基带资源池网络架构模型研究

传统的无线接入网架构面临着诸多挑战:系统容量干扰受限、多标准和动态网络负载缺乏灵活性以及高额的建设和运维成本等。本文对GSM移动通信网络和C-RAN架构的网络覆盖特性进行分析。在多个小区达到相同覆盖效果的情况下,对新旧两种网络结构的设计需求进行比较分析。C-RAN架构是一种新型的网络架构,针对该网络架构的特性,对解决潮汐问题进行可行性分析。     

C-RAN在CDMA2000网络的应用探讨

文章首先介绍了C-RAN网络架构;然后针对CDMA2000网络现状进行分析;最后从C-RAN的应用结构、应用优势和应用挑战三方面探讨了CDMA2000无线接入网的C-RAN演进。     

港珠澳大桥线性场景覆盖方案及应用案例

针对港珠澳大桥特殊的地理环境、复杂的线性无线环境以及未来的网络通信要求,以贴近客户感知的网络角度出发,从规划设计、工程施工、网络容量、信号干扰四个方面进行探讨,兼顾系统后期技术升级和演进,提出一种有效的通信网络覆盖方案,即采用C-RAN(无线接入网绿色演进)架构,为港珠澳大桥无线信号覆盖工作提供参考。     

无线协作Mesh网

异构无线网络的融合是当前无线网络的发展趋势。针对融合过程中遇到的诸如传输模式选择、负载平衡、路由和切换之类的问题,文章提出了一种新的网络融合架构：无线协作Mesh网。该架构基于无线Mesh网的网络结构,并通过协作通信进一步优化其结构、提升其性能。该架构能充分发挥Mesh技术高频谱效率、动态自组织的优点和协作通信高分集增益、高能量效率的优点,可为无线网络融合提供一种有效的解决方案。     

LTE-A上行CoMP软信息合并接收算法

为了提高边缘用户的吞吐量和服务质量,LTE-A系统引入了协作多点传输(coordinated multi-point transmission,CoMP)技术.针对LTE-A上行CoMP联合处理技术,在原始数据合并和硬判决动态选择算法的基础上,提出了一种软信息合并接收算法.理论分析和系统级仿真证明,其结合了两种传统算法各自的优点,吞吐量增益介于两种传统算法之间,极大地降低了X2链路负载,且充分利用了各个eNode B的基带处理能力,提高了网络的健壮性和容错性.     

OTN设备承载LTE 4G回传业务的浅析

本文结合新的C-RAN（集中式/协作式/云计算无线接入网）网络架构,提出了基于OTN的LTE 4G回传业务承载解决方案,从而降低移动无线网络的建设成本和网络运营成本,为新一代C-RAN接入汇聚传送网提供一种可靠的解决方案。     

云无线接入网的系统架构和技术演进

云无线接入网(cloud radio access network,C-RAN)被认为是有望解决第五代移动通信(5G)技术服务需求问题的核心技术方案之一,已有研究表明C-RAN具有显著的技术优势,能有效提升网络的谱效率和能效率。总结了C-RAN的研究现状,给出了其系统架构和核心关键技术挑战,并讨论了C-RAN架构相比传统方案具有的优势和性能提升。     

联合传输技术中关于协作集划分的研究

多点协作技术(Coordinated multi-point ,CoMP)是无线蜂窝系统LTE-Advanced(LTE-A)中改善边缘用户性能的一项关键技术。而CoMP中协作集的划分又是影响系统性能的一个重要因素,因此本文针对CoMP的协作集划分问题进行了研究,提出了一种基于用户实时位置状况的半动态非重叠协作集的划分算法。仿真结果表明本文提出的方案与静态协作方案和非协作方案相比,很好地改善边缘用户通信质量。     

基于C-RAN的5G无线接入网架构

在分析传统蜂窝结构的无线接入网面临越来越多的挑战的基础上,介绍了当前移动通信系统的发展趋势和需求,分析了第五代移动通信系统(5G)的研究目标以及对未来网络的要求.针对该问题,提出了基于C-RAN的新型5G无线接入网架构,并进一步阐述了5G通信系统网络架构的潜在关键技术,包括UND、虚拟化,SDN、NFV、CDN和绿色通信,为5G网络架构研究提供参考.     

面向5G的C-RAN技术与C-RAN规划案例分析

【】为更好的做好现阶段的4G C-RAN规划和分阶段实施工作,本文试图分析未来5G技术对网络架构产生的影响,为现阶段C-RAN工作提供经验分享和案例参考。重点分析了未来5G无线网设备形态、基于NGFI+C/U分离的的RAN架构,并以某地区C-RAN区域划分、机房规划为实际案例,介绍了其向5G网络架构演进的预判和思考。     

基于C-RAN目标网实现网络降本增效的方法探索

C-RAN技术的出现,在某种程度上“颠覆”了传统的移动通信网络架构,那么如何利用这把利器,我们经过了一系列探索、思考、实践,提出了C-RAN目标网的概念。以C-RAN站点作为基础,重构无线网、传输网,网络结构大大简化,降本增效成效显著。     

Resilient BBU placement in 5G C-RAN over optical aggregation networks

Photonic Network Communications - The huge data demand envisioned for the 5G requires radical changes in the mobile network architecture and technology. Centralized radio access network (C-RAN) is...     

C-RAN系统中的软件基带信号处理技术

云无线接入网(C-RAN)是融合了集中化处理、协作无线电和实时云计算的无线接入网架构,不同于传统无线通信网络架构,其基带处理单元基于统一开放的软件无线电平台。本文从灵活性、实现复杂度、运算精确度、处理时延、吞吐量、资源利用率、能耗等方面对比C-RAN系统中的软件发送接收技术与传统基带信号处理技术,并以低密度奇偶校验码(LDPC)编码载波传输系统为典型案例,展示软件技术运算精确度高、性能优良,而传统技术处理时延低的特点。     

C-RAN协作通信系统中基于正交预编码的同步算法

在C-RAN( Centralized,Cooperative,Cloud RAN)无线网络架构中,协作多点传输受到符号定时偏差和载波频率偏差的影响。为了降低联合传输协作系统对异步信号的敏感性,将正交预编码的同步算法应用到联合传输协作系统中。首先,发射机发送经过重复编码和正交预编码矩阵处理后的数据信息;然后,接收机利用特定的接收矩阵,实现分离相互叠加的异步协作信号;最后,完成对协作信号载波频率偏差和符号定时偏差的估计和补偿。理论分析和仿真结果表明：该方法能够有效解决协作传输中信号异步问题,改善系统性能。     

Dynamic Virtual Resource Allocation in Virtualized multi-RAT Cellular Networks

The legacy wireless systems are designed to exploit static configuration and deployment, and cannot handle the discrepancies of the spatio-temporal traffic demand. Cloud RAN (C-RAN) is a novel flexible radio technology that utilizes the virtualization concepts and can efficiently address the static deployment of conventional wireless systems. The C-RAN also leverages high radio network flexibility by introducing the network function virtualization approach to wireless networks. This paper presents a novel C-RAN platform that virtualizes and operates with full GSM and LTE systems. The presented platform is solely based on open-source and off the shelf solutions, providing easy implementation, low cost and high scalability. The paper also introduces a novel dynamic resource allocation algorithm that facilitates the C-RAN’s optimal performance in dynamic scenarios. The proposed algorithm is analyzed and validated on the presented C-RAN platform. The results of the performance analysis clearly show the advantages of the proposed dynamic resource allocation algorithm. Moreover, they prove the applicability of the C-RAN platform for variety of different scenarios.     

QoS support for an all IP system beyond 3G

Mobile radio systems beyond the third generation will evolve into all-IP systems, integrating Internet and mobile system advantages. The BRAIN project is developing a system architecture which combines local coverage broadband radio access systems based on HIPERLAN/2 with several wider-coverage mobile radio systems, enabling full coverage of seamless IP-based services for users in hot spot areas and on the move. End-to-end QoS provision is one of the major challenges in the design of such a system and must be supported by the application, network, and wireless access layers. This article proposes a QoS system architecture, including the terminal architecture, the IP-based access network, and the main characteristics of the enhancements to the air interface based on HIPERLAN/2 focusing on its wireless QoS support     

A programmable optical network testbed in support of C-RAN: a reliability study

With both mobile network services and related data traffic volume on the rise, reliability of the radio access network is of the essence. A number of radio functional splits are defined by 3GPP to offer increased flexibility of implementation and feasibility of new mobile network services. For example, it is possible to implement certain radio functions in the Cloud, an architectural solution referred to as C-RAN. C-RAN solutions require highly reliable backhaul and fronthaul network designs. This paper describes PROnet, a programmable optical software-defined network testbed, which has been upgraded to offer backhaul and fronthaul transport capabilities in support of C-RAN functionalities with increased reliability. The testbed is upgraded with a specially designed 1 + 1 protection mechanism at the Ethernet layer in order to meet the stringent network round-trip requirements imposed by one of the C-RAN functional split options on the fronthaul.

     

Multi-service small-cell cloud wired/wireless access network based on tunable optical frequency comb

In this paper, we demonstrate a novel multi-service wired/wireless integrated access architecture of cloud radio access network (C-RAN) based on radio-over-fiber passive optical network (RoF-PON) system, which utilizes scalable multiple-frequency millimeter-wave (MF-MMW) generation based on tunable optical frequency comb (TOFC). In the baseband unit (BBU) pool, the generated optical comb lines are modulated into wired, RoF and WiFi/WiMAX signals, respectively. The multi-frequency RoF signals are generated by beating the optical comb line pairs in the small cell. The WiFi/WiMAX signals are demodulated after passing through the band pass filter (BPF) and band stop filter (BSF), respectively, whereas the wired signal can be received directly. The feasibility and scalability of the proposed multi-service wired/wireless integrated C-RAN are confirmed by the simulations.     

A new C-RAN architecture based on RF signal soft-switching

Coordinated multi-point (CoMP) is known to be one of the key technologies for long-term evolution (LTE)-advanced systems. CoMP technology can improve system capacity and the quality of wireless communication services for users in LTE networks. However, in practice, the actual performance of CoMP technology is limited by the switching capacity of the backhaul network among distributed base stations as well as its latencies. In this paper, we propose a new cloud radio access network architecture based on RF signal soft-switching to solve this problem. Furthermore, we introduce a narrow-band parallel processing technique on a common public radio interface in downlink and uplink to reduce the volume of data as well as the latencies in the transmission process among base band units and remote radio units. By combining theoretical analysis with computer simulations, we show that the technique is valid both for downlink and uplink, i.e., it does not degrade the performance of downlink and uplink propagation between BBU pool and user equipments. Moreover, the computational time of the narrow-band parallel processing technique is less than that of the standard technique.