Joint relay selection and resource allocation in cooperative device-to-device communications

Device-to-device (D2D) communications allow proximate cellular user equipments (UEs) to communicate with each other directly under the control of base station (BS). In this paper, considering the selection relaying (SR) rule which allows a subset of potential relays to forward the source’s data to the corresponding destination, we first establish a multi-relay system model where a D2D UE can act as not only a source but also a potential relay for another D2D link, and then analyze the cooperation behaviors among selfish UEs. Next a simple strategy is proposed to deal with the relay selection problem, and then the fair and efficient resource sharing problem among cooperating D2D UEs is formulated as a bargaining game. Since the game function is non-convex, we turn to an iterative method by introducing an auxiliary function to get the proportional fair resource allocation results. The system efficiency and fairness are proved by numeral simulation results.     

A non-iterative resource allocation strategy for device-to-device communications in underlaying cellular networks

We develop a joint spectrum sharing and power control strategy to increase the admissible number of device-to-device (D2D) links in an underlaying cellular network while guaranteeing the quality-of-service (QoS) of both D2D links and cellular users (CUs). The proposed spectrum sharing algorithm, termed as interference-filling (IF), examines whether the SINR requirements of all the existing CUs and D2D users can be met if a new D2D pair is admitted. In the sequel, two power control schemes are proposed to check the resultant interference level and increase the transmit power of the admitted D2D pairs group-by-group to further improve the system throughput. IF algorithm is based on the ordering statistics of the interference amounts from D2D transmitters to CUs, thus neither grid searching nor iteration is needed. Furthermore, the two proposed power control schemes are in closed-forms. These two favorable properties make the proposed strategy cost-effective and computationally efficient. Numerical results show the effect of the proposed IF and power control schemes in term of admissible D2D pairs and system sum rate.     

多导体电力电缆载波通信系统中的资源分配

通过实测的多导体电力电缆串扰耦合系数,分析其串扰规律.结合电力线通信的约束,介绍其功率和速率自适应相结合的混合资源分配模型.针对拉格朗日乘子法求解有信号串扰的资源分配局限性,对传输信号及其相关参数进行线性变换以实现信道解耦和将复杂的资源分配分解为多个简单的等效信道优化问题.结合经典注水思想提出一种基于SVD-GMD解耦和脏纸编码的比特加减算法,为了对比还提出基于SVD解耦的比特添加查表算法.在典型的多导体电力电缆环境下,仿真结果表明比特加减算法有效地消除信道间的串扰和利用等效信道的相似性,其在保持系统性能最优的同时有效地降低了资源分配的复杂度.     

Multi-channel-based scheduling for overlay inband device-to-device communications

In this paper, we consider the problem of distributed scheduling for overlay inband device-to-device (D2D) communication systems that employ an orthogonal frequency division multiple access physical layer technology. To improve the spatial reuse gain, we propose a multi-channel-based scheduling algorithm that divides the overall radio resource dedicated to D2D communication into multiple data channels and schedules the links allocated to each channel based on a signal-to-interference-aware priority-based scheduling method. Further, we develop a cross-layer queueing model to analyze the medium-access-control layer performance of the proposed scheduling algorithm and compare the analytic results with the simulation results. We demonstrate that the proposed scheduling algorithm outperforms the existing single one-channel-based algorithm to provide lower packet dropping probability, higher spectral efficiency, and lower packet delay.     

一种适用于D2D通信的启发式接入算法

直通通信（Device-to-Device,D2D）技术是5G移动通信的关键技术之一,蜂窝网络中的D2D通信用户接入技术及其性能研究等已成为热点问题。基于一种新型随机几何网络模型,通过研究D2D用户对蜂窝用户的上行链路频谱资源的复用,提出了一种D2D通信启发式接入算法,并同随机接入算法进行了比较分析。仿真结果表明,随机几何模型易于分析链路的信干噪比,更符合未来移动通信密集组网和用户分布特点;该模型下的启发式算法比随机算法的性能更优,算法具有收敛快、接入性能好和接入简单的特点,具有更好的实用价值。     

Resource allocation and power control for underlay device-to-device communication in fractional frequency reuse cellular networks

The current state of device-to-device (D2D) communication in the presence of cellular network addresses two major challenges of interference as well as throughput inadequacy. Specifically, a D2D communication underlaying fractional frequency reuse (FFR) cellular network exhibits rather high interferences due to higher occurrence of band crossing within a shared spectrum. However, due to the considerable impact of D2D communications on spectral efficiency and system capacity, the remedy for those issues may include efficient techniques of interference mitigation and average spectral efficiency maximization. In this paper, we propose a resource block (RB) allocation scheme to reduce the co-channel interference by providing and maintaining adequate distance between D2D user equipment (DUE) and cellular user equipment (CUE), and between the macrocell base station and DUEs that are using the same RB. In the proposed scheme, we initially introduce a plan with one omnidirectional and three directional antennas be used to serve the CUE in the inner and outer regions of the FFR cell, respectively. In addition, DUE in each region uses the RBs that are orthogonal to those used by CUE. It is shown that by using two different ranges for inner region of cellular and D2D communication, the overall performance is improved. Furthermore, we formulate an optimization problem for maximizing average spectral efficiency while guaranteeing CUE signal-to-interference-plus-noise-ratio and achieve efficient solutions to the different average spectral efficiency maximization problems. The results demonstrate the efficiency of the proposed scheme. In addition, it is shown that significant improvement in system spectral efficiency is obtained through the optimization of DUE power. That is, the achieved throughput is much higher than that of the random resource allocation and 1.5–2 times of the previous works.     

Social-aware device-to-device communications underlaying cellular networks

This article put forward a resource allocation scheme aimming at maximizing system throughput for devide-to-device(D2D) communications underlying cellular network. Firstly, user closeness is defined and calculated through social information including friendship, interest similarity and communication strength to represent the willingness of user to share the spectrum resource with others. Then a social-aware resource allocation problem is formulated to maximize the system throughput while guaranteeing the quality of service(QoS) requirements of both the admissible D2D pairs and then the power of both CUs and D2D pairs is efficiently allocated. Finally CUs and D2D pairs are matched to reuse the spectrum resource in consideration of both user closeness and physical conditions. Simulation results certify the effectiveness of the proposed scheme which significantly enhances the system throughput compared with the existing algorithms.     

Truthful budget constrained auction for device-to-device relaying packet allocation

Taking advantage of peer-to-peer transmission underlying cellular networks, device-to-device (D2D) communications offer various benefits such as coverage extension, traffic offloading, and improved energy efficiency. In this paper, we focus on a promising scenario where a D2D local area network is formed to relay packets for an out-of-coverage source device. A one-sided auction model is formulated from a unique perspective in which the source device decides the allocation of its packets among the helpers and charges reserve payments to the helpers according to their bids. The winning helpers only collect rewards from the source’s deposit at the base station when the assigned packets are successfully relayed. In this model, we further take into account the budget constraints of the helpers to capture the helpers’ resource limits and the risks that the helpers are willing to take. Based on this model, we propose three auction mechanisms targeting economic properties such as individual rationality, efficiency, and truthfulness. An enhanced Martello & Toth algorithm is first developed for the VCG-based auction to determine packet allocation that optimizes the source’s quality of service. The probabilistic entrance auction mechanism uses sequential second price auction to achieve a low computational cost. The randomized mechanism involves a randomization over the above two mechanisms to satisfy certain requirement for social welfare while minimizing the computational time. We also conduct extensive simulations to examine the performance of the proposed mechanisms.     

LTE-Advanced载波聚合中的无线资源管理研究

载波聚合是LTE-Advanced系统的关键技术之一。文章中重点介绍了载波聚合中的移动性无线资源管理（RRM：Radio Resource Manage-ment）机制。在引入该机制的基础上,传统的正比公平（PF：proportional fair）调度算法并不能够很好地保证用户之间在资源分配方面的公平性,因此提出了Balanced PF（BPF）算法。从系统级仿真结果可以看出,与传统的PF算法相比,BPF算法可以提升边缘用户的吞吐量性能,改善用户之间的公平性。     

Energy-efficient resource allocation scheme for device-to-device communication underlaying LTE-A uplink

To cope with the co-channel interference between cellular links and device-to-device (D2D) links concurrently transmitting with the long term evolution-advanced (LTE-A) uplink spectrum,a joint resource allocation scheme was pro-posed to maximize the global energy efficiency of D2D links.The above problem can be decomposed into the power control subproblem and the channel assignment subproblem.Specifically,the power control subproblem can be optimally solved with the help of Dinkelbach method and Lagrange duality.Based on the above results,the channel assignment subproblem turns out to be the set packing problem which was generally NP-hard problem,Therefore,a heuristic algo-rithm was further devised to achieve a tradeoff between performance and complexity.Simulations show that the proposed joint resource allocation scheme outperforms the ones where only single resource variable is optimized,and it achieves the polynomial-time complexity at only minor performance loss when compared to the global optimum.     

LTE-Advanced中ePDCCH信道的资源映射

随着LTE-Advanced系统中,信道在容量和其他性能上的大幅度提高,控制信道技术成为决定数据信道性能好坏的关键因素。通过研究ePDCCH的资源结构,对ePDCCH的传输方式等重要特征进行了分析,并针对控制信道的资源分配问题,对集中式和分布式两种传输类型分别提出了增强型资源粒子组(EREG)到增强型控制粒子(ECCE)的资源映射方式。最后,根据对实际映射关系图的分析和性能评估,验证了所设计的映射方案的合理性和可行性。     

基于安全中断概率的D2D安全接入策略

针对D2D蜂窝系统通信安全性受资源限制的问题,考虑到蜂窝链路和D2D链路的同频干扰能够为两者带来安全增益,基于此,提出一种基于安全中断概率的D2D用户接入策略。首先理论分析了蜂窝用户和D2D用户的安全中断概率,并给出了基于安全中断概率最小化的D2D用户功率优化算法。在上述分析的基础上,选择安全中断概率最小的D2D用户接入复用蜂窝用户的无线资源,同时提高D2D通信链路和蜂窝上行链路的安全性。最后,仿真结果证明了所提算法的有效性。     

Precoding and power allocation algorithms for device-to-device communication in massive MIMO networks

Device-to-device communication (D2D) and massive multiple input multiple output (MIMO) systems are two emerging technologies that are being considered to improve the performance of next generation wireless cellular systems. In D2D, two mobile nodes communicate directly without traversing the base station (BS). Consequently, interference management, coordination, and/or cancellation techniques have to be adopted to target the problem of mutual interference between the D2D devices and the BS (or the normal mobiles nodes connected to the BS). In this paper, we investigate the problem of BS precoder design and D2D devices power allocation in the downlink of a single-cell network assuming existence of D2D devices as well as massive MIMO at the BS. We propose algorithms to maximize the sum of the achievable data rates of the D2D pairs while maintaining quality of service constraints on the cellular user equipment, which communicate normally with the BS. We also propose two algorithms for the precoding problem; the first is based on semi-definite programming while the second is based on gradient descent algorithms. Moreover, we investigate two solutions for the power allocation problem; the first solves an approximate convex optimization problem iteratively while the second is a suboptimal, but far less complex, heuristic. Finally, we propose a technique to apply the mentioned solutions when only partial channel state information is available at the BS. Simulation results show that the proposed solutions are superior to the conventional precoding and power allocation schemes.     

Optimal transmission mode proportion for heterogeneous networks of cellular and device-to-device communications

This paper discusses about the optimal mode allocation for the heterogeneous networks, in which the network can schedule users working in the device-to-device （D2D） mode or cellular mode. The D2D user is allowed to reuse the uplink resource of cellular system and the problem is formed as a sum-capacity optimization issue with outage constraints for both cellular and D2D links. The method for the optimal user proration is proved to be divided into three cases according to the total user density： when the total user density is small, the optimal proration trends to all users utilizing one mode; when the total user density is large, the optimal proration is all of users choosing D2D mode; and when the total user density situates in the between, there is a unique optimal transmission mode proportion for the hybrid networks to maximize its sumcapacity. The simulation results demonstrate the validity of the conclusions in the analysis part.     

Resource and power allocation for achieving rate fairness in D2D communications overlaying cellular networks

Wireless Networks - This paper presents a novel resource and power allocation scheme for device-to-device (D2D) communications overlaying cellular networks. The proposed scheme is implemented in...     

End-to-end energy-efficient resource allocation in device-to-device communication underlaying cellular networks

A proposed resource allocation(RA) scheme is given to device-to-device(D2D) communication underlaying cellular networks from an end-to-end energy-efficient perspective, in which, the end-to-end energy consumptions were taken into account. Furthermore, to match the practical situations and maximize the energy-efficiency(EE), the resource units(RUs) were used in a complete-shared pattern. Then the energy-efficient RA problem was formulated as a mixed integer and non-convex optimization problem, extremely difficult to be solved. To obtain a desirable solution with a reasonable computation cost, this problem was dealt with two steps. Step 1, the RU allocation policy was obtained via a greedy search method. Step 2, after obtaining the RU allocation, the power allocation strategy was developed through quantum-behaved particle swarm optimization(QPSO). Finally, simulation was presented to validate the effectiveness of the proposed RA scheme.     

Energy-efficient resource allocation model for device-to-device communication in 5G wireless personal area networks

In general, there are several many devices that can overload the network and reduce performance. Devices can minimize interference and optimize bandwidth usage by using directional antennas and by avoiding overlapping communication ranges. In addition, devices need to carefully manage their use of resources, such as bandwidth and energy. Bandwidth is limited in wireless personal area networks (WPANs), so devices need to carefully select which data to send and receive. In this paper, an intelligent performance analysis of energy-efficient resource optimization model has been proposed for device-to-device (D2D) communication in fifth-generation (5G) WPAN. The proposed energy-efficient resource allocation in D2D communication is important because it helps reduce energy consumption and extend the lifespan of devices that are communicating with each other. By allocating resources in an efficient manner, communication between two devices can be optimized for maximum efficiency. This helps reduce the amount of energy needed to power the communication, as well as the amount of energy needed to power the device that is communicating with another device. Additionally, efficient resource allocation helps reduce the overall cost of communication, as the use of fewer resources results in a lower overall cost. The proposed efficient resource allocation helps reduce the environmental impact of communication, as less energy is used for communication. The proposed energy-efficient resource allocation model (EERAM) has reached 92.97% of energy allocation, 88.72% of power allocation, 87.79% of bandwidth allocation, 87.93% of spectrum allocation, 88.43% of channel allocation, 25.47% of end-to-end delay, 94.33% of network data speed, and 90.99% of network throughput.     

Efficient spectrum allocation for personal communications services

Principal features of personal communications service (PCS), namely, ubiquity, portability, and integration of voice and data, are examined, highlighting some issues affecting the spectrum choices before today's policymakers. Spectrum issues are discussed, focusing on two tools for promoting efficient spectrum use: the use of generic service definitions and band assignment     

Power allocation for device-to-device communication underlaying cellular networks under a probabilistic eavesdropping scenario

In this paper, we focus on the issue of security due to the open structure of the D2D Communication Underlaying Cellular Networks. In such an open scenario, the problem of interference is very serious. But luckily, the interference can be helpful from a perspective of the physical layer security. The interference caused by D2D communication could be helpful against eavesdroppers to enhance the secure communication of the cellular users when the value of the interference is proper. Note this, the physical layer security of the cellular users can be enhanced with the proper interference management based on the power allocation in D2D communication underlaying cellular networks in a probabilistic eavesdropping scenario. The problem is modeled as a Stackelberg game model. In the model, all cellular users are modeled as followers while the D2D pair is modeled as leader. A semi-centralized power allocation algorithm is proposed to converge to the Stackelberg Equilibrium. And the equilibrium is the final power allocation scheme we want. It is proved that the proposed algorithm can conclude in finite-time iterations. Numerical simulation results show that our proposed power allocation algorithm can obtain larger secrecy data rate, than the other two power allocation algorithms.