D2D Communication Scheme Research Articles

MIMO Device-to-Device Communications via Cooperative Dual-Polarized Intelligent Surfaces

By making the propagation environment a programmable entity, reconfigurable intelligent surfaces (RIS) constitute a key enabler to fulfill the quality-of-service requirements of device-to-device (D2D) communications. In practice, however, a single RIS may not be able to establish a line-of-sight path between the devices, e.g., in environments with rich scattering or when devices are far apart. This can hinder the communications especially in applications that require the transfer of different data sets from a source to multiple destinations. Considering such type of applications, this letter proposes a dual-polarized cooperative RIS-assisted MIMO D2D communication scheme, where the beam routing path via multiple RISs is selected based on the maximum received signal-to-noise ratio and path constraints. Looking into system operation in indoor environments, and utilizing a realistic channel model, tractable expressions are obtained for the system’s error rate and outage probability. An asymptotic analysis is also conducted to evaluate the diversity gain. The findings reveal significant advantages of the dual-polarized cooperative RIS scheme over other RIS-based schemes.

Reinforcement-Learning-Based Spatial Resource Identification for IoT D2D Communications

The exponential growth of the Internet of Things (IoTs) has led to an increasing demand for intelligent IoT devices (IoTDs), requiring innovative network capacity expansion. Recently, several research has been conducted on the identification of hidden network resources for network capacity expansion. However, the spatial resource identification scheme through the omnidirectional antenna has limitations in terms of frequency efficiency compared to the scheme with the directional antenna. In this article, we propose a directional spatial-resource identification technique for device-to-device (D2D) communication. To find the optimal identification parameters, we design the objective function and apply a reinforcement learning. The training data used for reinforcement learning are collected in each report phase, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$Q$</tex-math></inline-formula> -learning is applied to find the optimal beam set. Furthermore, based on the obtained frequency information, we propose a contention-based D2D communication scheme. The proposed contention-based D2D communication scheme can efficiently solve the deafness problem occurring in a directional D2D communication. Finally, we perform a simulation using optimum network performance (OPNET) to measure the performance and evaluate the effectiveness of the proposed technique. The simulation results show that the proposed schemes realize a better performance than the existing schemes proposed in previous works in terms of energy efficiency, frequency efficiency, aggregate network throughput, and deafness duration.

Gamified Participatory D2D Communication for Encouraging User Participation Toward Future Mobile Communication

Device-to-Device (D2D) communication is a promising solution in next generation cellular technologies to efficiently provide on-demand connectivity. Among existing D2D communication schemes, the outband approach that uses unlicensed spectrum can eliminate the spectrum interference with cellular links. Although the autonomous outband is a strong option because of its simple operation, it is a significant problem to appropriately encourage the participation of mobile users. To address this issue, this paper proposes a gamified participatory D2D (GP-D2D) communication where mobile users compete their gain that is obtained through providing network connectivity for other mobile users. The contribution of this work is to propose a novel approach of the autonomous outband D2D communication for efficiently encouraging the active participation of mobile users. The feasibility of the proposed gamified approach is confirmed with theoretical analysis and computer simulations. It is implied from the results that gamification is an effective approach for autonomous D2D communication by defining appropriate game-settings such as gain mechanisms.

Energy-efficient resource allocation for heterogeneous network with grouping D2D

In this paper, a new communication model is built named grouping D2D (GD2D). Different from the traditional D2D coordination, we proposed GD2D communication in licensed and unlicensed spectrum simultaneously. We formulate a resource allocation problem, which aims at maximizing the energy efficiency (EE) of the system while guaranteeing the quality-of-service (Qos) of users. To efficiently solve this problem, the non-convex optimization problem is first transformed into a convex optimization problem. By transforming the fractional-form problem into an equivalent subtractive-form problem, an iterative power allocation algorithm is proposed to maximize the system EE. Moreover, the optimal closed- form power allocation expressions are derived by the Lagrangian approach. Simulation results show that our algorithm achieves higher EE performance than the traditional D2D communication scheme.

DIYA: Tactile Internet Driven Delay Assessment NOMA-Based Scheme for D2D Communication

Device-to-device (D2D) two-hop cooperative communication improves the network coverage and throughput to provide the quality of service and quality of experience to the end users. Nonorthogonal multiple access (NOMA) can be used at the D2D transmitter to improve the spectral efficiency of the network. But, two-hop transmission with NOMA suffers from delay and interference from the neighboring nodes. To resolve the aforementioned issues, in this paper, we propose Tactile Internet (TI) driven delay assessment for D2D communication (DIYA) scheme, which works in two phases. In the first phase, a full duplex communication at relays (intermediate nodes) is used to have the first- and second-hop transmission simultaneously in the same time slot. Then, TI-based communication is used at D2D transmitter to increase the speed of transmission. In the second phase, pricing-based three-dimensional (3-D) matching is proposed to improve the throughput of the cell edge users along with the mitigation of cochannel interference. Also, the power of the D2D transmitter is optimized using successive convex approximation with low complexity, which converts the nonconvex optimization problem of subchannel allocation and power control into convex problem. Numerical results demonstrate that DIYA achieves higher throughput with reduced delay in comparison to other existing orthogonal multiple access (OMA) and NOMA-based schemes.

A New Cooperative Dual-Level Game Approach for Operator-Controlled Multihop D2D Communications

With the development of wireless communications and the intellectualization of mobile devices, device-to-device (D2D) communications are considered as a standard part of future 5G networks. This new paradigm can provide better user experiences while improving the system performance such as network throughput, latency, fairness, and energy efficiency. In this study, we investigate a new dual-level D2D communication scheme consisting of multiple D2D operators and a group of mobile devices. To model the interaction among D2D operators and devices, we adopt two cooperative game approaches based on the incentive mechanism design and r-egalitarian Shapley value. At the upper level, routing paths and incentive payments for multihop relay services are decided using the incentive mechanism. At the lower level, mobile devices share the given incentive based on the r-egalitarian Shapley value. Both level control procedures are mutually dependent on each other by the proper coordination and collaboration. According to the main features of two cooperative game models, the proposed scheme takes various benefits in a fair-efficient way. Through the derived simulation results, we can verify the superiority of our proposed scheme comparing to the existing protocols. Finally, we propose further challenges and future opportunities in the research area of operator-controlled multihop D2D communications.

Relay-Assisted D2D Transmission for Mobile Health Applications.

Relay-assisted Device-to-Device (D2D) communication, one of the important transmission modes in mobile health systems, can provide high transmission quality for servicing users at the edge of system coverage. However, the quality of the D2D relay communication is largely limited by the relay nodes. When a poor node is selected to assist the source node in the data transmission, it is likely to result in the loss of medical data and inaccurate transmission. Therefore, this paper focuses on how to select relay modes and relay nodes to improve the reliability of medical data transmission. Firstly, in order to eliminate the relay nodes with low energy or poor willingness, the acceptable energy consumption metric of relay nodes is proposed in this paper. The relay mode of each relay node is determined by the acceptable energy consumption metric, which can ensure the physical reliability of the relay communication links. Then a trust metric is proposed to measure the social reliability of each relay link, further excluding the malicious relay nodes. Finally, this paper proposes a relay selection algorithm based on compromise factors (RSCF). With the help of the proposed algorithm, the reliability of the relay communication can be guaranteed, and the spectrum efficiency can be promoted greatly. The simulation results show that the relay nodes selected by RSCF algorithm can greatly improve transmission rate and reliability compared with the traditional relay-assisted D2D communication schemes.

Mode selection schemes for unicasting device‐to‐device communications supported by network coding

SummaryDevice‐to‐device (D2D) communication in a cellular spectrum increases the spectral and energy efficiency of local communication sessions, while also taking advantage of accessing licensed spectrum and higher transmit power levels than when using unlicensed bands. To realize the potential benefits of D2D communications, appropriate mode selection algorithms that select between the cellular and D2D communication modes must be designed. On the other hand, physical‐layer network coding (NWC) at a cellular base station—which can be used without D2D capability—can also improve the spectral efficiency of a cellular network that carries local traffic. In this paper, we ask whether cellular networks should support D2D communications, physical‐layer NWC, or both. To this end, we study the performance of mode selection algorithms that can be used in cellular networks that use physical‐layer NWC and support D2D communications. We find that the joint application of D2D communication and NWC scheme yields additional gains compared with a network that implements only one of these schemes, provided that the network implements proper mode selection and resource allocation algorithms. We propose 2 mode selection schemes that aim to achieve high signal‐to‐interference‐plus‐noise ratio and spectral efficiency, respectively, and take into account the NWC and D2D capabilities of the network.

An intra–inter-cell device-to-device communication scheme to enhance 5G network throughput with delay modeling

As the number of mobile users is growing, so is the demand for more bandwidth. It becomes important that the required bandwidth and spectral resources do not scale with traffic in the next generation of wireless networks [i.e. fifth generation (5G)]. Device-to-device (D2D) communication underlaying cellular networks has been recognized as an essential technique in 5G networks. By applying definite principles and strategies, D2D communication not only increases the spectral and energy efficiency, but also enhances network throughput, network coverage and reduces delay. In this paper, we present an intra–inter-cell D2D communication scheme to enhance throughput of 5G networks. We study call setup delay of two developed communication scenarios and throughput gain comparing three systems. Firstly, we show the enhancements required in current cellular architectures to support inter-cell D2D communication. We develop protocols for two scenarios and demonstrate how architecture entities cooperate for the call setup between D2D users. We measure the overall call setup time for the developed protocols and derive a closed-form delay formula to estimate call setup time probability. Secondly, we perform simulations using a topology similar to that found in realistic urban environments to study throughput gains of the proposed intra–inter-cell D2D communication scheme. We compare three systems in terms of throughput: (1) pure cellular system (with cellular users only), (2) pure cellular system with intra-cell D2D users sharing the same cellular resource, and (3) pure cellular system with intra–inter-cell D2D users sharing the same cellular resource. Simulation results show that the proposed scheme substantially increases the network throughput and spectrum efficiency.

Power Control for Device-to-Device Communication with a Hybrid Relay Mode in Unequal Transmission Slots

Device-to-device (D2D) pairs are allowed to reuse the spectrum of cellular users who are in a good quality channel state with underlaying cellular network. However, cellular users usually suffer a poor performance in term of achievable rate when they are in a cell edge or in deep fading. To solve this problem, a hybrid relay-aided D2D communication scheme with a two-antenna infrastructure and using two unequal transmission slots is proposed in this paper. Different from the pure half-duplex and full-duplex D2D relay work, the hybrid-duplex relay mode that we propose enables the D2D relay to receive and transmit signals at the same time in the first time slot. Thus, it is similar to the full-duplex which could increase the spectrum efficiency. In addition, in the second time slot, the D2D relay will forward only the cellular user’s signals, thus avoiding the transmission of mixed signals which would deteriorate the system performance, similarly to the half-duplex mode. Moreover, by bringing in a slot splitting factor, the relay node in our hybrid-duplex mode is set to guarantee the matching of the transmission rate in two hops. We formulate the problem of maximizing the D2D transmission rate while guaranteeing in priority the minimum rate for the cellular user. By using the method of rate matching and linear programming, we deduce the expression of the slot splitting factor as well as the optimal power allocation for the base station and D2D relay, while guaranteeing the minimum rate requirement for the cellular user in a close form. The simulation results show that the proposed relay-based hybrid-duplex D2D scheme outperforms the existing half-duplex and full-duplex relay-based D2D communication schemes in term of achievable rate.

Power Allocation for Maximizing Uplink Rate Over Full-Duplex Relay-Based D2D Communication Underlying Cellular Networks

Device-to-device (D2D) communications, which can increase system throughput, allow two cellular devices to communicate directly with each other. Compared with half-duplex relay, full-duplex relay can significantly improve the spectrum efficiency if the self-interference can be efficiently eliminated. This paper proposes a D2D communication scheme, which assigns the fixed D2D transmitter as full-duplex amplify-and-forward relay to assist cellular uplink transmission. Cellular user close to the fixed D2D transmitter can directly download the video by D2D communications. An optimization problem is formulated to maximize the uplink rate of cellular user while guaranteeing the rate requirement of D2D user. We first obtain the feasible region of the power splitting factor, which characterizes the proportion of fixed D2D transmitter power allocated to cellular uplink and D2D communications. Then, a closed-form expression of the optimal power allocation scheme is derived. Also simulation results are presented to validate the proposed optimal power allocation scheme for uplink rate maximization.

A Novel D2D Communication Scheme for Location-Based OTT Service in Cellular Networks

A Novel D2D Communication Scheme for Location-Based OTT Service in Cellular Networks

Cooperative Game-based Cheating in Full-duplex Relaying-based D2D Communication Underlaying Heterogeneous Cellular Networks

Device-to-device (D2D) communications allow direct transmissions between two adjacent user devices, which can improve system performance in cellular networks. Considering full-duplex (FD) relaying outperforms half-duplex (HD) relaying in spectrum and energy efficiency, we apply the FD relaying-based D2D communication scheme in heterogeneous cellular network, which allows D2D links to underlay cellular downlink by assigning D2D transmitters as FD relays to assist cellular downlink transmissions. Although the scheme can improve the utilization of spectrum resource dramatically, the unreasonable resource sharing of D2D users will increase the inter-user interference. Therefore, in this paper, we try to optimize the throughput of D2D users on the premise of ensuring the quality of service (QoS) of cellular users. To this end, we first propose a D2D transmit power-allocation scheme and use Gale-Sharpley (GS) algorithm in matching theory to solve the resource allocation problem. Next, a Cheating algorithm based on cooperative game theory is proposed to further improve the throughput of D2D users. More importantly, due to the NP-hardness of finding the optimal solution of Cheating algorithm, we propose a heuristic algorithm based on depth first search (DFS) which using different colors to represent the different statements of D2D users to find a near-optimal solution. The simulation results show that the proposed algorithm compared with GS algorithm can significantly improve the total throughput of D2D users, and it also has lower complexity and better throughput performance against existing Cheating algorithm.

Joint Subchannel and Power Allocation for NOMA Enhanced D2D Communications

In this paper, a novel non-orthogonal multiple access (NOMA) enhanced device-to-device (D2D) communication scheme is considered. Our objective is to maximize the system sum rate by optimizing subchannel and power allocation. We propose a novel solution that jointly assigns subchannels to D2D groups and allocates power to receivers in each D2D group. For the subchannel assignment, a novel algorithm based on the many-to-one two-sided matching theory is proposed for obtaining a suboptimal solution. Since the power allocation problem is non-convex, sequential convex programming is adopted to transform the original power allocation problem to a convex one. The power allocation vector is obtained by iteratively tightening the lower bound of the original power allocation problem until convergence. Numerical results illustrate that: 1) the proposed joint subchannel and power allocation algorithm are an effective approach for obtaining near-optimal performance with acceptable complexity and 2) the NOMA enhanced D2D communication scheme is capable of achieving promising gains in terms of network sum rate and the number of accessed users, compared to a traditional OMA-based D2D communication scheme.

DORE: An Experimental Framework to Enable Outband D2D Relay in Cellular Networks

Device-to-Device (D2D) communications represent a paradigm shift in cellular networks. In particular, analytical results on D2D performance for offloading and relay are very promising, but no experimental evidence validates these results to date. This paper is the first to provide an experimental analysis of outband D2D relay schemes. Moreover, we design D2D opportunistic relay with QoS enforcement (DORE), a complete framework for handling channel opportunities offered by outband D2D relay nodes. DORE consists of resource allocation optimization tools and protocols suitable to integrate QoS-aware opportunistic D2D communications within the architecture of 3GPP Proximity-based Services . We implement DORE using an SDR framework to profile cellular network dynamics in the presence of opportunistic outband D2D communication schemes. Our experiments reveal that outband D2D communications are suitable for relaying in a large variety of delay-sensitive cellular applications, and that DORE enables notable gains even with a few active D2D relay nodes.

Secure beamforming design for SWIPT in cooperative D2D communications

In device-to-device (D2D) communications, device terminal relaying makes it possible for devices in a network to function as transmission relays for each other to enhance the spectral efficiency. In this paper we consider a cooperative D2D communication system with simultaneous wireless information and power transfer (SWIPT). The cooperative D2D communication scheme allows two nearby devices to communicate with each other in the licensed cellular bandwidth by assigning D2D transmitters as half-duplex (HD) relay to assists cellular downlink transmissions. In particular, we focus on secure information transmission for the cellular users when the idle D2D users are the potential eavesdroppers. We aim to design secure beamforming schemes to maximize the D2D users data rate while guaranteeing the secrecy rate requirements of the cellular users and the minimum required amounts of power transferred to the idle D2D users. To solve this non-convex problem, a semi-definite programming relaxation (SDR) approach is adopted to obtain the optimal solution. Furthermore, we propose two suboptimal secure beamforming schemes with low computational complexity for providing secure communication and efficient energy transfer. Simulation results demonstrate the superiority of our proposed scheme.

Social-aware energy harvesting device-to-device communications in 5G networks

With ever increasing demands for local area services in 5G cellular networks, solutions are necessary to deliver local area data in a spectrum- and energy-efficient manner. In this article we propose a new cellular communication architecture that integrates energy harvesting technologies and social networking characteristics into D2D communications for local data dissemination. The proposed architecture includes three domains: the physical domain, the energy domain, and the social domain. Specifically, in the physical domain, D2D communications enable two nearby users to communicate with each other directly. In the energy domain, devices harvest energy from renewable energy sources. In the social domain, D2D users form social networks exhibiting stable social structures and relations. Then we mainly focus on the efficient local data dissemination issues in the proposed architecture and propose two social-aware energy harvesting D2D communication schemes (device relay and device multicast). Illustrative results demonstrate significant spectrum and energy efficiency enhancement for local data dissemination in 5G cellular networks.

Caching based socially-aware D2D communications in wireless content delivery networks: a hypergraph framework

The emergence of the D2D communications paradigm has transformed the way in which cellular networks are operated. Previous work in D2D communications, however, mainly focused on interference management and capacity maximization of both D2D links and cellular links. Recent literature has observed that the QoE can be greatly enhanced by caching contents in mobile devices, with a carefully designed caching strategy. In this article, we propose a novel hypergraph framework that designs the caching based D2D communication scheme by taking social ties among users and common interests into consideration. We first present the considered features of the D2D transmission scheme, social characteristics consideration, and interest similarity impact. The key concepts of hypergraph and related techniques, such as hypergraph coloring and multidimensional matching, are explained. Then some design issues with simulation results in the proposed framework are discussed in detail, which show the potential of the proposed approach. By jointly considering social ties, common interests, and the D2D transmission scheme, we believe the proposed framework explores new opportunities and future directions in caching based socially-aware D2D communications.

Socially aware cluster formation and radio resource allocation in D2D networks

Due to the popularity of mobile user devices, D2D communications become a key technology to improve local services in the next generation cellular networks. However, the benefits count on efficient radio resource allocation between cellular links and D2D links, which poses critical challenges. By exploiting the network knowledge extracted from underlying mobile social networks (MSNs), this article proposes a socially aware D2D communication scheme to improve the spectrum and energy efficiency in cellular networks. First, by jointly considering the social and network knowledge, we propose a cluster formation scheme to categorize a group of UEs into multiple D2D clusters. Within each cluster, highly spectrum-efficient D2D multicasting (from the cluster head, i.e., a D2D transmitter UE to multiple cluster member UEs) is enabled. Next, a half-duplex scheme and a full-duplex scheme are proposed to coordinate the channel sharing between the cellular links and the D2D links. Simulation results show that the proposed schemes can form D2D clusters rationally among a group of UEs, and therefore largely increase the spectrum and energy efficiency of the network.

Power Allocation for Full-Duplex Relaying-Based D2D Communication Underlaying Cellular Networks

Device-to-device (D2D) communications allow direct transmissions between two proximate user equipments (UEs), which can improve local services in cellular networks. Considering full-duplex (FD) relaying can achieve higher spectrum and energy efficiency than half-duplex (HD) relaying, we propose a new D2D communication scheme that allows D2D links to underlay cellular downlink by assigning D2D transmitters as FD relays to assist cellular downlink transmissions. The system objective is to optimize the achievable rates for the D2D users while fulfilling the minimum rate requirements of the cellular users. To this end, we first derive the achievable rates for both the D2D users and the cellular users. Then we accomplish the system target by optimizing the transmission powers at the base station (BS) and at the D2D transmitter. Under the aggregate power constraint, we can solve the optimal power-allocation problem in closed form. The simulation results show that the proposed FD relaying-based D2D communication scheme outperforms the traditional cellular communication mode and the existing HD relaying-based D2D communication scheme in the maximal achievable rate.