D2D Mode Research Articles

Resource allocation, interference management, and mode selection in device‐to‐device communication: A survey

AbstractFor us to meet the demands of fifth generation technologies, device‐to‐device (D2D) communication is foreseen to be an important part of fifth generation networks. Device‐to‐device communication brings significant improvement in user's throughput, battery life, communication delay, and resource usage. Device‐to‐device links share the same resource with the cellular links that results in interference between cellular users and D2D user equipments. This interference can be managed by suitable resource allocation algorithms. The selection of D2D or cellular communication mode is also a hot research issue. Many research works are available in literature on the aforementioned issues regarding D2D communication, but there is no survey available in the literature. To facilitate the researchers, we present a detailed and systematic survey on resource allocation, interference management, and mode selection in D2D communication in this paper. Initially, the taxonomy based overview of D2D communication is provided, and the classification of the works is outlined. Then, the works regarding mode selection are reviewed in detail. Furthermore, interference management schemes to handle the interference caused by the underlying nature are also surveyed. Then, the available literature on resource allocation schemes in D2D perspective are presented. Finally, some open research problems are identified that deserve further research.

Joint Mode Selection and Interference Management in Device-to-Device Communications Underlaid MIMO Cellular Networks

This paper considers a device-to-device (D2D) communications underlaid multiple-input multiple-output cellular network and studies D2D mode selection from a previously unexamined perspective. Since D2D mode selection affects the network interference profile and vice versa, a joint D2D mode selection and interference management is desired but challenging. In this paper, we propose a holistic approach to this problem with interference-free considerations. We adopt the degrees-of-freedom (DoFs) as the mode-selection criterion and exploit the linear interference alignment technique for interference management. We analyze the achievable sum DoF of the potential D2D users according to their mode selections, and derive the probabilistic sum-rate relations between the proposed DoF-based mode selection scheme and the common received-signal-strength-index-based mode selection scheme in Poisson point process networks. Simulation illustrates the theoretical insights and shows the advantages of the proposed DoF-based mode selection scheme over conventional mode selection schemes from various perspectives. The proposed scheme presents a promising proposal for D2D mode selection in 5G communications.

Device-to-Device Communication Underlaying a Finite Cellular Network Region

Underlay in-band device-to-device (D2D) communication can improve the spectrum efficiency of cellular networks. However, the coexistence of D2D and cellular users causes inter-cell and intra-cell interference. The former can be effectively managed through inter-cell interference coordination and, therefore, is not considered in this work. Instead, we focus on the intra-cell interference and propose a D2D mode selection scheme to manage it inside a finite cellular network region. The potential D2D users are controlled by the base station (BS) to operate in D2D mode based on the average interference generated to the BS. Using stochastic geometry, we study the outage probability experienced at the BS and a D2D receiver, and spectrum reuse ratio, which quantifies the average fraction of successfully transmitting D2D users. The analysis shows that the outage probability at the D2D receiver varies for different locations. Additionally, without impairing the performance at the BS, if the path-loss exponent on the cellular link is slightly lower than that on the D2D link, the spectrum reuse ratio can have negligible decrease while the D2D users' average number of successful transmissions increases with increasing D2D node density. This indicates that an increasing level of D2D communication can be beneficial in future networks..

Joint Opportunistic Scheduling of Cellular and Device-to-Device Communications

The joint scheduling of cellular and D2D communications to share the same radio resource is a complex task. In one hand, D2D links provide very high throughputs. In the other hand, the intra-cell interference they cause impacts on the performance of cellular communications. Therefore, designing algorithms and mechanisms that allow an efficient reuse of resources by the D2D links with a reduced impact on cellular communications is a key problem. In general, traditional Radio Resource Management (RRM) schemes (D2D grouping and mode selection) focus on finding the most compatible D2D pair for an already scheduled cellular User Equipment (UE). However, such approach limits the number of possible combinations to form the group (composed by a cellular UE and a D2D pair) to be scheduled in the radio resource. To overcome that, in this work a unified Joint Opportunistic Scheduling (JOS) of cellular and D2D communications, which is able to improve the total system throughput by exploiting the spatial compatibility among cellular and D2D UEs, is proposed. But more complexity is brought to the scheduling problem. Thus, a low-complexity suboptimal heuristic Joint Opportunistic Assignment and Scheduling (JOAS) is also elaborated. Results show that it is possible to reduce the computational complexity but still improve the overall performance in terms of cellular fairness and total system throughput with less impact on cellular communications.

QoS-Oriented Mode, Spectrum, and Power Allocation for D2D Communication Underlaying LTE-A Network

This paper investigates the problem of resource allocation for device-to-device (D2D) communication in a Third-Generation Partnership Project (3GPP) Long-Term Evolution Advanced (LTE-A) network. The users in the network can operate either in a traditional cellular mode, communicating with each other via the evolved NodeB (eNB), or in a D2D mode, communicating with each other without traversing the eNB. In the considered model, the D2D users and cellular users share the same radio resources. Particularly, each resource block (RB) within the available bandwidth can be occupied by one cellular and several D2D users. Hence, the problem of interference management is crucial for effective performance of such a network. The twofold aim of the proposed algorithm is to 1) mitigate the interference between cellular and D2D users and 2) improve the overall user-perceived quality of service (QoS). To control the interference, for each user, we define a certain target interference level and constrain the interference from the other users to stay below this level. The corresponding optimization problem maximizes the QoS of the users by minimizing the size of the buffers of user equipments (UEs). The performance of the algorithm has been evaluated by using the OPNET-based simulations. The algorithm shows improved performance in terms of mean packet end-to-end delay and loss for UEs when compared to other relevant schemes.

Coverage probability analysis for Full-Duplex relay aided Device-to-Device communications networks

The coverage probability of both the cellular users and the Device-to-Device (D2D) users are analyzed. We assume that the cellular users are able to communication with the Base Station (BS) either by relying on the assistance of Full-Duplex (FD) mode relays or via direct user-to-BS links with high-enough Signal-to-Interference-plus-Noise-Ratio (SINR). Note that the FD-mode devices are capable of simultaneously operating in two modes, i.e. the D2D mode and the cooperative relay mode, with the sum power consumption at these devices kept constant. The closed-form expressions for coverage probability of both tier users are derived. After that, numerical analyses are provided, showing that the coverage probability of the both the cellular and the D2D users can be substantially influenced by a variety of parameters, including the power allocation factor of the relays, the density of users, and the self-interference imposed on the FD mode relays, etc. Furthermore, in the D2D enabled networks, it is shown that the FD relay aided transmission is beneficial to enhancing the coverage probability of the cellular users if the target SINR is lower than 5 dB.

Analytical Modeling of Mode Selection for Moving D2D-Enabled Cellular Networks

Device-to-device (D2D) communications have been proposed as a promising technology to improve network capacity and user experiences. In this letter, we make theoretical analyses on D2D mode selection with user mobility. Using the stochastic geometry, we deduced that the D2D communication range can be well represented by biased circles with varying radius. Besides, a tractable analytical framework considering both absolute movement and relative movement for mode selection in moving D2D scenarios is presented. Under the proposed model, the closed-form expressions of D2D mode transition rate and D2D mode residence time are derived, which are the key parameters for moving D2D mode selection performance.

D2D Enhanced Co-Ordinated Multipoint in Cloud Radio Access Networks

Coordinated multipoint (CoMP) is an efficient technique to increase cell-edge coverage probability and throughput in cloud radio access network (C-RAN). In this paper, we integrate device-to-device (D2D) communications with CoMP by applying a distance based mode selection rule for downlink users in C-RAN, exploiting the proximity of D2D communications to improve system spectral efficiency. Using stochastic geometry, we first derive the signal-to-interference ratio distribution at a typical downlink user and a typical D2D receiver when two types of CoMP schemes, namely, zero-forcing beamforming (ZFBF) and noncoherent joint transmission (NC-JT), are applied in C-RAN. In addition, we analytically compare ZFBF and NC-JT using rate coverage probability. Meanwhile, we analyze the effect of D2D communications on enhancing the area spectral efficiency (ASE) of CoMP enabled C-RAN system. Numerical results show that increasing the co-operative cluster size would potentially degrade the system ASE when the network is heavily loaded. Furthermore, it is observed that enabling D2D mode in C-RAN can effectively offload the traffic of C-RAN and provide significant ASE gains if mode selection threshold is properly designed. Lastly, it is analytically demonstrated that spectrum resources can be better exploited by D2D users if they coexist with ZFBF enabled radio units (RUs) rather than NC-JT enabled RUs.

Mode Selection, Resource Allocation, and Power Control for D2D-Enabled Two-Tier Cellular Network

This paper proposes a centralized decision making framework at the macro base station (MBS) for device to device (D2D) communication underlaying a two-tier cellular network. We consider a D2D pair in the presence of an MBS and a femto access point, each serving a user, with quality of service constraints for all users. Our proposed solution encompasses mode selection (choosing between cellular or reuse or dedicated mode), resource allocation (in cellular and dedicated mode) and power control (in reuse mode) within a single framework. The framework prioritizes D2D dedicated mode if the D2D pair are close to each other and orthogonal resources are available. Otherwise, it allows D2D reuse mode if the D2D satisfies both the maximum distance and an additional interference criteria. For reuse mode, we present a geometric vertex search approach to solve the power allocation problem. We analytically prove the validity of this approach and show that it achieves near optimal performance. For cellular and dedicated modes, we show that frequency sharing maximizes sum rate and solve the resource allocation problem in closed form. Our simulations demonstrate the advantages of the proposed framework in terms of the performance gains achieved in D2D mode.

Mode Selection for Energy Efficient Content Delivery in Cellular Networks

Device-to-device (D2D) content delivery may improve resource efficiency for future content-centric cellular network due to the character of proximal transmission. However, when to use D2D technique can bring this performance improvement is still not clear. This letter investigates factors impacting on content delivery and proposes a criteria for delivery mode (cellular mode and D2D mode) selection. With this criteria, a more energy efficient delivery mode can be selected adaptively according to transmitter deployment, delivery coverage, channel quality, and quality-of-service (QoS) requirement. Simulation results show that compared with random mode selection scheme, the proposed mode selection strategy can reduce energy consumption for successful content delivery under different cases (e.g., up to 50% energy reduction for a successful content delivery). In addition, results on relationships among influencing factors and delivery efficiency match our theoretical analysis.

Adaptive Mode Selection in D2D Communications Considering the Bursty Traffic Model

This letter proposes a new mode selection scheme to improve the overall packet rates for device-to-device (D2D) communications systems in the bursty traffic model. We consider three types of D2D modes, i.e., dedicated mode, cellular mode, and reuse mode. In the full-buffer traffic model, if all the uplink (UL) channels are occupied by cellular users, the dedicated and cellular modes are not available for D2D user equipments (DUEs) to choose. However, in bursty traffic model, the traffic load is time-varying and DUEs have the option to select the dedicated or cellular modes. To determine the best mode for a DUE in the bursty traffic, we propose a mode selection scheme, which considers the traffic load for the bursty traffic model. Numerical results show that the proposed scheme achieves a remarkable enhancement in average end-to-end delay, dropping probability, and packet rate.

Optimal Mode Selection in D2D-Enabled Multibase Station Systems

In this letter, we consider device-to-device (D2D) communication underlaying uplink cellular networks with multiple base stations (BSs), where each user can switch between traditional cellular mode (through BS) and D2D mode (by connecting proximity user), namely mode selection. We impose load balancing constraints on BSs to efficient resource usage. The joint problem of mode selection and user association is formulated as a combinatorial problem and NP-complete. We adopt a graph-based approach to solve the problem globally optimally in polynomial time. To further reduce complexity, we also propose a distributed algorithm based on dual method. We show that the proposed distributed algorithm achieves nearly the same performance as the proposed optimal graph-based algorithm.

Device-To-Device (D2D) Communication Under LTE-Advanced Networks

Device-to-Device (D2D) communication is a new technology that offer many advantages for the LTEadvanced network such us wireless peer-to-peer services and higher spectral efficiency. It is also considered as one of promising techniques for the 5G wireless communications system and used in so many different fields such as network traffic offloading, public safety, social services and applications such as gaming and military applications . The goal of this paper is to present advances on the current 3GPP LTE-advanced system related to Device-to-Device (D2D). In this paper, we provide an overview of the D2D types based on the communication spectrum of D2D transmission, namely Inband D2D communication and Outband D2D communication. Then we present the advantages and disadvantages of each D2D mode. Moreover, architecture and protocol enhancements for D2D communications under LTE-A network are described.

Resource allocation for network-controlled device-to-device communications in LTE-Advanced

Network-controlled device-to-device (D2D) communication allows cellular users to communicate directly, i.e., without passing through the eNodeB, while the latter retains control over resource allocation. This allows the same time---frequency resources to be allocated to spatially separated D2D flows simultaneously, thus increasing the cell throughput. This paper presents a framework for: (1) selecting which communications should use the D2D mode, and when, and (2) allocating resources to D2D and non-D2D users, exploiting reuse for the former. We show that the two problems, although apparently similar, should be kept separate and solved at different timescales in order to avoid problems, such as excessive packet loss. We model both as optimization problems, and propose a heuristic solution to the second, which must be solved at millisecond timescales. Simulation results show that our framework is practically viable, it avoids the problem of packet losses, increases throughput and reduces delays.

On the Outage Probability of Device-to-Device-Communication-Enabled Multichannel Cellular Networks: An RSS-Threshold-Based Perspective

In this paper, we study the outage probability of device-to-device (D2D)-communication-enabled cellular networks from a general threshold-based perspective. Specifically, a mobile user equipment (UE) transmits in D2D mode if the received signal strength (RSS) from the nearest base station (BS) is less than a specified threshold $\beta \ge 0$ ; otherwise, it connects to the nearest BS and transmits in cellular mode. The RSS-threshold-based setting is general in the sense that by varying $\beta$ from $\beta = 0$ to $\beta = \infty$ , the network accordingly evolves from a traditional cellular network (including only cellular mode) toward a wireless ad hoc network (including only D2D mode). We provide a unified framework to analyze the downlink outage probability in a multichannel environment with Rayleigh fading, where the spatial distributions of BSs and UEs are well explicitly accounted for by utilizing stochastic geometry. We derive closed-form expressions for the outage probability of a generic UE and that in both cellular mode and D2D mode and quantify the performance gains in outage probability that can be obtained by allowing such RSS-threshold-based D2D communications. We show that increasing the number of channels, although able to support more cellular UEs, may result in an increase of outage probability in the D2D-enabled cellular network. The corresponding condition and reason are also identified by applying our framework.

Mixed Mode Transmission and Resource Allocation for D2D Communication

In cellular communication systems with optional device-to-device (D2D) links, user equipments (UEs) can operate in either D2D mode or cellular mode for data transport. This work introduces mixed-mode D2D communication in which D2D links can operate in multiple modes through resource multiplexing. Within this framework, we study the problem of maximizing weighted D2D sum rate under cellular rate constraints by optimizing mixed-mode allocation and resource allocation in term of transmit power and subchannel assignment. Due to nonconvex cellular rate constraints and binary constraints of subchannel allocation, this problem is a nonconvex mixed-integer problem that is generally difficult to solve. We propose a two-step approach by introducing energy-splitting variables such that mixed-mode allocation and resource allocation can be decoupled and optimized independently. The resulting algorithm can be distributive, requires little signaling overhead, and has low computational complexity. We present extensive numerical results to demonstrate the practicality of our proposed algorithm with regard to various network parameters.

Combined Resource Allocation System for Device-to-Device Communication towards LTE Networks

The LTE networks are being developed to grant mobile broadband services in the fourth generation (4G) systems and allow operators to use spectrum more efficiently.D2D communication is a promising technique to provide wireless services and enhance spectrum exploitation in the LTE Heterogeneous Networks (HetNets).D2D communication in HetNets allows users to communicate with each other directly by reusing the resources when communicating via the base stations. But during the downlink period, both the D2D receiver and the Heterogeneous Users equipment’s (HUE) experience interference caused by resource allocation. In this article, we identify and analyze the interference problem of HetNets caused by D2D transmitter during download. We propose a combined resource allocation and resource reuse method for LTE HetNets, where resource allocation to HUEs is employed on the basis of comparative fair algorithm and resource reuse to D2D users is employed on acquisitive empirical algorithm. This approach evaluates whether D2D mode is suitable or not by path loss evaluation, after that decreases the interference to HUE by selection of the minimum channel gain between HUE and D2D transmitter each time to mitigate interference. Our simulation results show that the efficiency and throughput of HetNets is improved by using the proposed method.

Incentive mechanisms for device-to-device communications

D2D communication has recently been proposed as a promising technique to improve resource utilization of cellular networks by offloading the traffic through base stations to local direct links between devices. While various optimization frameworks have been intensively studied, little attention has been given to how to attract users to adopt D2D communication. In this article we fill the gap by designing incentive mechanisms to encourage users to work under D2D mode. We consider two basic market types, open markets and sealed markets, where users have information of all users or only their own, respectively. For open markets, we design a Stackelberg game based incentive mechanism that can achieve Nash equilibrium. For sealed markets, we design an auction based incentive mechanism that guarantees truthfulness.

Interference-Aware Downlink and Uplink Resource Allocation in HetNets With D2D Support

We address the resource allocation problem in an LTE-based 2-tier heterogeneous network where in-band D2D communications are supported under network control. The different communication paradigms share the same radio resources, thus they may interfere. We devise a dynamic programming approach to efficiently schedule download and upload traffic, by 1) efficiently matching communicating endpoints and 2) assigning radio resources in an interference-aware manner while accounting for the characteristics of the content to be delivered. To this end, we develop an accurate model of the system and apply approximate dynamic programming to solve it. Our solution allows us to deal with realistic large-scale scenarios. In such scenarios, we compare our approach to today's networks where eICIC techniques and proportional fairness scheduling are implemented. Results highlight that our solution increases the system throughput while greatly reducing energy consumption. We also show that D2D mode, established either in the downlink or uplink, can effectively support delivery of highly popular content without significantly harming macrocell or microcell traffic, leading to increased system capacity. Interestingly, we find that D2D mode can also be a low-cost alternative to microcells.

Linear Precoder-Decoder Design of MIMO Device-to-Device Communication Underlaying Cellular Communication

This paper proposes linear precoder-decoder schemes for a multiple-input multiple-output (MIMO) underlay device-to-device (D2D) communication system by considering two D2D modes: two-way relaying based D2D and direct D2D. The D2D communication takes place in the same spectrum as the cellular communication. In the two-way relaying based D2D mode, the relay uses physical layer network coding (PNC). The precoder-decoder design is based on minimizing mean square errors (MSE), which is useful to mitigate interference and to improve the performance of both D2D and cellular communications. Distributed and centralized algorithms are proposed considering bi-directional communication in both D2D and cellular communications. In the direct D2D mode, a similar MSE procedure is adopted, and exact solutions are derived for precoder-decoder matrices. In the numerical results, the optimality and convergence properties of the proposed algorithms are analyzed. Additionally, the system performances are investigated with interference thresholds and maximum available power at the nodes. Two transmit mode selection schemes are considered as dynamic and static selection schemes. Finally, these selection schemes are investigated over an XY grid by varying the position of a given device. The results reveal that the PNC two-way relaying based D2D mode extends the coverage area of D2D communication.