router’s WiFi link. If the services requested are cached in the routers, the user can be immediately responded; otherwise, the requests can be responded through the link from cellular stations to the router. In the proposed scheme, the cache size of the router, the maximum number of requests each router can serve, and the whole-time delay are limited. Three node-selecting and dynamic programming algorithms are adopted to maximize the equivalent throughput. Analytical and numerical results demonstrate that the proposed scheme is very effective. [ABSTRACT FROM AUTHOR]

Pedestrian Dead Reckoning (PDR) is a good alternative positioning method in Global Navigation Satellite Systems (GNSS)-challenged environments. It has the advantage in terms of infrastructure-independent, while the disadvantage is that, the estimated errors grow rapidly with time. The Digital Terrestrial Multimedia Broadcasting (DTMB) signals have strong transmission power, which contributes to better urban propagation and building penetration than GNSS signals. So, in this paper, an enhanced PDR algorithm aided with DTMB signals is proposed. In the study, a complete software-defined radio receiver is developed to estimate the Doppler speed and range information from DTMB signals. To reduce the accumulated errors of the PDR, the Extended Kalman Filter (EKF) algorithm is carried out to fuse the information of Doppler speed and ranging from the DTMB signals, as well as the information of walking speed and heading from the PDR. The results of the field tests showed that the 95% positioning error of the proposed algorithm is less than 3.94 m, while the PDR only is less than 9.19 m, which suggests the effectiveness of the proposed method to provide continuous positioning by fusing DTMB signals with PDR. [ABSTRACT FROM AUTHOR]

This paper provides a summary of media distribution in the 3GPP 5G System. We provide a status overview on the basics of 5G and in particular the Release 16 technologies on 5G Media Streaming and 5G Broadcast. Particular focus in this document are the recent Release-17 activities including extensions to 5G Media Streaming and 5G Broadcast. On the former, for example the integration of edge computing into media streaming is a major focus. On the latter, 5G Broadcast is extended to support co-existence of the technology with other broadcast technologies in the UHF band. A new set of functionalities is developed under the 5G Multicast–Broadcast Services (5MBS) umbrella work item. This includes new user service and system architecture functions to support broadcast and multicast throughout the 5G system. Particular focus in this paper are the radio layer and physical layer extensions to support point-to-multipoint delivery on top of New Radio (NR). We also touch briefly on the relevance of the 5G media distribution for third party ecosystems and industry with special focus on collaboration of media verticals and the 5G ecosystem. [ABSTRACT FROM AUTHOR]

Sliding window decoding has been employed as the decoding scheme of quasi-cyclic spatially-coupled low-density parity-check (QC-SC-LDPC) codes, with the decoding latency and complexity independent of the coupling length but proportional to the window size. The window size was empirically chosen at least three times the constraint length in previous works, which results in the preference of QC-SC-LDPC codes with small constraint length, to reduce the decoding latency and complexity in practical systems. However, the code design freedom and the decoder throughput are limited for these QC-SC-LDPC codes. In this paper, the optimal window size under the constraint of practical decoding complexity is analyzed employing multi-edge-type density evolution (MET-DE). It can be verified from the MET-DE analytical result that the optimal window size could achieve less than twice the constraint length for several edge spreading patterns, which largely loose this restriction in practical code design. Furthermore, it could be observed that besides the constraint length, the specific structure of the edge spreading pattern could affect the optimal window size as well, and thus the MET-DE analytical method for the optimal window size could effectively guide the design of QC-SC-LDPC codes in practical systems. Then an improved sliding window decoding scheme is proposed, including the optimal choice of window size and a parity-check based early termination scheme. Finally, the performance and robustness of the proposed sliding window decoding scheme for QC-SC-LDPC codes are demonstrated via simulation, with the decoding complexity at most twice as that of the conventional LDPC coded schemes. [ABSTRACT FROM AUTHOR]

This paper encompasses various topics for 5G-involved broadcasting under the common context converged distribution of 5G media. Particularly, two primary subtopics are addressed: An overlaid coexistence of 5G terrestrial broadcast and Advanced Television Systems Committee (ATSC) 3.0; and dual connectivity applications built on top of the convergence between digital broadcasting and 5G unicasting. In the first part, a viable, time-sharing co-transmission system is introduced to overlay 5G Broadcast and ATSC 3.0 frames in the same radio spectrum. The system is carefully designed to comply with current 5G and ATSC 3.0 standards, so that it does not require modifications in either ATSC 3.0 or 5G specifications. To help the future planning in a technical aspect, the reliability performance is in-depth compared between 5G Broadcast and ATSC 3.0 frames, and the motivation of tower overlaying is discussed as well. Subsequently in the $2^{\mathrm{ nd}}$ part, the convergence is in parallel explored with respect to the dual connectivity. To settle a broad-ranged consensus for future convergence, various possible use cases are proposed in an application aspect. Technical, conceptual proposals and implementations are presented, specifically related to edge caching; 8K streaming (with a working prototype); large-scale software updating; data security; and location tracking. We hereby point out how dual connectivity can contribute to realistic scenarios. In turn, the scope of convergence use cases is desirably expanded, so that would encourage the initiatives bridging 5G and broadcasting into practice. [ABSTRACT FROM AUTHOR]

Broadcasting signals have been recognized as promising candidates for navigation and positioning needs. However, in most single frequency broadcasting networks, the transmitter confusion problem poses a huge obstacle. Not holding the transmitter identities, the receiver cannot determine the distance to the transmitters, let alone its own position. What’s worse, considering the existence of multipath propagation, the receiver is unable to distinguish line of sight (LOS) components from non line of sight components, which makes positioning even harder. In this paper, a two-step method is proposed to solve the positioning problem in single frequency networks (SFNs) under multipath propagation yet with direct path. First, a probability approach is proposed to identify all LOS components iteratively. Then, it is proved in this paper that a receiver can determine its position when receiving LOS signals from at least five transmitters without the knowledge of transmitter identities. Detailed analysis is carried out in this paper to derive error bounds and performance limits from different perspectives. Simulation results show that the proposed algorithm can achieve high accuracy of positioning across multiple environments. Besides, the proposed methodology is general, which can be used in any SFN or other wireless networks for positioning needs. [ABSTRACT FROM AUTHOR]

This paper presents a novel bluetooth low energy (BLE) protocol enabling a BLE node to perform RF fingerprint acquisition by measuring the received signal strength (RSS) from its neighboring nodes and simultaneously broadcast the acquired fingerprint via its advertising packet. However, the fingerprint acquisition and broadcast process in a dense BLE network is very challenging owing to: 1) the likelihood of packet collision; and 2) the length-constrained packet. To this end, we exploit a compressive sensing (CS) framework allowing each node to acquire no more than $M$ M measurements from a very dense network, in which the number of nodes $N$ N is far greater than $M$ M . By aggregating the $M$ M -dimensional compressed fingerprint vector from $s

To protect military broadcasting against both hostile interference and eavesdropping, an artificial noise (AN) sheltered frequency hopping (FH) broadcasting (ANS-FHB) architecture is proposed in this paper, and the secrecy capacity is employed to measure its secrecy performance. Besides, considering the inevitable frequency mismatch after synchronization will degrade system secrecy in practical applications, the optimal transmitting power allocation (PA) for the confidential information (CI) and AN is provided to maximize secrecy capacity in presence of frequency mismatch. Moreover, to be adapted to various application scenarios, the proposed optimal PA scheme is further simplified according to the frequency synchronization ability and relative channel quality. The analysis and simulations show that the proposed ANS-FHB system can achieve a non-negative secrecy rate even when existing multiple eavesdroppers. In addition, the optimal power ratio of AN to CI shows a downward trend from one to zero as frequency mismatch increases to mitigate the secrecy loss. [ABSTRACT FROM AUTHOR]

In the public channels, it is desirable to transmit the common signals omnidirectionally to ensure cell-wide coverage. In Part I of this two-part paper, we develop low-cost closed-form omnidirectional precoding designs for a massive multiple-input multiple-output (MIMO) system equipped with a uniform rectangular array (URA). By formulating the omnidirectional transmission design for a general URA as a feasibility optimization problem, we derive an optimal solution based on the complementary set (CS) or the complete complementary codes (CCC). We prove that the precoding vectors based on the CS or CCC sequences can generate a perfectly omnidirectional power radiation pattern. Since both CS and CCC sequences are binary and constant-modulus, the proposed schemes are well suited to be implemented in the radio frequency analog domain with low hardware cost and suppressed peak-to-average power ratio. The numerical results validate the superior performance of the proposed schemes over the existing alternatives. [ABSTRACT FROM AUTHOR]

This paper presents a cache-based popular services pushing solution on high-speed train (HST) by using converged wireless broadcasting and cellular networks. Pushing and caching popular services on the HST to improve the capacity of the network is a very efficient way; and it can also bring a better user experience. The most popular services are transmitted and cached on the vehicle relay station of the train ahead the departure time in the proposed model. Then, the most popular services are broadcasted and cached on the User Equipment after all the passengers are on the train; the less popular services are delivered to the passengers by P2P mode through the relayed cellular network on the train. Specifically, we firstly use the dynamic programming algorithm to maximize the network capacity in limited pushing time, which can be converted to the 0–1 Knapsack problem. Furthermore, we propose three greedy algorithms to approximate the optimal solution on account of the high time complexity of dynamic programming when the input scale gets bigger. And simulation results show that the proposed popularity-based greedy algorithm performs well. Moreover, as the passengers may get on and off the HST when arriving at an intermediate station, a services rebroadcast algorithm is employed when more intermediate stations are considered. U-shaped distribution is adopted to indicate the number of passengers getting on and off the train. Simulations also show that the proposed rebroadcast algorithm can efficiently improve the capacity of the converged networks. [ABSTRACT FROM AUTHOR]

This paper proposes the optimal white point settings of consumer televisions observed in different viewing conditions. The ratings from visual experiments were modeled with a bivariate Gaussian distribution to predict the optimal white points. Under dark surround conditions, where there is no effect of lighting chromaticity, the averaged optimal white point was located at a correlated color temperature of 7346 K and a Duv of −0.0015. The optimal white point was shifted toward a higher color temperature compared to the current standards. The results also indicated that current white point settings of major television manufacturers are too bluish. Neither televisions that meet the current standards nor televisions in the market would appear as true white under the viewing conditions employed in this paper. Moreover, the optimal white point depended largely on viewing conditions. Image content and ambient lighting conditions were observed to be important factors that influence the perception of the white point. The research therefore proposed to automatically change the white point of the display based on the image content and the real-time measurements of the surrounding ambient light falling on the screen. Ultimately, this paper might be of interest to the industry as a basis for future deliberations on target white points for consumer televisions designed to provide a better color appearance. [ABSTRACT FROM AUTHOR]

Most applications of underwater acoustic sensor networks (UASNs) rely upon reliable location information of sensor nodes. However, the harsh underwater environment makes localization more challenging as compared to terrestrial sensor networks. This paper is concerned with a localization issue for UASNs, subject to clock asynchronization and node mobility. A hybrid architecture including autonomous underwater vehicles (AUVs), active and passive sensor nodes is designed, where AUVs act as anchor nodes to provide localization information for sensor nodes. In order to eliminate the effect of asynchronous clocks and compensate the mobility of sensor nodes, an asynchronous localization algorithm with mobility prediction is provided for active and passive sensor nodes. Then, two localization optimization problems are formulated as minimizing the sum of all measurement errors. To solve the localization optimization problems, iterative least squares estimators are designed. In addition, the convergence analysis and Cramé r–Rao lower bound for the localization errors are also provided. Finally, simulation results show that the proposed localization approach can reduce the localization time by comparing with the exhaustive search-based localization method. Meanwhile, the asynchronous algorithm in this paper can effectively eliminate the impact of the clock asynchronization and node mobility. [ABSTRACT FROM AUTHOR]

Digital audio broadcasting services transmit substantial amounts of data that is encoded to minimize bandwidth whilst maximizing user quality of experience. Many large service providers continually alter codecs to improve the encoding process. Performing subjective tests to validate each codec alteration would be impractical, necessitating the use of objective perceptual audio quality models. This paper evaluates the quality scores from ViSQOLAudio, an objective perceptual audio quality model, against the quality scores of PEAQ, POLQA, and PEMO-Q on three datasets containing fullband audio encoded with a variety of codecs and bitrates. The results show that ViSQOLAudio was more accurate than all other models on two of the datasets and performed well on the third, demonstrating the utility of ViSQOLAudio for predicting the perceptual audio quality for encoded music. [ABSTRACT FROM PUBLISHER]

In vehicular ad hoc networks (VANETs), beacon broadcasting plays a critical role in improving road safety and avoiding hazardous situations. How to ensure reliability and scalability of beacon broadcasting is a difficult and open problem, due to high mobility, dynamic network topology, hidden terminal, and varying density in both the time and location domains. In this paper, wireless resources are divided into basic resource units in the time and frequency domains, and a distributed and adaptive reservation based MAC protocol (DARP) is proposed to solve the above problem. For decentralized control in VANETs, each vehicle's channel access is coordinated with its neighbors to solve the hidden terminal problem. To ensure the reliability of beacon broadcasting, different kinds of preambles are applied in DARP to support distributed reservation, detect beacon collisions, and resolve collisions. Once a vehicle reserves a resource unit successfully, it will not release it until collision occurs due to topology change. The protocol performance in terms of access collision probability and access delay are analyzed. Based on the analysis, protocol parameters, including transmission power and time slots duration, can be adjusted to reduce collision probability and enhance reliability and scalability. Using NS-3 with vehicle traces generated by simulation of urban mobility (SUMO), simulation results show that the proposed DARP protocol can achieve the design goals of reliability and scalability, and it substantially outperforms the existing standard solutions. [ABSTRACT FROM AUTHOR]

Symbiotic radio (SR) is a promising technology for energy- and spectrum-efficient wireless communication, which exploits passive communication for Internet-of-Things (IoT) transmission and achieves a mutualistic spectrum sharing between the passive and active transmissions. In this paper, we study an reconfigurable intelligent surface (RIS) empowered symbiotic radio over a broadcasting system, i.e., a base station (BS) broadcasts signals to multiple primary receivers (PRs) under the assistance of an RIS, while the RIS also transmits information to an IoT receiver (IR) by riding over the broadcasting signals. We formulate a problem to minimize the BS’s transmit power by jointly optimizing the BS’s active precoding and the RIS’s passive beamforming, under the signal-to-noise-ratio constraints of the primary and IoT transmissions. However, the problem is challenging to be solved optimally, since the variables are coupled and the constraints are non-convex. An iterative algorithm based on block coordinated descent (BCD) and semidefinite relaxation (SDR) techniques is first proposed, and its convergence together with complexity are analyzed. Then, to tackle the problem of high computational complexity caused by SDR technique, we further propose an alternative algorithm based on generalized power method (GPM) technique. Simulation results validate that the proposed system outperforms the traditional broadcasting system without RIS. The GPM-based algorithm achieves nearly the same transmit power performance as SDR-based algorithm, with a significantly reduced computational complexity. [ABSTRACT FROM AUTHOR]

This paper proposes a broadcasting control system of intelligent air conditioners using the narrow-band power line carrier (PLC) (NPLC) technology. The communication protocol of Smart Energy Profile SEP 1.0 is implemented for the master station to issue commands to air conditioners over the power line. The function of demand response (DR) can also be executed via the proposed system. To verify the communication performance of control signal using the PLC technology, the field tests of NPLC over power lines and across transformers are executed. By integrating the PLC with the existing optical fiber network of the Distribution Automation System in the Taiwan Power Company, the Hybrid Communication System for Smart Grid applications is built and tested to support the control of air conditioners and the DR programs. It is found that the energy conservation by reducing the system peak load can be achieved when the proposed system is applied for the remote thermostat settings of air conditioners in the commercial section. The power consumption of various types of loads can also be collected and reported to the control center using the two-way communication provided by the proposed system. [ABSTRACT FROM PUBLISHER]

In this paper, we study linear encoding for a pair of correlated Gaussian sources transmitted over a two-user Gaussian broadcast channel in the presence of unit-delay noiseless feedback, abbreviated as the GBCF. Each pair of source samples is transmitted using a linear transmission scheme in a finite number of channel uses. We investigate three linear transmission schemes: A scheme based on the Ozarow–Leung (OL) code, a scheme based on the linear quadratic Gaussian (LQG) code of Ardestanizadeh et al., and a novel scheme derived in this paper using a dynamic programming (DP) approach. For the OL and LQG schemes we present lower and upper bounds on the minimal number of channel uses needed to achieve a target mean-square error (MSE) pair. For the LQG scheme in the symmetric setting, we identify the optimal scaling of the sources, which results in a significant improvement of its finite horizon performance, and, in addition, characterize the (exact) minimal number of channel uses required to achieve a target MSE. Finally, for the symmetric setting, we show that for any fixed and finite number of channel uses, the DP scheme achieves an MSE lower than the MSE achieved by either the LQG or the OL schemes. [ABSTRACT FROM AUTHOR]

This paper focuses on the problem of broadcasting information in the most efficient manner in a large 2-D ad hoc wireless network at low SNR and under line-of-sight propagation. A new communication scheme is proposed, where source nodes first broadcast their data to the entire network, despite the lack of sufficient available power. The signal’s power is then reinforced via successive back-and-forth beamforming transmissions between different groups of nodes in the network, so that all nodes are able to decode the transmitted information at the end. This scheme is shown to achieve asymptotically the broadcast capacity of the network, which is expressed in terms of the largest singular value of the matrix of fading coefficients between the nodes in the network. A detailed mathematical analysis is then presented to evaluate the asymptotic behavior of this largest singular value. [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]

Device-to-device (D2D) communications refer to direct communications between two or more devices without transferring data through the base station or other infrastructure. For synchronous D2D communication systems in most recent researches and development, orthogonal frequency-division multiple access (OFDMA) or single-carrier frequency-division multiple access (SC-FDMA) is considered to increase the communication coverage and to maintain the similarity with the cellular communication systems. One important design consideration for OFDMA-based (or SC-FDMA-based) D2D communication systems, particularly in an ad-hoc network mode, is the in-band emission effect, which corresponds to the mutual interference between different signals over other subchannels in the same time slot. To avoid interference from other transmitters or to other receivers, a transmitter may perform carrier sensing, which allows for transmission only when the measured interference is below the given threshold. Since the characteristics of the performance degradation due to other-channel interference (OCI) can be quite different from those by cochannel interference (CCI), the interference measurement must be carefully considered for carrier sensing in OFDMA-based D2D communication systems. This paper discusses physical carrier sensing for interference management in D2D group-casting or broadcasting systems and proposes a mechanism that efficiently avoids the interference from other subchannels. More specifically, outage probability is derived by taking both OCI and CCI into account and is then employed as a reference for the carrier sensing level in the course of selecting the resource blocks (RBs) for D2D communication. We demonstrate that our proposed carrier sensing scheme can significantly increase the areal capacity subject to the given target outage performance. [ABSTRACT FROM PUBLISHER]

In this paper, we consider a multiuser multiple-input multiple-output (MIMO) decode-and-forward (DF) relay broadcasting channel (BC) with single source, multiple energy harvesting (EH) relays, and multiple destinations. All the nodes are equipped with multiple antennas. The EH and information decoding tasks at the relays and destinations are separated over the time, which is termed as the time switching scheme. As optimal solutions for the sum-rate maximization problems of BC channels and the MIMO interference channels are hard to obtain, the end-to-end sum rate maximization problem of a multiuser MIMO DF relay BC channel is even harder. In this paper, we propose to tackle a simplified problem, where we employ the block diagonalization (BD) procedure at the source, and we mitigate the interference between the relay-destination channels using an algorithm similar to the BD method. In order to show the relevance of our low complex proposed solution, we compare it with the minimum mean-square error (mmse) solution that was shown in the literature to be equivalent to the solution of the sum-rate maximization in the MIMO broadcasting interfering channels. We also investigate the time division multiple access (TDMA) solution, which separates all the information transmissions from the source to the relays and from the relays to the destinations over time. We provide the numerical results to show the relevance of our proposed solution, in comparison with the no co-channel interference case, the TDMA-based solution, and the mmse-based solution. [ABSTRACT FROM PUBLISHER]

In this paper, a cooperative spatial modulation (SM) based non-orthogonal multiple access (NOMA) scheme with simultaneous wireless information and power transfer is proposed. In particular, NOMA is applied at the base station (BS) and the near user (U1) acts as an energy harvesting full-duplex relay to assist the far user (U2). The data bits of U1 and U2 are mapped into SM symbols and amplitude/phase modulation symbols, respectively. Furthermore, the rate of U1 is maximized while satisfying the target rate of U2 by jointly designing the power allocation coefficient, power-splitting ratio, and transmit power of U1. To solve the non-convex problem, a successive convex approximation-based iterative algorithm is developed. Finally, numerical results reveal that the proposed scheme can achieve the superior performance compared to existing schemes. [ABSTRACT FROM AUTHOR]

Broadcasting is an essential operation in wireless networks for disseminating the message from the source node to all other nodes. Unfortunately, the problem of Minimum Latency Broadcast Scheduling (MLBS) in duty-cycled wireless sensor networks is not well studied. In existing works, the construction of broadcast tree and the scheduling of transmissions are conducted separately, where a tree-based structure is used as the input of the scheduling algorithm. Relying on a pre-determined tree may result in a much large latency even using the optimal scheduling method. Thus, the MLBS problem in duty-cycled WSNs without the above limitation is investigated in this paper. First, to avoid relying on a pre-determined structure, a two-step scheduling algorithm is proposed to construct the broadcast tree and compute a collision-free schedule simultaneously. To the best of our knowledge, this is the first work that can integrate these two kinds of operations together. Second, a novel transmission mode, i.e., concurrent broadcasting, is first introduced for wireless networks and several techniques are designed to further improve the broadcast latency. Third, the multiple messages broadcasting and all-to-all broadcasting algorithms, which can generate a series of broadcast schedules independently without a pre-determined tree, are also proposed by taking care of the collisions in both the current and the previous broadcast schedules. Finally, the theoretical analysis and experimental results demonstrate the efficiency of the proposed algorithms in terms of latency. [ABSTRACT FROM AUTHOR]

Broadcasting plays a vital role in the consensus mechanisms of blockchain systems, since the consensus of each block must wait until the previous block is received by (nearly) all the nodes in the blockchain systems. Therefore, optimizing the performance of broadcasting can significantly improve the performance of the blockchain system. However, compared with other traditional P2P applications such as file downloading or video delivery, the broadcasting in blockchain has two new requirements, namely low redundancy and low propagation latency, which all the existing mechanisms (e.g. flooding, structural DHT etc.) can not meet well. In this paper, we propose Swift, a new broadcasting mechanism for blockchain systems. It optimizes the P2P topology construction and broadcast algorithm in the structured network based on unsupervised learning and greedy algorithm, effectively reducing the propagation latency of the blockchain P2P network while avoiding the waste of redundant bandwidth. We implemented a prototype of Swift and evaluated its performance on a testbed network that consists of 1000 blockchain nodes. The experimental findings show that Swift can reduce propagation latency by 19.8% with similar bandwidth consumption, generating an 18% increase in the throughput performance of the blockchain. Finally, with the increase in connections, Swift can simultaneously achieve low latency and maintain a relatively stable redundant bandwidth waste, instead of linearly increasing in flooding. [ABSTRACT FROM AUTHOR]

In this paper, we study the platoon cooperation in the multi-lane cooperative platoon scenario, where platoons move cooperatively and communicate with each other by cellular vehicle-to-everything (V2X) communication. The platoon cooperation is important for the interference management and communication reliability enhancement, yet it is difficult, since the platoon formation, subchannel allocation, and power control of each platoon interact with each other and influence those of other platoons. To increase the number of vehicles in the platoon and reduce the power consumption, we propose a two-step resource allocation strategy in consideration of platoon formation, i.e., the resource allocation at the base station (BS) and within each platoon. A branch and bound algorithm is utilized for the resource allocation at the BS. We then design a distributed dynamic programming-based subchannel allocation and power control algorithm for the joint optimization of platoon formation, subchannel allocation, and power control. The simulation results evaluate the impact of the penalty factor and the latency requirement on the system performance. [ABSTRACT FROM AUTHOR]

Single-frequency network (SFN) can be applied to advanced television systems committee (ATSC) 3.0-based terrestrial broadcasting systems to improve the service availability and quality of service without additional spectral resources. The main problem of SFN planning is the co-channel interference caused by multiple transmitters that use the same radio frequency for signal transmission and reception. The effect of the co-channel interference can be minimized by adjusting the network delay and transmit power of multiple transmitters within the SFN coverage area. To adjust the delay and power, it is necessary to estimate the channel impulse response (CIR) from each transmitter to a receiver. To support this process, a transmitter identification (TxID) signal is embedded in an original ATSC 3.0 signal. At the receiver, the individual CIR may be measured by a correlation-process-based TxID detection. However, since the correlation process may require large computational efforts, it is a quite challenging work to design a TxID detection algorithm with reduced complexity. This paper proposes a low-complexity TxID detection algorithm. The design and performance of the proposed algorithm is investigated and analyzed through numerical simulations. The simulation results indicate that the proposed algorithm can offer almost the same performance as the conventional TxID detection algorithm with significantly reduced complexity. [ABSTRACT FROM AUTHOR]

In this paper, a novel demapper for 2-D non-uniform constellations (2D-NUCs) is proposed, exploiting the characteristics of these constellations. It represents the combination of two underlying demapping techniques targeting the ATSC 3.0 compliant OFDM transceiver. On the one hand, for low code rates, we define a metric to perform condensed demapping. On the other hand, for high code rates, adaptive sub-region demapping is proposed. In this paper, a combination of both demapping methods is designed showing comparable performance to the classical ML demapper. The gap does not exceed 0.1 dB for all code rates of the ATSC 3.0 standard. Higher complexity reduction, from 79.2% to 95.4%, than state of art 2D-NUC demappers is obtained for 2D-256NUCs. These results are validated for ideal and non-ideal channel state information over additive white noise Gaussian and Rayleigh independently and identically distributed channels. Results are extended to 2D-1kNUCs and 2D-4kNUCs showing demapping complexity reduction from 96% to 99.7% with a negligible impact on performance. [ABSTRACT FROM AUTHOR]

We study the problem of maximizing the broadcast rate in peer-to-peer (P2P) systems under node degree bounds, i.e., the number of neighbors a node can simultaneously connect to is upper-bounded. The problem is critical for supporting high-quality video streaming in P2P systems and is challenging due to its combinatorial nature. In this paper, we address this problem by providing the first distributed solution that achieves near-optimal broadcast rate under arbitrary node degree bounds and over arbitrary overlay graph. It runs on individual nodes and utilizes only the measurement from their one-hop neighbors, making the solution easy to implement and adaptable to peer churn and network dynamics. Our solution consists of two distributed algorithms proposed in this paper that can be of independent interests: a network-coding-based broadcasting algorithm that optimizes the broadcast rate given a topology, and a Markov-chain guided topology hopping algorithm that optimizes the topology. Our distributed broadcasting algorithm achieves the optimal broadcast rate over arbitrary P2P topology, while previously proposed distributed algorithms obtain optimality only for P2P complete graphs. We prove the optimality of our solution and its convergence to a neighborhood around the optimal equilibrium under noisy measurements or without time-scale separation assumptions. We demonstrate the effectiveness of our solution in simulations using uplink bandwidth statistics of Internet hosts. [ABSTRACT FROM AUTHOR]

Coded caching is an emerging technique to reduce the data transmission load during the peak-traffic times. In such a scheme, each file in the data center or library is divided into a number of packets to pursue a low broadcasting rate based on the designed placements at each user’s cache. However, the implementation complexity of this scheme increases with the number of packets. It is crucial to design a scheme with a small subpacketization level, while maintaining a relatively low transmission rate. Recently, a combinatorial structure called placement delivery array (PDA) was proposed as an effective tool to design coded caching schemes with a relatively low subpacketization level. This paper proposes a novel PDA construction by selecting proper orthogonal arrays (POAs), which generalizes the existing construction but with a more flexible memory size. Based on the proposed PDA construction, an effective transform is further proposed to enable a coded caching scheme to achieve a smaller subpacketization level. Moreover, two new coded caching schemes with the coded placement are derived. It is shown that the proposed schemes can yield a lower subpacketization level or transmission rate over the benchmark schemes. [ABSTRACT FROM AUTHOR]

We study an important specialization of the general problem of broadcasting on directed acyclic graphs, namely, that of broadcasting on two-dimensional (2D) regular grids. Consider an infinite directed acyclic graph with the form of a 2D regular grid, which has a single source vertex $X$ at layer 0, and $k + 1$ vertices at layer $k \geq 1$ , which are at a distance of $k$ from $X$. Every vertex of the 2D regular grid has outdegree 2, the vertices at the boundary have indegree 1, and all other non-source vertices have indegree 2. At time 0, $X$ is given a uniform random bit. At time $k \geq 1$ , each vertex in layer $k$ receives transmitted bits from its parents in layer $k-1$ , where the bits pass through independent binary symmetric channels with common crossover probability $\delta \in \left({0,\frac {1}{2}}\right)$ during the process of transmission. Then, each vertex at layer $k$ with indegree 2 combines its two input bits using a common deterministic Boolean processing function to produce a single output bit at the vertex. The objective is to recover $X$ with probability of error better than $\frac {1}{2}$ from all vertices at layer $k$ as $k \rightarrow \infty $. Besides their natural interpretation in the context of communication networks, such broadcasting processes can be construed as one-dimensional (1D) probabilistic cellular automata, or discrete-time statistical mechanical spin-flip systems on 1D lattices, with boundary conditions that limit the number of sites at each time $k$ to $k+1$. Inspired by the literature surrounding the “positive rates conjecture” for 1D probabilistic cellular automata, we conjecture that it is impossible to propagate information in a 2D regular grid regardless of the noise level $\delta $ and the choice of common Boolean processing function. In this paper, we make considerable progress towards establishing this conjecture, and prove using ideas from percolation and coding theory that recovery of $X$ is impossible for any $\delta \in \left({0,\frac {1}{2}}\right)$ provided that all vertices with indegree 2 use either AND or XOR for their processing functions. Furthermore, we propose a detailed and general martingale-based approach that establishes the impossibility of recovering $X$ for any $\delta \in \left({0,\frac {1}{2}}\right)$ when all NAND processing functions are used if certain structured supermartingales can be rigorously constructed. We also provide strong numerical evidence for the existence of these supermartingales by computing several explicit examples for different values of $\delta $ via linear programming. [ABSTRACT FROM AUTHOR]

The use of Bluetooth Low Energy (BLE) beacons enhanced further for connectionless services such as location-specific information and navigation. With BLE 5.0, the way beacons deliver more information can move away from the current model of app-paired-to-device to a connectionless IoT. When users pass areas with installed BLE beacons, their mobile devices can receive specials, promotional contents, and discount coupons. However, the beacons are only broadcasting. This means that beacons are not able to collect information from the users with mobile devices. In this paper, we propose responsive advertising with the wait-slot scheme (RAWS) based on advertising extensions to improve the performance of the discovery process before further communications in BLE networks. Besides, we consider the energy consumption and investigate the latency-energy tradeoff with our proposed scheme. The theoretical lower bounds for both latency and energy of the discovery process as well as their tradeoff are presented. In addition, we formulate the state transition diagram for analyzing the performance of our proposed scheme. Simulation results validated by analysis results show that RAWS indeed improves the latency and the energy consumption of the discovery process in BLE networks. [ABSTRACT FROM AUTHOR]

The emerging 360-degree video has a good practical prospect in video broadcasting due to its more immersive experience than traditional videos. To maintain a high fidelity with panoramic vision, 360-degree video adopts a significantly increased resolution than planar videos, which also inevitably leads to higher encoding complexity. In this paper, we propose a flexible complexity optimization method for 360-degree video coding, in which the encoder is capable of adapting to different complexity constraints in diversified broadcasting scenarios. In particular, the proposed method is realized with a latitude-based computation complexity allocation. Firstly, it investigates the Coding Unit (CU) partition variation along the latitude (i.e., vertical axis) and divides each video frame into Largest CU (LCU)-based latitude regions. Then, it formulates the complexity allocation problem from the global complexity target to all latitude regions, by considering the intraframe dependencies and Rate-Distortion (RD) models. Finally, it calculates the solution to this complexity allocation problem and further employs it in 360-degree video coding. Comprehensive experiments on the standard dataset reveal the superiority of our method, which achieves a flexible computational time reduction from 14.53% to 68.36% whilst maintaining a high visual quality of compressed videos. [ABSTRACT FROM AUTHOR]

There emerges a strong trend recently to create an intelligent and controllable wireless transmission environment by installing reconfigurable intelligent surfaces (RIS) on the surface of diverse. We research the use of RIS in 5G multicast TV applications in this paper. In particular, the shape-adaptive RIS is developed to relay 5G multicast TV signals and achieve extra RIS gain. To optimize the shape bending in RIS model, we employ the algorithm of Deep Deterministic Policy Gradient (DDPG), a reinforcement learning technique that combines both Q-learning and Policy gradients. Our simulation results show that RIS can considerably enhance the SINR of worst users and improve the system’s overall Modulation and Coding Scheme (MCS) level for 5G mobile broadcasting services. [ABSTRACT FROM AUTHOR]

Future connected and autonomous vehicles (CAVs) will operate at different autonomous levels for decades. Therefore, we propose a novel prioritisation scheme according to the autonomous levels of CAVs, and a corresponding multiple access mechanism, to be named full-duplex prioritised scheduling (FDPS) protocol, to enhance the delivery of high-priority packets in future New Radio (NR) enhanced vehicle-to-everything communication (eV2X) vehicular ad hoc networks (VANETs). Comparing to the standardised sensing-based semi-persistent scheduling (SB-SPS) protocol, this paper presents how collision detection is enabled during the broadcast, how collisions are resolved, how the priority of a packet from a colliding CAV is recognised, and how the broadcast of high-priority packets is enhanced. Both protocols are evaluated through mathematical formulations and simulations in terms of average successful packet delivery rate (PDR), collision duration, and latency. Simulation results have firstly validated the mathematical analysis, they have also shown the enhancement of packets delivery in future NR eV2X VANETs when the self-interference suppression (SIS) factor is better than 16%, which is achievable by deploying the existing SIS technologies. [ABSTRACT FROM AUTHOR]

In this paper, distributed spatial modulation (DSM) is introduced. DSM is a cooperative diversity protocol for multirelay wireless networks, which is based on the concept of spatial modulation (SM). The distinguishable feature of DSM lies in improving the reliability of the source via distributed diversity and by increasing the aggregate throughput of the network since new data is transmitted during each transmission phase. This is achieved by encoding the data transmitted from the source into the spatial positions of the available relays and by exploiting the signal domain to transmit the data of the relays. At the destination, a diversity combiner that is robust to demodulation errors at the relays is proposed, and its end-to-end error probability and achievable diversity are studied. It is mathematically proved that DSM allows the source to achieve second-order diversity. With the aid of Monte Carlo simulations, DSM is compared against state-of-the-art cooperative protocols, and it is shown to provide a better error probability. [ABSTRACT FROM AUTHOR]