Cooperative Rate Splitting Transmit Design for Full-Duplex-Enabled Multiple Multicast Communication Systems

This paper examines the performance of Full-Duplex Cooperative Rate Splitting(FD-CRS)with Simultaneous Wireless Information and Power Transfer(SWIPT)support in Multiple Input Single Output(MISO)networks.In a Rate Splitting Multiple Access(RSMA)multicast system with two local users and one remote user,the common data stream contains the needs of all users,and all users can decode the common data stream.Therefore,each user can receive some information that other users need,and local users with better channel conditions can use this information to further enhance the reception reliability and data rate of users with poor channel quality.Even using Cell-Center-Users(CCUs)as a cooperative relay to assist the transmission of common data can improve the average system speed.To maximize the minimum achievable rate,we optimize the beamforming vector of Base Station(BS),the common streamsplitting vector,the cooperative distributed beamvector and the strong user transmission power under the power budget constraints of BS and relay devices and the service quality requirements constraints of users.Since the whole problem is not convex,we cannot solve it directly.Therefore,we propose a low complexity algorithm based on Successive Convex Approximation(SCA)technology to find the optimal solution to the problemunder consideration.The simulation results show that FD C-RSMA has better gain andmore powerful than FD C-NOMA,HD C-RSMA,RSMA and NOMA.

Influence of backfilling rate on the stability of the"backfilling bodyimmediate roof"cooperative bearing structure

To reduce the cost of backfilling coal mining and utilize the underground space of coal mines,a new backfilling mining method with low backfilling rate called constructional backfilling coal mining(CBCM)is proposed.The "backfilling body-immediate roof" cooperative bearing structure of CBCM is analyzed by establishing the model of the medium thick plate on an elastic foundation.The influence of the backfilling rate on the stability of overlying strata is analyzed by the numerical simulation experiment.The control effect of CBCM is verified by a physic similar simulation test.The economic benefit of CBCM is analyzed.The conclusions are:the deformation characteristics of the immediate roof and critical backfilling spacing in CBCM can be analyzed based on the Hu Haichang’s theory.Exerting the bearing capacity of the immediate roof is beneficial to the stability of the overlying strata.The CBCM has a good control effect on the overburden in Xinyang Mine when the backfilling rate is lower than 25%.The backfilling cost of per ton coal is 37.39 yuan/t when the backfilling rate is 13.7%,with a decrease rate of 56.63%than the full-filling.The research results can provide theoretical support for the application of CBCM in coal mining.

Deep Unfolding for Cooperative Rate Splitting Multiple Access in Hybrid Satellite Terrestrial Networks

Rate splitting multiple access(RSMA)has shown great potentials for the next generation communication systems.In this work,we consider a two-user system in hybrid satellite terrestrial network(HSTN)where one of them is heavily shadowed and the other uses cooperative RSMA to improve the transmission quality.The non-convex weighted sum rate(WSR)problem formulated based on this model is usually optimized by computational burdened weighted minimum mean square error(WMMSE)algorithm.We propose to apply deep unfolding to solve the optimization problem,which maps WMMSE iterations into a layer-wise network and could achieve better performance within limited iterations.We also incorporate momentum accelerated projection gradient descent(PGD)algorithm to circumvent the complicated operations in WMMSE that are not amenable for unfolding and mapping.The momentum and step size in deep unfolding network are selected as trainable parameters for training.As shown in the simulation results,deep unfolding scheme has WSR and convergence speed advantages over original WMMSE algorithm.

BOUNDARY BLOW-UP RATE OF THE LARGE SOLUTION FOR AN ELLIPTIC COOPERATIVE SYSTEM

In this article we consider positive large solution of cooperative systems of the form -△u1=λ1u1 + a1u1u2^q1 -b1(x)u1^p1+1,-△u2=λ2u2 + a2u1^q2u2 -b2(x)u2^p2+1 in a bounded smooth domainΩ■ R^N(λi ∈ R, ai, bi>0, 0 < qi < pj, i, j ∈{1, 2}, i ≠ j), Based on the construction of certain sup and sub-solution, we show existence, uniqueness and blow-up rate of the large solution.

SR-DCSK Cooperative Communication System with Code Index Modulation:A New Design for 6G New Radios

This paper proposes a high-throughput short reference differential chaos shift keying cooperative communication system with the aid of code index modulation,referred to as CIM-SR-DCSK-CC system.In the proposed CIM-SR-DCSK-CC system,the source transmits information bits to both the relay and destination in the first time slot,while the relay not only forwards the source information bits but also sends new information bits to the destination in the second time slot.To be specific,the relay employs an N-order Walsh code to carry additional log_(2)N information bits,which are superimposed onto the SRDCSK signal carrying the decoded source information bits.Subsequently,the superimposed signal carrying both the source and relay information bits is transmitted to the destination.Moreover,the theoretical bit error rate(BER)expressions of the proposed CIMSR-DCSK-CC system are derived over additive white Gaussian noise(AWGN)and multipath Rayleigh fading channels.Compared with the conventional DCSKCC system and SR-DCSK-CC system,the proposed CIM-SR-DCSK-CC system can significantly improve the throughput without deteriorating any BER performance.As a consequence,the proposed system is very promising for the applications of the 6G-enabled lowpower and high-rate communication.

Enhanced quadrature signaling-based cooperative transmission with full rate and full diversity

Quadrature signaling-based cooperative transmission is an efficient and simple scheme to obtain spatial diversity.However,this scheme causes date rate loss compared with direct transmission.In this work,our focus is on recovering from the data rate loss while simultaneously achieving spatial diversity.Particularly,an enhanced quadrature signaling-based cooperative scheme was designed,which can realize full-rate transmission by using the signal space diversity(SSD)technique.Then,accurate bit error rate(BER)expression for the full-rate scheme was derived over independent and non-identically distributed(INID)Rayleigh fading channels.Specifically,a closed-form BER expression is obtained,which is quite tight over the whole SNR range,and thus allows for rapid and efficient evaluation of system performance under various channel conditions.Moreover,an asymptotic approximation of the BER was derived to show that the full-rate scheme can achieve full diversity.Simulation results verify the tightness of the analysis and show that the full-rate scheme significantly outperforms the traditional quadrature signaling-based scheme by about 2 dB with the same complexity order.

OPTIMAL POWER ALLOCATION WITH AF AND SDF STRATEGIES IN DUAL-HOP COOPERATIVE MIMO NETWORKS

Dual-hop cooperative Multiple-Input Multiple-Output (MIMO) network with multi-relay cooperative communication is introduced. Power allocation problem with Amplify-and-Forward (AF) and Selective Decode-and-Forward (SDF) strategies in multi-node scenario are formulated and solved respectively. Optimal power allocation schemes that maximize system capacity with AF strategy are presented. In addition, optimal power allocation methods that minimize asymptotic Symbol Error Rate (SER) with SDF cooperative protocol in multi-node scenario are also proposed. Furthermore, performance comparisons are provided in terms of system capacity and approximate SER. Numerical and simulation results confirm our theoretical analysis. It is revealed that, maximum system capacity could be obtained when powers are allocated optimally with AF protocol, while minimization of system's SER could also be achieved with optimum power allocation in SDF strategy. In multi-node scenario, those optimal power allocation algorithms are superior to conventional equal power allocation schemes.

计及电-碳交易与综合贡献率的多微网合作运行优化策略

多微网协同互联能够提高系统运行的稳定性与可靠性。针对多微网(multi-microgrids,MMG)系统合作运行过程中由于各微网分属于不同的利益主体而产生的微电网之间的电能交易问题、碳交易问题与利益分配问题,提出一种计及电-碳交易与综合贡献率的多微网合作运行优化策略。首先,分析了含点对点(peer-to-peer,P2P)电-碳交易的多微网合作运行架构,并引入碳捕集系统(carbon capture system,CCS)与电转气(power to gas,P2G)装置,建立了微电网系统及设备模型。其次,在单微网模型构建之后,基于纳什议价理论,构建了含P2P电-碳交易的多微网系统合作运行模型,并将非凸非线性的纳什议价问题转化为易于求解的MMG合作成本最小化与支付收益最大化两个子问题。然后,在合作后的利益分配过程中,量化各微电网对MMG的综合贡献程度并计算出各自的综合贡献率,通过综合贡献率来分配各微网的收益。最后,采用交替方向乘子法(alternating direction multiplier method,ADMM)求解,有效保护了各微网隐私。算例分析与方案对比结果表明,所提策略能够实现微网间的P2P电-碳交易,有效降低MMG总运行成本,减少系统的碳排放量,并且采用的利益分配策略公平合理,能够有效提升各微网参与合作运行的积极性。

无线紫外光与射频混合链路中继协作方案性能分析

将无线紫外光通信与传统射频通信进行优势互补结合,针对双链路异构组网时的中继协作混合传输问题,采用建模与数值计算分析的方法,对比分析了不同策略和参数条件下系统的中断概率和误码率性能。基于无线紫外非直视散射信道和射频无线衰落信道的各自特点,建立了描述双链路并行传输中继与协作问题的模型,给出了3种典型情况下的传输策略。通过理论分析和数值计算的方法,给出了不同策略下混合链路中继的中断概率和误码率表达式,并在不同信道参数条件下对系统性能进行了对比分析。研究结果表明,相比于无线紫外光单链路传输,混合链路的中继协作策略在不同距离和不同参量条件下获得更低的系统中断概率。在误码率为1×10^(-6)条件下,双链路中继传输可以在不同湍流强度和不同莱斯因子情况下可获得约0.4~6.1 dB的信噪比增益改善。

非理想干扰消除全双工协作NOMA系统性能分析及功率分配

随着非正交多址接入(Non-Orthogonal Multiple Access,NOMA)技术的不断发展,协作NOMA(Cooperative Non-Orthogonal Multiple Access,CNOMA)也受到广泛关注.该文研究了由一个基站(Base Station,BS)、一个远端用户和一个近端用户组成的全双工(Full-Duplex,FD)协作NOMA(FD-CNOMA)系统,其中近端用户作为一个FD解码转发中继以传输远端用户的信号.考虑实际情况中存在基站与远端用户有无直接链路两种情况,以及非理想连续干扰消除(Successive Interference Cancellation,SIC)对系统带来的残留干扰问题,该文提出并解决了在该模型下用户的功率分配问题.最后,该文基于此模型给出了中继用户和远端用户的中断概率闭式表达式和遍历速率的近似闭式表达式.理论分析与仿真结果表明,即便存在非理想SIC和自干扰,相对于半双工(Half-Duplex,HD)协作NOMA(HDCNOMA)和NOMA系统而言,FD-CNOMA系统表现出更好的系统性能.同时,非理想SIC和中继用户自干扰都会对用户性能产生负面影响,且非理想SIC在遍历速率上对HD机制的影响较FD机制更为严重.最后,文中提出的功率分配方法较随机功率分配和固定功率分配分别获得了13%和10%的速率提升.

城乡基本医疗保险制度实施对家庭消费的影响效应及作用机制

基于1988—2018年中国家庭收入调查数据,以城乡基本医疗保险制度实施为准自然实验,采用双重差分法考察了城镇基本医疗保险与新型农村合作医疗保险(即新农合)对家庭消费率的影响及其机制。结果显示:相较于未参保家庭,参加城镇医保的家庭消费率显著高出1.01%,但新农合的影响不显著;机制分析发现,城镇医保促进了参保家庭的总消费和分项消费支出,但新农合对消费支出无显著影响,同时,城镇医保和新农合对总收入和大部分分项收入无显著影响,这与基准回归结果一致;异质性分析表明,城镇医保更多地提升了中老年、非富裕、不健康群体,以及西部地区的家庭消费率。对此,应当充分发挥基本医疗保险制度对提振家庭消费率的积极作用,对“大水漫灌”式的财政补助应进行反思;改变基本医保“户保分离”“业保分离”的现状;加强针对特定人群的医保政策;注重提高参保青年和健康群体的获得感。

战略合作框架协议对股票收益率的影响——基于沪深A股市场的实证分析

战略合作框架协议近些年愈发受到上市公司的关注,但对其市场的影响尚未有明确结论。本文以2004~2022年沪深股市发布的2948份战略合作框架协议为研究样本,采用事件研究方法构建计量模型估计协议对发布公司股票市场表现的影响。结果表明:(1)在协议发布的不同事件窗口期,发布公司股票总体取得显著为正的累积特异收益率,且随与协议发布时点的间隔呈倒U形状;(2)协议的影响具有公司规模和交易对象差异性,小市值公司、交易对象同为企业的公司获得更高累积特异收益率;(3)协议内容与行业类型产生交互影响,从事公用事业的公司获得更高累积特异收益率,产业链协调、项目建设开发、股权投融资领域的协议因行业不同带来差异化的累积特异收益率。研究结论揭示了战略合作框架协议对发布公司股票市场表现的规律性特征,为投资者和上市公司提供借鉴。

无人机辅助无线通信网络资源自适应协同分配

为保证边缘用户可正常使用通信网络资源,研究了无人机辅助的无线通信网络资源自适应协同分配技术。构建无人机辅助无线通信网络模型,并设置自适应协同分配的目标函数,从而进行网络资源最大化的资源分配。引入排斥、吸引方法改进果蝇算法,提取最优、最差味道浓度与坐标信息。输出资源的最优传输速率、最优无人机运行轨迹的分配解,改进求解资源分配目标函数,完成通信网络资源自适应协同分配。试验结果表明,不同工况中,无人机能够结合用户分布状态飞行。在用户最小速率需求标准依次是3 bit/s、6 bit/s、9 bit/s时,经过6次迭代,算法便可收敛到纳什均衡点,无线通信任务时延便可控制为最小值1.5 s。该技术能够自适应协同分配无人机辅助无线通信网络资源。协同分配结果满足用户需求。

多学科合作吞咽模式干预对帕金森病吞咽障碍患者吞咽功能及误吸率的影响

目的探究多学科合作吞咽模式干预对帕金森病吞咽障碍患者吞咽功能及误吸率的影响。方法纳入2019-12—2022-10于南京医科大学第一附属医院接受多学科合作的吞咽模式干预的40例帕金森病吞咽障碍患者为研究组,另纳入同期接受常规护理的40例帕金森病吞咽障碍患者为对照组。干预6个月后,比较2组患者吞咽功能、生活质量、误吸率、肺炎发生率及胃管留置率。结果干预6个月后,2组患者洼田饮水试验评级均较干预前低,且研究组低于对照组(P<0.05);2组患者Gugging吞咽功能评估量表(GUSS)评分均较干预前高,且研究组高于对照组(P<0.05);2组患者干预后生活质量综合评定问卷(GQOLI-74)各维度评分均高于干预前,研究组除躯体功能维度外均高于对照组(P<0.05)。干预3个月后,研究组误吸率22.50%,对照组为40.00%,差异无统计学意义(P>0.05),干预6个月后,研究组误吸率5.00%,对照组为22.50%,差异有统计学意义(P<0.05)。干预6个月后,研究组肺炎发生率为5.00%,对照组为25.00%,差异有统计学意义(P<0.05);研究组胃管留置率为5.00%,对照组为27.50%,差异有统计学意义(P<0.05)。结论多学科合作的吞咽模式干预可有效改善帕金森病患者吞咽功能障碍,降低误吸率、肺炎发生率以及胃管留置率,具有较高的安全性。

基于改善率统计的MAPF-LNS2+算法

MAPF-LNS2是一种基于大邻域搜索的算法,用于解决多智能体路径规划问题。优势在于其速度更快,在大多数情况下提供接近最优解的解决方案。但该算法在分配权重时仅考虑当前邻域搜索策略的近期表现并有可能分配了较高的权重,使其他邻域搜索策略出现短暂的“饥饿”现象,导致增加算法的总运行时间。针对该问题基于MAPF-LNS2算法,通过引入改善率统计和时间窗口提出了一种新的多智能体路径规划算法。结果表明,无论是在运行时长还是成功率方面,MAPF-LNS2+算法均优于MAPF-LNS2算法,运行时间最高降低了65.1%,成功率最大提升了16%。

注二氧化碳驱替稠油技术研究进展

稠油具有黏度大、流动性差等特点,导致开采难度增大、采收率降低等问题出现。目前,注二氧化碳驱替稠油技术已在各大油田得到广泛应用,取得了一定效果,但实际应用与未来发展也面临一定挑战。驱油机理方面,二氧化碳可用于稠油开采,主要通过降黏、溶解等作用增强稠油的流动性。驱替技术方面,二氧化碳驱替稠油开采技术按介质个数可以分为一元驱替、二元复合驱替、三元协同驱替。二氧化碳吞吐技术是驱替普通稠油的主要方式;非均质性较强的特稠油、超稠油,需加入蒸汽、化学试剂等物质综合作用;“CO_(2)+”多元介质复合驱替技术是未来的发展趋势。实践效果方面,二氧化碳辅助三元协同驱替稠油技术采收率最高。二氧化碳辅助驱替稠油技术主要应用于普通稠油油藏,未来应在深层超稠油开采的适应性、二氧化碳埋存等方面加强理论研究和先导试验。

具有未知增长率的一类上三角非线性多智能体系统的协同控制

基于有向领导者-追随者型的网络拓扑结构,研究了一类具有未知增长率的上三角非线性多智能体系统的协同控制问题。首先,通过引入坐标变换,将原系统转换为带有时间增益的等效系统;其次,针对标称系统进行控制器设计,获得原系统的分布式时变状态反馈控制器。所设计的控制器能够保证追随者与领导者的输出跟踪误差有界,且闭环系统所有信号有界。最后,利用仿真实例验证了控制方案的有效性。

良好护理配合对腹腔镜下直肠癌根治术患者手术成功率及并发症的影响

目的 分析在腹腔镜下直肠癌根治术治疗中良好护理配合对患者手术成功率及并发症的影响。方法 选取2021年1月—2023年1月本院收治的120例直肠癌患者为研究对象,并按照随机数字表法分为观察组(良好护理配合,60例)、对照组(常规护理,60例),对比分析护理后两组患者对护理的满意度、手术成功率、并发症发生率(肠梗阻、输尿管受损、感染)、手术指标(手术时间、术中出血量、肠道恢复时间、住院时间)。结果 护理后,观察组护理满意度、手术成功率高于对照组,手术时间、肠道恢复时间、住院时间短于对照组,术中出血量与并发症发生率低于对照组,对比差异有统计学意义(P<0.05)。结论 在腹腔镜下直肠癌根治术治疗中良好的护理配合能够明显提高手术治疗成功率,缩短手术时间与恢复时间,患者对护理的满意度更高,术后并发症发生率较常规护理更低,有利于促进治疗后康复,值得推广。

近距离煤层及上覆煤柱协同开采技术实践

封闭煤层的开采会保留大量总宽度为30~40 m的断面煤柱,造成了煤炭资源的巨大浪费,并存在自燃、失稳和破坏剩余煤柱的风险。通过数值模拟,研究了下煤层巷道与上覆煤柱水平距离(即间距)对巷道围岩控制和合理布置的影响,分析了上覆煤柱宽度对采场地压和煤柱回采率影响的机理。东周窑煤业公司的实践表明,当水平间距由0 m增大到15 m时,巷道围岩变形量、围岩应力峰值、塑性区面积均显著减小;当上覆段煤柱宽度由25 m增加到40 m时,采场横向应力峰值和超前轴承应力峰值分别下降21 MPa和12 MPa,采场地压驱动强度显著降低,煤层间覆岩和煤柱回收率分别提高7.45%和4.29%。结合顶柱放煤方式,提出了优化的概念和实现方法。