Proportional Fairness-Based Energy-Efficient Power Allocation in Downlink MIMO-NOMA Systems with Statistical CSI

In this paper, proportional fairness(PF)-based energy-efficient power allocation is studied for multiple-input multiple-output(MIMO) non-orthogonal multiple access(NOMA) systems. In our schemes, statistical channel state information(CSI) is utilized for perfect CSI is impossible to achieve in practice. PF is used to balance the transmission efficiency and user fairness. Energy efficiency(EE) is formulated under basic data rate requirements and maximum transmitting power constraints. Due to the non-convex nature of EE, a two-step algorithm is proposed to obtain sub-optimal solution with a low complexity. Firstly, power allocation is determined by golden section search for fixed power. Secondly total transmitting power is determined by fractional programming method in the feasible regions. Compared to the performance of MIMO-NOMA without PF constraint, fairness is obtained at expense of decreasing of EE.

Proportional Fairness Based Energy Efficient Routing in Wireless Sensor Network

Wireless Sensor Network (WSN) is an independent device that comprises a discrete collection of Sensor Nodes (SN) to sense environmental positions,device monitoring, and collection of information. Due to limited energy resourcesavailable at SN, the primary issue is to present an energy-efficient framework andconserve the energy while constructing a route path along with each sensor node.However, many energy-efficient techniques focused drastically on energy harvesting and reduced energy consumption but failed to support energy-efficient routingwith minimal energy consumption in WSN. This paper presents an energy-efficientrouting system called Energy-aware Proportional Fairness Multi-user Routing(EPFMR) framework in WSN. EPFMR is deployed in the WSN environment usingthe instance time. The request time sent for the route discovery is the foremost stepdesigned in the EPFMR framework to reduce the energy consumption rate. Theproportional fairness routing in WSN selects the best route path for the packet flowbased on the relationship between the periods of requests between different SN.Route path discovered for packet flow also measure energy on multi-user route pathusing the Greedy Instance Fair Method (GIFM). The GIFM in EPFMR developsnode dependent energy-efficient localized route path, improving the throughput.The energy-aware framework maximizes the throughput rate and performs experimental evaluation on factors such as energy consumption rate during routing,Throughput, RST, node density and average energy per packet in WSN. The RouteSearching Time (RST) is reduced using the Boltzmann Distribution (BD), and as aresult, the energy is minimized on multi-user WSN. Finally, GIFM applies aninstance time difference-based route searching on WSN to attain an optimal energyminimization system. Experimental analysis shows that the EPFMR framework canreduce the RST by 23.47% and improve the throughput by 6.79% compared withthe state-of-the-art works.

User Fairness Scheme with Proportional Fair Scheduling in Multi-user MIMO Limited Feedback System

In Multi-user MIMO (MU-MIMO) downlink system, suitable user selection schemes can improve spatial diversity gain. In most of previous studies, it is always assumed that the base station (BS) knows full channel state information (CSI) of each user, which does not consider the reality. However, there are only limited feedback bits in real system. Besides, user fairness is often ignored in most of current user selection schemes. To discuss the user fairness and limited feedback, in this paper, the user selection scheme with limited feedback bits is proposed. The BS utilizes codebook precoding transmitting strategy with LTE codebook. Furthermore, this paper analyzes the influence of the number of feedback bits and the number of users on user fairness and system sum capacity. Simulation results show that in order to achieve better user fairness, we can use fewer bits for feedback CSI when the number of user is small, and more feedback bits when the number of users is large.

Resource Allocation for OFDMA-MIMO Relay Systems with Proportional Fairness Constraints

In this paper, we study resource allocation problem in orthogonal frequency division multiple access multiple-input multiple-output (OFDMA-MIMO) relay systems and formulate the optimal instantaneous resource allocation problem including subcarrier assignment, relay selection and power allocation to maximize system capacity. Based on the assumption that the availability of perfect channel state information (CSI) is known at the resource allocation controller, we propose a new resource allocation algorithm which can guarantee proportional fairness among users. In the proposed algorithm, a two-step suboptimal method is taken into account. Firstly, we assume equal power allocation for each user to linearize the problem and propose the subcarrier assignment and relay selection scheme based on equivalent channel gain. Secondly, we derive the closed-form expressions for power allocation through relaxing the proportional fairness constraints. Numerical simulations show that the proposed algorithm performs well in terms of satisfying proportional fairness among users in strict sense and achieving improvement on system total capacity.

FMAC: Fair Mac Protocol for Achieving Proportional Fairness in Multi-Rate WSNs

In a multi-rate wireless environment, slow nodes occupy the channel for longer time than fast nodes and thus the total throughput of the network will be reduced. In this research, we study the problem of fairness in multi-rate wireless sensor networks. To improve the fairness, we propose a new protocol, FMAC (Fair MAC protocol) that is based on IEEE 802.11 MAC protocol to achieve proportional fairness between all nodes. FMAC protocol includes medium delay periods within Backoff algorithm to utilize the idle slots of time and reduce the number of collisions and then number of retransmissions, and thus reducing the energy consumption, which is very critical in wireless sensor networks. The experimental results show that transmissions become faster with less collisions and power consumption when applying FMAC, while the aggregated throughput and proportional fairness are increased. The detailed performance evaluation and comparisons are provided using the simulation.

Fairness Aware Rate Adaptation and Proportional Scheduling for IEEE 802.11 WLANs Using FSE

With its rapid development in the wireless markets, IEEE 802.11 WLAN is experiencing a huge popularity. However, due to the limitation of frequency bandwidth of WLANs, it is essential that the available radio resource should be fully utilized to offer different services to multiple users. In order to maximize system throughput while still guaranteeing the fairness among users, a proportional fairness based algorithm is proposed in this work. Since most of the previous resource allocation algorithms were simply based on the channel conditions without taking into account user's demand, in this paper, we introduce the theory of fuzzy synthetic evaluation(FSE) which also allows us to consider user's demand as an important factor. As such, the fairness among users can be improved based on different users' requirements for services. In addition, a channel state information based rate adaptation scheme is also proposed. Through simulation studies, the results clearly validate that our proposed scheme shows advantages on providing user fairness while still improving the system throughput.

QoE-Aware Proportional Fair Scheduling for Multiuser Multiservice Wireless Networks

The effective radio resource allocation algorithms,which satisfy diversiform requirements of mobile multimedia services in wireless cellular networks,have recently attracted more and more attention.This paper proposes a service-aware scheduling algorithm,in which the Mean Opinion Score (MOS) is chosen as the unified metric of the Quality of Experience (QoE).As the network needs to provide satisfactory services to all the users,the fairness of QoE should be considered.The Proportional Fair (PF) principle is adopted to achieve the trade-off between the network performance and user fairness.Then,an integer programming problem is formed and the QoE-aware PF scheduling principle is derived by solving the relaxed problem.Simulation results show that the proposed scheduling principle can perform better in terms of user fairness than the previous principle maximizing the sum of MOS.It also outperforms the max-min scheduling principle in terms of average MOS.

DISTRIBUTED PROPORTIONAL FAIR FREQUENCY ALLOCATION ACROSS MULTIPLE BASE STATIONS

The problem of distributed proportional fair inter-cell frequency allocation for flat-structured cellular systems is studied in this paper. We firstly propose a framework of the frequency allocation in which the whole frequency allocation process is decomposed into many consecutive stages, then identify that for each stage the key is to find the Maximum Weight Independent Set (MWIS) in a given weighted conflict graph in the distributed manner. A new distributed algorithm for MWIS is described in which each node iteratively exchanges messages with neighbors. With this distributed MWIS algorithm, a new distributed proportional fair frequency allocation scheme is presented. The performance of the proposed algorithm is tested in computer experiments simulating the Long Term Evolution (LTE) cellular systems. Simulation results show the performance of the proposed distributed proportional fair frequency allocation scheme is comparable with the centralized ones.

A New Fairness-Oriented Packet Scheduling Scheme with Reduced Channel Feedback for OFDMA Packet Radio Systems

In this paper, we propose a flexible and fairness-oriented packet scheduling approach for 3GPP UTRAN long term evolution (LTE) type packet radio systems, building on the ordinary proportional fair (PF) scheduling principle and channel quality indicator (CQI) feedback. Special emphasis is also put on practical feedback reporting mechanisms, including the effects of mobile measurement and estimation errors, reporting delays, and CQI quantization and compression. The performance of the overall scheduling and feedback re-porting process is investigated in details, in terms of cell throughput, coverage and resource allocation fairness, by using extensive quasistatic cellular system simulations in practical OFDMA system environment with frequency reuse of 1. The performance simulations show that by using the proposed modified PF ap-proach, significant coverage improvements in the order of 50% can be obtained at the expense of only 10-15% throughput loss, for all reduced feedback reporting schemes. This reflects highly improved fairness in the radio resource management (RRM) compared to other existing schedulers, without essentially com-promising the cell capacity. Furthermore, we demonstrate the improved functionality increase in radio re-source management for UE’s utilizing multi-antenna diversity receivers.

豆胶/PF的混合应用

研究了化学改性豆胶加入酚醛(PF)树脂交联剂后提高胶合板强度的问题。利用石灰乳、氢氧化钠、硅酸钠等化学药剂按不同配制比例对豆粉进行改性,制备豆胶;按胶合强度筛选出的最优配方,以达到Ⅲ类胶合板的强度要求。将改性豆胶与PF胶按3∶1的比例混合应用,在150℃温度、2.5MPa压力、5min热压时间条件下压制的胶合板可以达到Ⅰ类胶合板的强度要求。PF胶以适当的比例添加才能起到良好的交联作用。豆胶与PF的混合应用使胶合板的强度和耐水性得到极大改善,为开发利用低成本高性能天然胶黏剂做出了有益的探索。

改进权值计算的EPF算法及在目标跟踪中的应用

扩展卡尔曼粒子滤波(EPF)在预测阶段通过EKF选取重要性函数而优化了粒子选取,但是传统EPF算法中粒子权值一般是通过正态分布的概率密度函数计算的。此方法没有突出不同噪声粒子的权值差别,在计算中引入了较大的相对误差。通过在更新阶段对权值计算所依赖的概率密度函数做出改进,得到改进的EPF算法。同时采用实际目标跟踪数据进行仿真对比实验,结果验证了此方法有效可行,并且减小了预测误差。

PFWRR：能实现比例公平的增强型WRR

为了实现比例公平原则,在加权轮循调度(WRR)算法的基础上提出了比例公平WRR调度算法——PFWRR.PFWRR依据各队列的平均分组到达率,调整各队列的调度权值,从而在当队列长度小于等于缓冲长度时,保证各队列的平均分组排队时延符合给定比例;当队列长度大于缓冲时,保证各队列的平均分组丢失率符合给定比例.PFWRR的计算负荷是合理的,因为它仅当系统超载且平均分组到达率发生变化时,才调整各队列的服务率.实测性能显示:当系统超载且不出现分组丢失时,PFWRR实现了比例平均分组排队时延保证,当系统出现分组丢失时,PFWRR实现了比例平均分组丢失率保证.

PFS在分布式移动通信系统中的应用研究

为提高分布式移动通信系统的空间资源利用率，在并行调度思想的指导下，提出了并行比例公平调度（PPFS）方法，该方法可在取得多用户分集增益的基础上取得复用增益，进一步提高了系统的吞吐量。仿真结果表明，在分布式移动通信系统中，PPFS不仅能够为用户提供更多的接入机会，获得更高的平均系统吞吐量，并且较好地继承了比例公平调度（PFS）算法的良好的公平性性能。

1xEV-DO Rev A中PF调度算法的实现

分析1xEV-DO Rev A中PDMA等技术对PF调度算法的影响,给出算法的具体实现方法,通过仿真实验研究其性能。实验结果表明,包分复用、HARQ等技术的引入可以使PF算法在1xEV-DO Rev A中获得较好的前向链路吞吐率,更好地满足实时业务的延迟需求。

锈红色清水混凝土的质量控制及施工技术研究

以杭钢旧址公园工程为研究背景,从原材料选择、配合比设计、模板工程、施工工艺等方面探讨了锈红色清水混凝土的质量控制及关键施工技术,为推动彩色清水混凝土施工技术的发展提供了有益借鉴和指导。

LTE-A系统载波聚合情况下改进的PF算法

为提高边缘用户的吞吐量和用户间的公平性,提出了边缘用户优先比例公平算法。算法思想是让某些成分载波上的RBs以概率a分配给边缘用户,以概率1-a分配给中心用户,分配后再使用传统的比例公平算法进行调度;而其他成分载波上的RBs直接使用传统的比例公平算法进行调度。仿真表明,该算法可以较好地提高边缘用户的吞吐量和用户间的公平性,并且可以通过控制a的大小来调节边缘用户吞吐量和用户间的公平性。

The proportional fairness scheduling algorithm on multi-classes

In this paper, we study resource management models and algorithms that satisfy multiple performance objects simultaneously. We realize the proportional fairness principle based QoS model, which defines both delay and loss rate requirements of a class, to include fairness, which is important for the integration of multiple service classes. The resulting Proportional Fairness Scheduling model formalizes the goals of the network performance, user’s QoS requirement and system fairness and exposes the fundamental tradeoffs between these goals. In particular, it is difficult to simultaneously provide these objects. We propose a novel scheduling algorithm called Proportional Fairness Scheduling (PFS) that approximates the model closely and efficiently. We have implemented the PFS scheduling in Linux. By performing simulation and measurement experiments, we evaluate the delay and loss rate proportional fairness of PFS, and determine the computation overhead.

Resource Allocation in UAV-NOMA Communication Systems Based on Proportional Fairness

This paper investigates the power allocation problem in non-orthogonal multiple access(NOMA)integrated unmanned aerial vehicle(UAV)communication systems.In particular,we propose a novel resource allocation scheme to increase the transmission rate of the users that have relatively worse channel state information,while reducing the sum rate loss.To solve this problem efficiently,we decouple the optimization problem into three subproblems.First,we solve the problem of user pairing and subchannel allocation.Second,the optimum power proportional factor is derived to allocate transmit power among different users on the same subchannel.At last,different subchannels are allocated with appropriate power to improve the performance of the subchannels.Simulation results show that the proposed scheme can enjoy a better performance than the benchmark methods since it can achieve a proper trade-off between the system sum rate and the proportional fairness.

基于联合优化的网络切片资源分配策略

为解决5G网络中各类应用差异性大对通信需求侧重点不同造成的网络资源利用率低的问题,提出一种基于联合优化的网络切片资源分配策略,旨在通过综合考虑切片间资源分配和切片内资源调度问题,最大化网络资源利用率和网络收益。首先,在切片间资源分配问题中定义一个切片用户平均满意度函数,基于切片用户数量、切片调度时延以及切片优先级等约束,提出基于用户服务质量(Qo S)的比例公平资源分配算法,以权衡各切片之间的公平性和用户需求。其次,在切片内资源调度问题中引入服务降级和资源迁移函数,针对拥塞和非拥塞2种情况为内部接入用户和外部接入用户分别建立价格模型。基于所提价格模型建立基站与用户之间的Stackelberg博弈,并采用一种低复杂度的全局搜索算法求解该博弈的最佳响应,使基站效用和用户效用最优。仿真结果表明,所提策略能够有效提高资源利用率和网络收益,并降低网络拥塞,较好地实现资源分配的公平性。

多层次医疗保障筹资的理论逻辑及实现路径

在差异性社会情境下,医疗保障在筹资端的“条件-环境”的非一致性使得我们需要“重塑”医疗保障筹资的理论逻辑及探寻更加可持续性的实现路径。医疗保障的筹资应从结构功能主义视角切入,遵循基于“底线公平+正比公平+效率正义”的“多层结构”原则。中国医疗保障政策治理需要走向“先整合,后统筹”的发展优化路径,即“财政预算+社会供款+风险筹资”的多元协同供给模式。保障底线公平,体现权益公平,尊重正比公平,使医疗保障的筹资体系更多地体现为维护国民健康权益的第一端口。在系统性治理体制与机制下最终探索出一条基于“底线-权益-差异”公平正义的医疗保障筹资的实现路径,使得医疗保障筹资逻辑最终实现从差异性逻辑走向权责共同体逻辑。