Resource allocation for D2D-assisted haptic communications

Haptic communications is recognized as a promising enabler of extensive services by enabling real-time haptic control and feedback in remote environments,e.g.,teleoperation and autonomous driving.Considering the strict transmission requirements on reliability and latency,Device-to-Device(D2D)communications is introduced to assist haptic communications.In particular,the teleoperators with poor channel quality are assisted by auxiliaries,and each auxiliary and its corresponding teleoperator constitute a D2D pair.However,the haptic interaction and the scarcity of radio resources pose severe challenges to the resource allocation,especially facing the sporadic packet arrivals.First,the contentionbased access scheme is applied to achieve low-latency transmission,where the resource scheduling latency is omitted and users can directly access available resources.In this context,we derive the reliability index of D2D pairs under the contention-based access scheme,i.e.,closed-loop packet error probability.Then,the reliability performance is guaranteed by bidirectional power control,which aims to minimize the sum packet error probability of all D2D pairs.Potential game theory is introduced to solve the problem with low complexity.Accordingly,a distributed power control algorithm based on synchronous log-linear learning is proposed to converge to the optimal Nash Equilibrium.Experimental results demonstrate the superiority of the proposed learning algorithm.

Performance Analysis in SWIPT-Based Bidirectional D2D Communications in Cellular Networks

In this paper,a novel traffic-aware cooperative cognitive radio network that can enable deviceto-device(D2D)communications in cellular system is proposed and investigated.By providing relay cooperation to cellular transmission,D2D users can realize their own two-way communication in the licensed spectrum.Unlike most existing works,in the proposed network,both wireless-powered D2D users can harvest energy via radio-frequency signals received from basic station(BS)through a hybrid protocol which can adaptively utilize both time-switching and powersplitting techniques.Specifically,D2D users perform decode-and-forward operation to transmit signals,and mobile user(MU)employs a selection combining technique.In addition,the performance of both D2D system and cellular system in the proposed network is evaluated by deriving the expressions of their exact outage probability and throughput.Numerical and simulation results validate correctness of derivations and reveal the influence of various system parameters of the proposed network.

3种3D打印模型辅助治疗RobinsonⅡB2型锁骨骨折

背景:随着3D打印技术在医学中的应用及发展,使得骨科内固定手术迈向精准化、个体化,通过3D打印技术获得的等比例骨折模型进行术前模拟、规划,实现了由传统的2D图像向更加形象、精细的立体实物的跨越,让术者提前了解骨折类型、预演复位顺序,进而实现骨折手术的个体化实施,优化了手术过程,带来更佳的术后恢复效果和更少的手术并发症。目的:比较3种3D打印模型结合计算机虚拟复位技术辅助切开复位接骨板内固定和传统切开复位接骨板内固定治疗RobinsonⅡB2型锁骨骨折的临床疗效。方法:将80例RobinsonⅡB2型锁骨骨折患者随机分为试验组(40例)和对照组(40例),试验组利用3种3D打印模型(患侧锁骨骨折模型、计算机模拟锁骨骨折复位后模型、健侧锁骨镜像模型)结合计算机虚拟复位技术在术前进行体外手术预演,最后利用健侧锁骨镜像模型进行3D打印来提前弯折和选择接骨板进行内固定,对照组直接进行切开复位接骨板内固定。比较两组患者入院至手术时间、术中出血量、手术时间、透视次数、对接骨板的折弯次数、骨折愈合时间、并发症发生情况及两组患者治疗前后目测类比评分、Constant肩关节功能评分。结果与结论:试验组患者入院至手术时间长于对照组(P<0.05);试验组患者手术时间、术中透视次数及对接骨板的折弯次数均小于对照组(P<0.05);试验组患者骨折愈合更快,并发症更少(P<0.05);两组患者术中出血量无统计学差异(P>0.05);两组患者Constant评分均有随时间延长而上升的趋势(F=613.50,P<0.001),但组间比较差异无显著性意义(F=0.08,P=0.78),测量次数与分组无交互效应(F=0.27,P=0.66)。两组患者目测类比评分随时间延长而下降(F=1149.55,P<0.001),但组间比较差异无显著性意义(F=0.02,P=0.88),测量次数与分组无交互效应(F=1.02,P=0.36)。结果表明使用3D打印模型结合计算机虚拟复位技术进行术前预演,可以缩短手术时间、减少术中透视及对接骨板折弯的次数,同时具有骨折愈合更快、并发症更少的优势,并能达到与传统切开复位接骨板内固定相似的功能恢复。

An Optimal Algorithm for Resource Allocation in D2D Communication

The number of mobile devices accessing wireless networks isskyrocketing due to the rapid advancement of sensors and wireless communicationtechnology. In the upcoming years, it is anticipated that mobile datatraffic would rise even more. The development of a new cellular networkparadigm is being driven by the Internet of Things, smart homes, and moresophisticated applications with greater data rates and latency requirements.Resources are being used up quickly due to the steady growth of smartphonedevices andmultimedia apps. Computation offloading to either several distantclouds or close mobile devices has consistently improved the performance ofmobile devices. The computation latency can also be decreased by offloadingcomputing duties to edge servers with a specific level of computing power.Device-to-device (D2D) collaboration can assist in processing small-scaleactivities that are time-sensitive in order to further reduce task delays. The taskoffloading performance is drastically reduced due to the variation of differentperformance capabilities of edge nodes. Therefore, this paper addressed thisproblem and proposed a new method for D2D communication. In thismethod, the time delay is reduced by enabling the edge nodes to exchangedata samples. Simulation results show that the proposed algorithm has betterperformance than traditional algorithm.

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.

cyclin D2、Bcl-2在弥漫大B细胞淋巴瘤中的表达意义

目的研究细胞周期蛋白D2(cyclin D2)、B淋巴细胞瘤-2基因(Bcl-2)在弥漫大B细胞淋巴瘤(DLBCL)中的表达意义。方法采用回顾性分析,观察对象为2017年3月至2022年3月入东莞市人民医院就诊的80例DLBCL患者与20例淋巴组织反应性增生(RLH)患者,分别设定为研究组与对照组,两组患者均经术后病理检查确诊,术前未行任何治疗。选取免疫组织化学法测定两组cyclin D2、Bcl-2蛋白表达情况,对cyclin D2、Bcl-2表达之间的相互关系及与DLBCL患者病理特征相关性进行分析。结果研究组cyclin D2蛋白阳性率、Bcl-2蛋白阳性率分别为33.75%(27/80)、62.50%(50/80),对照组cyclin D2蛋白阳性率、Bcl-2蛋白阳性率分别为5.00%(1/20)、10.00%(2/20);研究组cyclin D2蛋白阳性率、Bcl-2蛋白阳性率较对照组更高,差异均有统计学意义(P<0.05)。cyclin D2蛋白表达、Bcl-2蛋白表达与DLBCL患者的免疫分型、Ann Arbor分期有明显相关性(P<0.05),与组织类型、肿瘤部位、性别及年龄无明显相关性(P>0.05)。DLBCL中cyclin D2与Bcl-2的表达呈正相关(r=1.000,P<0.05)。结论cyclin D2、Bcl-2在DLBCL中呈高表达,可能参与了DLBCL的发生及发展,两者具有协同作用,可辅助评价生物恶性程度。

桑黄多糖调控MICB/NKG2D信号通路增强机体对脑胶质瘤细胞的免疫监视作用

目的:探讨桑黄多糖对脑胶质瘤细胞免疫监视的增强作用及其对主要组织相容性复合物Ⅰ链相关基因B(MICB)/自然杀伤细胞活化性受体2D(NKG2D)信号通路的调控机制。方法:取6~8周龄C57BL/6小鼠60只和GL261细胞株培养传代,随机取其中的50只小鼠建立脑胶质瘤模型,其余10只小鼠记为对照组,另将建模成功小鼠采用随机数字表分组,榄香烯组予以100 mg/kg榄香烯与1 ml/100 g生理盐水混匀灌胃,桑黄多糖各剂量组分别予以50、100、200 mg/kg桑黄多糖溶于1 ml/100 g生理盐水中灌胃,对照组和模型组均予以等量生理盐水灌胃,均1次/d,共4周。干预后处死小鼠,比较各组瘤重和抑瘤率;苏木素-伊红(HE)染色观察瘤组织病理变化;以CD57抗体标记检测瘤组织中NK细胞浸润;实时-逆转录聚合酶链反应(RT-qPCR)检测瘤组织主要组织相容性复合物Ⅰ链相关基因A(MICA)、MICB、UL16结合蛋白1(ULBP1)、UL16结合蛋白2(ULBP2)、UL16结合蛋白3(ULBP3)mRNA表达,Western blot检测瘤组织MICA、MICB、ULBP1、ULBP2、ULBP3蛋白表达;采用磁珠亲和细胞分选法分离各组组织中NK细胞,采用流式细胞仪检测其表面NKG2D活性。结果:与模型组比较,榄香烯组和桑黄多糖各剂量组瘤重下降,抑瘤率升高,瘤组织细胞变性、坏死增多,NK细胞浸润增多,MICA、ULBP2、ULBP3 mRNA和蛋白表达下降,MICB、ULBP1 mRNA和蛋白表达升高,且NK细胞表面NKG2D活性增强,上述差异均有统计学意义(P<0.05);桑黄多糖的作用呈剂量依赖性,桑黄多糖低剂量组和榄香烯组所有指标比较差异均无统计学意义(P>0.05)。结论:桑黄多糖可抑制脑胶质瘤增长,促进瘤细胞变性、坏死,增加NK细胞浸润,推测d与调控MICB/NKG2D信号通路,增加MICB、ULBP1表达和NK细胞表面NKG2D活性,下调MICA、ULBP2、ULBP3表达,增强对脑胶质瘤细胞的免疫监视有关。

Collaborative D2D Communication in Relay Networks with Energy Harvesting

Although the collaborative transmission of cellular network and device-to-device(D2D)pairs can improve spectrum utilization,it also results in the matual interference,which may be fatal for low-energy D2D pairs.Based on this,we propose in this paper a collaborative D2D transmission scheme with erergy harvesting(CDTEH)in a relay network,where D2D pairs are allowed to access the spectrum of relay network to accomplish their own transmission.In particular,the relay with energy harvesting is arranged to not only expand cellular transmission range but also assist D2D and cellular users to eliminate the mutual interference.To evaluate the performance,rate-energy(R-E)region is introduced.Based on the model,a data rate maximization problem of D2D pair is formulated,subject to a transmission demand of the cellular user and the optimal solution is acquired.Finally,numerical results are provided to validate the proposed scheme improves the data rate of D2D pair ensuring the cellular transmission requirement.

D2D communication in a cellular network based on link adaptation with truncated ARQ

A device-to-device （D2D） communication mode underlaying cellular network in a single- cell environment is introduced. A practical method based on link adaptation with automatic repeat request （ARQ） is presented. Link adaptation technique, which combines adaptive modulation and coding （ AMC ） with truncated ARQ, can maximize the cellular UEs＇ data rate under prescribed delay and performance constraints. The proposed method can maximize the total transmission rate when an outage probability is determined. Numerical results show that with proper power control, the in- terference between the two links can be coordinated to increase the sum rate without overwhelming the cellular service.

LM-3B Successfully Launched Communications Technology Test Satellite 2

At 23:18 Beijing time on January 5,a LM-3B carrier rocket lifted off from the Xichang Satellite Launch Center,sending a communication technology test satellite into its preset orbit.This successful launch was a good start for China’s launch missions in 2017.The Communications Technology Test Satellite 2 was developed by the Shanghai Academy of Spaceflight Technology.It is a next-generation telecom-

健脾补肾法对人结直肠癌移植瘤组织TLR4、RAGE、NF-κB及CD34、D2-40的影响

目的探讨健脾补肾法对人结直肠癌移植瘤组织TLR4、RAGE、NF-κB及CD34、D2-40的影响。方法于裸鼠右腿内侧接种人结肠癌细胞,建立人结肠癌裸鼠皮下移植瘤模型,15d后脱颈处死剥离瘤体。对照组用生理盐水灌胃,实验组用健脾补肾中药灌胃,免疫组化法检测2组移植瘤组织中TLR4、RAGE、NF-κB及CD34、D2-40的表达。结果免疫组化显示,与对照组相比,实验组的移植瘤组织中TLR4、RAGE、NF-κB的表达均明显下调(P<0.05),微血管CD34及淋巴管D2-40也明显下调(P<0.005)。结论健脾补肾法能明显下调人结直肠癌移植瘤组织炎症受体TLR4及RAGE、核转录因子NF-κB、肿瘤新生血管标记物CD34及肿瘤新生淋巴管标记物D2-40的表达。

重组干扰素α-2b治疗小儿呼吸道合胞病毒毛细支气管炎对肺表面活性蛋白D和转化生长因子-β的影响

目的探讨重组干扰素α-2b治疗小儿呼吸道合胞病毒毛细支气管炎对肺表面活性蛋白D(SP-D)、转化生长因子-β(TGF-β)的影响。方法选取2019年3月至2020年10月于本院儿科就诊的174例呼吸道合胞病毒所致的毛细支气管炎患儿作为研究对象,按照随机数字表法分为对照组与观察组,每组87例。对照组给予布地奈德混悬液联合孟鲁司特钠治疗,观察组在对照组基础上增加重组人干扰素α-2b治疗,比较两组临床疗效、临床症状消失时间及住院时间、实验室指标(SP-D、TGF-β)及不良反应发生率。结果观察组治疗总有效率为96.55%,高于对照组的88.51%,差异有统计学意义(P<0.05)。观察组喘憋消失时间、肺部湿啰音消失时间、咳嗽消失时间及住院时间均短于对照组,差异有统计学意义(P<0.05)。治疗前,两组SP-D、TGF-β水平比较差异无统计学意义;治疗7 d后,两组SP-D水平低于治疗前,TGF-β水平高于治疗前,且观察组SP-D水平低于对照组,TGF-β水平高于对照组,差异有统计学意义(P<0.05)。两组不良反应发生率比较差异无统计学意义。结论重组干扰素α-2b治疗小儿呼吸道合胞病毒致毛细支气管炎疗效显著,有助于加快缓解患儿临床症状,降低SP-D水平,提高TGF-β水平,且安全性较高,值得临床推广应用。

Energy Efficiency and Spectrum Efficiency in Underlay Device-to-Device Communications Enabled Cellular Networks

In this paper, we investigate the energy efficiency and spectrum efficiency, including one-hop device-to-device(D2D) communications mode and two-way amplify-and-forward(AF) relaying D2D communications mode in underlay D2D communications enabled cellular networks. An analysis of average energy efficiency and spectrum efficiency are developed and closed-form expressions are obtained for two types of D2D communications modes under the effect of Rayleigh fading channel, path loss, and co-channel interference. Analytical results are validated through numerical simulations. Based on the simulation, the effects of the interference, the distance between D2D pair and the position of relay node on the energy efficiency and spectrum efficiency of D2D communications are investigated. The optimal D2D transmission powers of these two modes to maximize the energy efficiency are also investigated.

A Robust Resource Allocation Scheme for Device-to-Device Communications Based on Q-Learning

One of the most effective technology for the 5G mobile communications is Device-to-device(D2D)communication which is also called terminal pass-through technology.It can directly communicate between devices under the control of a base station and does not require a base station to forward it.The advantages of applying D2D communication technology to cellular networks are:It can increase the communication system capacity,improve the system spectrum efficiency,increase the data transmission rate,and reduce the base station load.Aiming at the problem of co-channel interference between the D2D and cellular users,this paper proposes an efficient algorithm for resource allocation based on the idea of Q-learning,which creates multi-agent learners from multiple D2D users,and the system throughput is determined from the corresponding state-learning of the Q value list and the maximum Q action is obtained through dynamic power for control for D2D users.The mutual interference between the D2D users and base stations and exact channel state information is not required during the Q-learning process and symmetric data transmission mechanism is adopted.The proposed algorithm maximizes the system throughput by controlling the power of D2D users while guaranteeing the quality-of-service of the cellular users.Simulation results show that the proposed algorithm effectively improves system performance as compared with existing algorithms.

Ergodic Rate Analysis on Applying Antenna Selection in D2D Communication Underlaying Cellular Networks

By reusing the spectrum of a cellular network, device-to-device(D2D) communications is known to greatly improve the spectral efficiency bypassing the base station(BS) of the cellular network. Antenna selection is the most cost efficient scheme for interference management, which is crucial to D2D systems. This paper investigates the achievable rate performance of the D2D communication underlaying the cellular network where a multiple-antenna base station with antenna selection scheme is deployed. We derive an exact closed-form expression of the ergodic achievable rate. Also, using Jensen's inequality, two pairs of upper and lower bounds of the rate are derived and we validate the tightness of the two sets of bounds. Based on the bounds obtained, we analyze the ergodic achievable rate in noise-limited scenario, interference-limited high SNR scenario and larger-scale antenna systems. Our analysis shows that the presence of D2D users could be counter-productive if the SNR at cellular UE is high. Further analysis shows that the relationship between the ergodic rate and the number of antennas it positive, but keeps decreasing as the antenna number increasing. These show the inefficiency of antenna selection in D2D interference management.

A Joint Resource Allocation Algorithm for D2D Communication

The emergence of multimedia services has meant a substantial increase in the number of devices in mobile networks and driving the demand for higher data transmission rates.The result is that,cellular networks must technically evolve to support such higher rates,to be equipped with greater capacity,and to increase the spectral and energy efficiency.Compared with 4G technology,the 5G networks are being designed to transmit up to 100 times more data volume with devices whose battery life is 10 times longer.Therefore,this new generation of networks has adopted a heterogeneous and ultra-dense architecture,where different technological advances are combined such as device-to-device(D2D)communication,which is one of the key elements of 5G networks.It has immediate applications such as the distribution of traffic load(data offloading),communications for emergency services,and the extension of cellular coverage,etc.In this communication model,two devices can communicate directly if they are close to each other without using a base station or a remote access point.Thus,eliminating the interference between theD2Dand cellular communication in the network.The interference management has become a hot issue in current research.In order to address this problem,this paper proposes a joint resource allocation algorithm based on the idea of mode selection and resource assignment.Simulation results showthat the proposed algorithm effectively improves the systemperformance and reduces the interference as compared with existing algorithms.

Spark Spectrum Allocation for D2D Communication in Cellular Networks

The device-to-device(D2D)technology performs explicit communication between the terminal and the base station(BS)terminal,so there is no need to transmit data through the BS system.The establishment of a short-distance D2D communication link can greatly reduce the burden on the BS server.At present,D2D is one of the key technologies in 5G technology and has been studied in depth.D2D communication reuses the resources of cellular users to improve system key parameters like utilization and throughput.However,repeated use of the spectrum and coexistence of cellular users can cause co-channel interference.Aiming at the interference problem under the constraint of fair resource allocation and improving the system throughput,this paper proposes an effective resource optimization scheme based on the firework method.The main idea is to expand the weighted sum rate and convert the allocated resource expression into fireworks to determine the correlation matrix.The simulation results show that,compared with the existing scheme,this scheme improves system performance by reducing interference.

Outage Probability Based on Relay Selection Method for Multi-Hop Device-to-Device Communication

To improve the connectivity of device-to-device(D2D)communication between delay-assisted vehicles,a multi-hop D2D relay selection strategy based on outage probability is proposed.The algorithm firstly clusters the relay users based on the distance of D2D users,and determines the number of one-hop relay nodes through the outage probability threshold.Two-hop relay nodes directly select the same number of relays as one-hop relay nodes according to the descending order of signal noise ratio(SNR)to establish a square matrix.The Hungarian algorithm is used to assign the relay nodes of two clusters to complete the inter relay communication.Finally,the information is sent to the D2D receiver by combining technology.The simulation results show that this algorithm can reduce the cost of relay probing process and the outage probability of system in multi-hop D2D relay communication.

Energy efficiency optimization of relay-assisted D2D two-way communications with SWIPT

Aiming at the energy consumption of long-distance device-to-device(D2D) devices for two-way communications in a cellular network,this paper proposes a strategy that combines two-way relay technology(TWRT) and simultaneous wireless information and power transfer(SWIPT) technology to achieve high energy efficiency(EE) communication.The scheme first establishes a fractional programming problem to maximize EE of D2D,and transforms it into a non-fractional optimization problem that can be solved easily.Then the problem is divided into three sub-problems:power control,power splitting ratios optimization,and relay selection.In order to maximize EE of the D2D pair,the Dinkelbach iterative algorithm is used to optimize the transmitted power of two D2D devices simultaneously;the one-dimensional search algorithm is proposed to optimize power splitting ratios;an improved optimal relay selection scheme based on EE is proposed to select relay.Finally,experiments are carried out on the Matlab simulation platform.The simulation results show that the proposed algorithm has faster convergence.Compared with the one-way relay transmission and fixed relay algorithms,the proposed scheme has higher EE.

柴胡醋制前后柴胡皂苷a、b_2、c、d的LC-MS/MS法测定及比较

采用LC-MS/MS法对醋制前后柴胡中的Ⅰ型柴胡皂苷a、c、d与Ⅱ型柴胡皂苷b2进行含量测定,色谱柱为KinetexTMC18(50 mm×4.6 mm,2.6μm),流动相为水-乙腈-甲醇三元梯度洗脱;检测系统为电喷雾离子源(ESI)-三重四级杆质谱仪,ESI负离子模式检测,待测成分与内标均采用负离子加合物作为选择性反应监测(SRM)的前体离子,以[M+HCOO]-/[M-H]-作为SRM检测离子对。方法学验证结果显示,所建立的方法灵敏度高、专属性好,可作为柴胡生品及醋炙品的质量控制方法。含量测定结果表明,醋制过程引发了由Ⅰ型柴胡皂苷向Ⅱ型的转化,醋制后柴胡皂苷b2的含量明显增加,对柴胡醋炙品的质量控制应同时考虑对Ⅰ、Ⅱ型柴胡皂苷柴胡皂苷进行测定。