一种基于新一代蜂窝移动通信的无线资源分配方案

新一代的蜂窝移动通信系统要求支持多种业务,从高质量的交互式实时业务到基于TCP连接的完全可靠服务。对于现有的无线链路,用户各种业务量的增加造成无线资源相对使用不平衡,大大降低了无线网络的吞吐量。本文提出了一种基于新一代蜂窝通信的无线资源分配方案,并利用OPNET建立仿真平台对该方案进行验证。仿真结果表明,各种不同优先等级的业务都能得到自己满意的服务质量,链路总的吞吐量达到了1 0 0 Mbit/s     

一种适用于B3G移动通信系统下行共享信道的调度算法

本文针对后三代(B3G)移动通信系统中的宽带无线信道特性和流媒体业务特征,分析了可用于高速下行共享信道的各种传统分组调度算法,提出面向流媒体业务能够提高系统吞吐量的基于优先级公平调度(Priority-Based Fairness Scheduling,PBFS)算法.该算法根据各移动用户收发信道质量和业务传输的QoS要求动态调整各用户的业务传输优先级,确定下行共享信道的调度方案.并给出该算法的简化形式S-PBFS.仿真结果表明,与传统调度算法相比,S-PBFS算法在数据包传输时延受限的条件下具有无线信道利用率高、实现复杂度低等特点.     

正交频分多址系统中一种面向多业务应用的自适应资源分配算法

针对正交频分多址(OFDMA)系统下行链路多业务自适应调度的问题,该文首先以最大化系统吞吐量为优化目标、每种业务的服务质量(QoS)保证为约束条件,建立了一种通用的多业务自适应资源分配模型。为解决此优化问题,提出了一种具体的自适应资源调度算法。该算法对实时业务按照用户选择最好的信道的原则分配尽可能少的资源以保证其QoS,对非实时业务把尽可能多的剩余资源按照信道选择最好的用户的原则进行分配,充分利用信道资源,提升系统容量。仿真结果表明,该算法保证了下行OFDMA系统吞吐量的同时,在实时业务的延时和丢包率等方面有一定的优越性。     

HSDPA系统中一种感知用户终端缓存状态的QoE保障调度算法

针对HSDPA系统中现有调度算法无法满足实时业务QoE的缺点,提出一种保障实时业务QoE的调度算法。该算法根据用户反馈的信道质量信息和在基站获取到的用户终端缓存状况信息。确定用户的优先级并据此调度优先级最高的用户,进而保证实时业务的吞吐量和QoE需求。仿真结果表明,与轮询调度算法、比例公平调度算法相比,提出的调度算法不仅能够保证实时业务的QoE需求,而且能满足非实时业务基本的吞吐量需求。     

一种具有QoS保证的无线分组调度算法

为提高系统吞吐量对指数规则（EXP-rule）调度算法进行了改进。改进的指数规则（WEXP-rule）算法根据各移动用户收发信道质量和业务传输的QoS要求动态调整各用户的业务传输优先级,确定下行共享信道的调度方案。并给出该算法的简化形式SWEXP-rule。仿真结果表明,与传统调度算法相比,SWEXP-rule算法在数据包传输时延受限的条件下具有无线信道利用率高、实现复杂度低等特点。     

HSDPA分组调度算法在吞吐量方面的仿真分析

文章首先对基于非实时业务无线分组调度算法进行了分析，然后对各种算法在吞吐量方面进行了仿真，仿真分析表明：在不同的仿真时间里，MAX C／I获得了最大的扇区平均吞吐量：而RR算法未考虑用户当前的无线环境，吞吐量最小。     

802.16e系统非实时业务的无线资源调度算法

本文介绍了802.16e系统非实时业务的几种资源调度算法和SCGNF规则。通过仿真,分析了各种算法和SCGNF规则在吞吐量和溢出率方面的性能表现。     

HSDPA中M-LWDF实时业务分组调度算法的改进

HSDPA是UMTS的最新演进。HSDPA采用先进的技术包括AMC、HARQ和快速小区选择以提供更高的数据速率。在HSDPA系统中,无线资源管理功能主要是由分组调度算法来实现,研究先进的分组调度算法是提高数据业务吞吐量、保证用户间的公平性、满足业务QoS的根本。主要介绍了实时业务算法M-LWDF,针对其在公平性方面的缺陷进行了改进,并对上述2种算法在中断率和吞吐量上进行了试验分析。     

一种适用于CoMP的改进MaxC/I算法

Max C/I算法是LTE中一种常见的资源调度算法,致力于实现吞吐量的最大化。在非Co MP场景下将总吞吐量最大化的目标分解到各小区,使每个小区吞吐量最大,用此解法求得的解是全局最优解。但如果将这种解法直接引入到LTE-A的Co MP场景下使用时,协作小区间的调度结果可能会相互影响,最终得到的解是贪婪解,而且该贪婪解不太理想,不能发挥出Max C/I算法的性能。针对此问题,将原解法的子问题决策进行改进,对是否调度Co MP用户增加了条件判断,并在Full Buffer业务模型和FTP业务模型下进行仿真验证,结果表明该改进方案能在一定程度上提高系统吞吐量。     

适用ROF无线通信系统的调度算法

提出了一种基于多业务的提供QOS保证的调度算法,主要应用在使用ROF技术的多媒体无线通信系统中。该算法是在研究Q-PFS算法的基础上,分析了ROF技术和多媒体无线通信的特点后提出的。算法解决了多业务情况下的无线资源的调度问题,实现吞吐量的最大化和各业务之间的公平性,同时保证了QOS。     

Traffic Aided Uplink Opportunistic Scheduling with QoS Support in Multiservice CDMA Networks

In this letter, we address the problem of resource allocation with efficiency and quality of service (QoS) support in uplink for a wireless CDMA network supporting real‐time (RT) and non‐realtime (NRT) communication services. For RT and NRT users, there are different QoS requirements. We introduce and describe a new scheme, namely, traffic aided uplink opportunistic scheduling (TAUOS). While guaranteeing the different QoS requirements, TAUOS exploits the channel condition to improve system throughput. In TAUOS, the cross‐layer information, file size information, is used to improve fairness for NRT users. Extensive simulation results show that our scheme can achieve high system throughput in uplink wireless CDMA systems, while guaranteeing QoS requirements.     

CDMA2000 1xEV-DO中的分组调度算法

移动通信系统需要更好地支持分组数据业务，并满足高速分组数据业务的服务质置要求。这可以通过采用好的调度算法提高平均业务速率和系统整体稳定性实现。针对CDMA2000 1x EV-DO系统的有代表性的调度算法有3种：正比公平算法、速率受限的最大载干比算法、加权公平排队-正比公平（WFQ-PF）联合算法。正比公平调度算法是一种算法简单实用的调度方案，但不能满足用户的服务质景保证；速率受限的最大载干比算法具有比正比公平算法更高的平均吞吐量，可方便地在吞吐量和公平性之间获得很好的折衷；WFQ-PF联合算法具有良好的综合性能，但算法较复杂。     

Resource Allocation for Real Time Services in LTE Networks: Resource Allocation Using Cooperative Game Theory and Virtual Token Mechanism

The LTE specifications provide QoS for multimedia services with fast connectivity, high mobility and security. However, 3GPP specifications have not defined scheduling algorithms to exploit the LTE characteristics to support real time services. In this article we propose a two level scheduling scheme composed by cooperative game theory, a virtual token mechanism, and the well known algorithms EXP-RULE and Modified-Largest Weighted Delay Firs (M-LWDF) in downlink system. By using cooperative game theory such as bankruptcy game and Shapley value, the proposed mechanism works by forming coalitions between flow classes to distribute the bandwidth fairly among all of them. Both algorithms EXP-RULE and M-LWDF have been modified to use a virtual token mechanism to improve their performance, giving priority to real time flows. By taking the arrival rate of packets into account, the proposed mechanism partially included in previous schedulers has been adapted to this work to increase remarkably the performance of the resource allocation for real time flows. The performance evaluation is conducted in terms of system throughput, Packet loss ratio, total cell spectral efficiency, delay and fairness index.     

Resource scheduling scheme with QoS support in two-hop relay-enhanced OFDMA systems

As the system performance is obviously improved by introducing the concept of relay into the traditional orthogonal frequency division multiple access(OFDMA)systems,resource scheduling in relay-enhanced OFDMA systems is worthy of being studied carefully.To solve the optimization problem of achieving the maximum throughput while satisfying the quality of service(QoS)and guaranteeing the fairness of users,a novel resource scheduling scheme with QoS support for the downlink of two-hop relay-enhanced OFDMA systems is proposed.The proposed scheme,which is considered both in the first time sub-slot between direct link users and relay stations,and the second time sub-slot among relay link users,takes QoS support into consideration,as well as the system throughput and the fairness for users.Simulation results show that the proposed scheme has good performance in maximizing system throughput and guaranteeing the performance in the service delay and the data loss rate.     

基于满意度准则采用混合波束成型预编码的调度方法

为了满足未来无线宽带网络中多种服务质量(QoS)要求业务并存的需求,该文提出一种多天线下行系统中结合混合波束成型预编码技术基于满意度的调度方法。该调度方法联合考虑用户的QoS要求及其信道质量,灵活地使用随机波束成型和迫零波束成型预编码技术,并通过惩罚机制避免特定用户占用超出其需求的带宽,更有效地为用户分配令其满意的资源,使各种QoS要求的用户获得满意的服务。仿真结果证明,与现有的方法相比,该文提出的方法在保证用户服务质量的同时,能更好地利用系统资源。     

Buffer-aware resource scheduling scheme for LTE-A uplink relay-assisted network

Due to the constraint of single carrier frequency division multiple access （SC-FDMA） adopted in long term evolution （LTE） uplink, subcarriers allocated to single user equipment （UE） must be contiguous. This contiguous allocation constraint limits resource allocation flexibility and makes the resource scheduling problem more complex. Most of the existing work cannot well meet UE＇s quality of service （QoS） requirement, because they just try to improve system performance mainly based on channel condition or buffer size. This paper proposes a novel resource scheduling scheme considering channel condition, buffer size and packet delay when allocating frequency resource. Firstly, optimization function is formulated, which aims to minimize sum of weight for bits still left in UE buffer after each scheduling slot. QoS is the main concern factor here. Then, to get packet delay information, this paper proposes a delay estimation algorithm. Relay node （RN） is introduced to improve overall channel condition. Specific RN selection strategy is also depicted in the scheme. Most important of all, a creative negotiation mechanism is included in the subcarrier allocation process. It can improve the overall system throughput performance in guarantee of user＇s QoS requirement. Simulation results demonstrate that the scheme can greatly enhance system performance like delay, throughput and jitter.     

Scheduling schemes for multimedia service in wireless OFDM systems

Scheduling schemes play a key role in the system performance of broadband wireless systems such as WLANs/WMANs. Maximal SNR and round robin are two conventional scheduling strategies that emphasize efficiency and fairness, respectively. The proportional fair scheme provides a trade-off between efficiency and fairness, and has been well studied in TDMA and CDMA systems. In this article we extended the PF scheduling scheme to OFDM-based BWSs (OPF). In addition, we propose three variations: adaptive OPF (AOPF), multimedia AOPF (MAOPF), and normalized MAOPF (NMAOPF) in order to meet the QoS requirements for multirate services in multimedia systems. The adaptive modulation and coding schemes in time varying and frequency selective fading are considered. The system performances of the algorithms are compared in terms of efficiency (throughput and mean packet delay) and fairness (user satisfaction rate and average user rate). Joint physical and media access control layer simulation results show that AOPF and MAOPF can improve throughput at the cost of fairness, and NMAOPF can provide the highest throughput without losing fairness.     

Resource scheduling in downlink LTE-advanced system with carrier aggregation

In this paper,we focus on the resource scheduling in the downlink of long term evolution advanced (LTE-A) assuming equal power allocation among subcarriers.Considering the backward compatibility,the LT...     

E-UTRA中一种多业务两步比率公平调度算法

符合3GPP多业务处理原则的子信道调度方案是影响E-UTRA系统性能的关键技术。为减少填充和提高多用户分集效应,提出了一种多业务两步比率公平调度算法。在不区分用户业务优先级的情况下,先采用实际缓存量替代传统比率公平算法中的传输速率来分配子信道;业务优先级高的未分配用户再按比率公平算法确认的优先权重从低到高来挤占业务优先级低的用户所分配的子信道,从而确保符合3GPP提出的服务完高优先级业务后再服务低优先级业务的多业务处理原则。仿真结果表明,该算法能在保证用户公平的基础上提高系统吞吐量。     

Wireless Packet Scheduling Algorithm for OFDMA System Based on Time‐Utility and Channel State

In this paper, we propose an urgency‐ and efficiencybased wireless packet scheduling (UEPS) algorithm that is able to schedule real‐time (RT) and non‐real‐time (NRT) traffics at the same time while supporting multiple users simultaneously at any given scheduling time instant. The UEPS algorithm is designed to support wireless downlink packet scheduling in an orthogonal frequency division multiple access (OFDMA) system, which is a strong candidate as a wireless access method for the next generation of wireless communications. The UEPS algorithm uses the time‐utility function as a scheduling urgency factor and the relative status of the current channel to the average channel status as an efficiency indicator of radio resource usage. The design goal of the UEPS algorithm is to maximize throughput of NRT traffics while satisfying quality‐of‐service (QoS) requirements of RT traffics. The simulation study shows that the UEPS algorithm is able to give better throughput performance than existing wireless packet scheduling algorithms such as proportional fair (PF) and modifiedlargest weighted delay first (M‐LWDF), while satisfying the QoS requirements of RT traffics such as average delay and packet loss rate under various traffic loads.