基于IEEE 802.16a的宽带无线接入系统

IEEE802.16a是固定宽带无线接入系统最新国际标准,基于该标准的宽带无线接入系统在无线传输方面具有调制方式动态选择的特点,可支持多业务;介绍的宽带无线接入系统具备IEEE802.16a建议的物理层、MAC子层、业务汇聚子层、及加密子层等实体,同时描述了一个实际的宽带无线接入系统必须具备的业务接口处理及系统管理等实体,并给出了各实体间的关系。     

IEEE 802.16无线接入技术的发展现状

随着信息产业的飞速发展,通信技术和计算机技术的融合已经成为必然趋势,因特网的出现则更加加快了两种技术的融合.全球通信产业呈现出移动化、宽带化、IP化的趋势.IEEE 802.16e的出现正好迎合了这样的发展趋势,兼具了移动、宽带和IP化的特点,是一种很有发展潜力的无线接入技术.     

IEEE802．16宽带无线接入技术

本文主要介绍了IEEE 802.16无线宽带接入技术的发展背景和技术特点,并将其与IEEE 802.11以及IEEE 802.20等相关技术进行了比较。结果表明:IEEE 802.16与IEEE802.11相比,覆盖范围更大,传输速度更快;与IEEE 802.20相比,则具有成本低、易实现的优势。所以,IEEE 802.16已被认为是最具潜力的无线宽带城域网技术,成为众人关注的焦点。     

IEEE802.16标准中OFDM技术研究

描述了802.16—2004中OFDM和OFDMA的物理层特性．比较了两种固定宽带无线接入系统的空中接口的异同点,就物理层参数设计(如信道带宽和中心频率、调制编码方式)．帧结构子信道分配、距离修正和带宽请求过程进行了详细阐述。     

Broadband wireless access

This article reviews the technologies and potential markets, applications, and architectures for broadband wireless access. The emergence of wireless communications for cellular systems is presented, together with its projected future evolution to mobile wideband systems. The field of broadband access systems, services, and network architectures is also covered, and then systems for broadband wireless communications for indoor local area networks and outdoor public fixed access networks are discussed. Broadband wireless access systems are emerging as a new and growing area of telecommunications, since the ability to provide access without extensive installation of copper or fiber infrastructures make wireless technology well suited for broadband services. Finally, some of the key enabling technologies, such as adaptive antennas and video compression, and the future architectural directions of broadband wireless networks are presented     

基于802.16接入的端到端切换机制研究

对802.16无线接入网络的端到端切换机制进行了分析研究,结合802.16接入网络的特点,使用SIP协议实现端到端切换,提出了旨在减少切换时延和丢包的网络设计构架。     

The IEEE 802.16 Working Group on broadband wireless

This article describes the new initiative on broadband wireless access (BWA) that has formed Working Group 802.16 in the IEEE 802 LAN/MAN Standards Committee. The aim is to provide the reader with highlights of the IEEE 802 activities in order to enable better dissemination of these standards into marketable products as well as seek new ideas to be brought into the IEEE 802 arena. BWA systems, utilizing base stations to provide broadband data to business or homes, offer an alternative to wired “last-mile” access links using fiber, cable, or telephone lines. As illustrated, the base stations may be either terrestrial, in orbit, or mounted on airplanes or dirigibles in the stratosphere. The customer terminals can carry two-way communications for Internet access, digital video, telephony, and other services     

宽带无线接入网IEEE 802.16标准

IEEE 802.16标准是一种“最后一英里”的无线宽带接入解决方案IEEE 802.16标准对工作在10～66 GHz的LMDS系统的低层作了规范,包括加密子层IEEE 802.16标准将加快世界范围的无线宽带城域网的发展进程     

IEEE802.16e移动宽带无线接入技术

对802.16e进行了较为详细地介绍和分析,包括基本特点、主要应用、空中接口规范协议模型、物理层、MAC层等.     

Broadband wireless access with WiMax/802.16: current performance benchmarks and future potential

The IEEE 802.16 family of standards and its associated industry consortium, WiMax, promise to deliver high data rates over large areas to a large number of users in the near future. This exciting addition to current broadband options such as DSL, cable, and WiFi promises to rapidly provide broadband access to locations in the world's rural and developing areas where broadband is currently unavailable, as well as competing for urban market share. WiMax's competitiveness in the marketplace largely depends on the actual data rates and ranges that are achieved, but this has been difficult to judge due to the large number of possible options and competing marketing claims. This article first provides a tutorial overview of 802.16. Then, based on extensive recent studies, this article presents the realistic attainable throughput and performance of expected WiMax compatible systems based on the 802.16d standard approved in June 2004 (now named 802.16-2004). We also suggest future enhancements to the standard that could at least quadruple the achievable data rate, while also increasing the robustness and coverage, with only moderate complexity increases     

基于OFDM的IEEE802.16a物理层简介

简要介绍了IEEE802.16的基本概况,描述了IEEE802.16a标准采用的几种物理层方案。IEEE802.16a协议物理层支持的主流技术就是OFDM技术,重点介绍了OFDM的基本原理,采用OFDM调制技术的WirelessMAN OFDM系统,以及其物理层的一些参数及性能。最后介绍了2种双工方式的帧结构及其工作原理。     

Remote locations coverage analysis with wireless mesh networks based on IEEE 802.16 Standard

This article analyzes the wireless coverage problem of remote regions with low user density and propagation problems due to irregular terrain and high tree density. The use of a wireless mesh network is proposed as a solution where user data is transmitted directly to a base station when it is possible or relayed through other nodes in a multi-hop manner when there is not a direct link. The mesh topology uses short links with higher capacity instead of long links with low capacity. We analyze radio propagation and MAC protocols, including random sources, queues, and packet delays. The article is based on the coverage of a realistic rural region near Medellin, a mid size city in Colombia, and it shows that a wireless mesh network is an alternative to a typical cell based solution. It includes propagation analysis and MAC protocol behavior, so it is not limited to a radio coverage problem but also traffic, scheduling, and routing analysis     

基于IEEE 802.16a的OFDM基带调制系统的FPGA设计

本文研究了基于IEEE802.16a的OFDM基带调制系统的实时实现,提出了一种切实可行的IEEE802.16a的OFDM调制方式的FPGA实现方法与结构,并介绍了IFFT运算、QPSK映射和插入循环前缀的具体电路。最后给出了硬件性能分析。     

IEEE 802.16/WiMAX-based broadband wireless access and its application for telemedicine/e-health services

In this article we investigate the application of IEEE 802.16-based broadband wireless access (BWA) technology to telemedicine services and the related protocol engineering issues. An overview of the different evolutions of the IEEE 802.16 standard is presented and some open research issues are identified. A survey on radio resource management, traffic scheduling, and admission control mechanisms proposed for IEEE 802.16/WiMAX systems is also provided. A qualitative comparison between third-generation wireless systems and the IEEE 802.16/WiMAX technology is given. A survey on telemedicine services using traditional wireless systems is presented. The advantages of using IEEE 802.16/WiMAX technology over traditional wireless systems, as well as the related design issues and approaches are discussed. To this end, we present a bandwidth allocation and admission control algorithm for IEEE 802.16-based BWA designed specifically for wireless telemedicine/e-health services. This algorithm aims at maximizing the utilization of the radio resources while considering the quality of service requirements for telemedicine traffic. Some performance evaluation results for this scheme are obtained by simulations     

基于IEEE 802.16a协议的OFDM系统的FPGA实现

主要介绍了OFDM的调制解调的FPGA实现,首先介绍OFDM的基本原理,然后给出了采用FPGA实现基于IFFT/FFT的OFDM调制解调的具体结构,以及插入循环前缀和去循环前缀的具体结构.     

基于IEEE 802．16d OFDM系统的FPGA设计

研究基于IEEE 802．16d OFDM系统的FPGA实现。首先探讨了基于802．16d的OFDM系统FPGA设计的构架。然后采用VHDL硬件描述语言实现了发送端和接收端各个模块。最后选用了Altera公司CycloneⅡ系列的EP2C35F484C6芯片,在QuartusⅡ软件环境下对VHDL代码进行了综合。     

Pilot Based Channel Estimation in IEEE 802 16a OFDM System

1　Introdution　IEEE 802 16[1] is a specification for fixed broadbandwireless Metropolitan Access Networks (MAN). The stan dard is expected to bring low cost and more bandwidth prod ucts for broadband wireless access in the next years. Thisstandard specifies the physical (PHY) and Medium AccessControl layer (MAC) of the air interface of interoperablepoint to multipoint and optional Mesh topology broadbandwireless access system. The specification enables access todata, …     

MAC Layer Concepts to Support Space Division Multiple Access in OFDM based IEEE 802.16

Advanced antenna technologies and algorithms have been developed during the last years. But until today, advanced antenna algorithms in the physical layer and the modes of operation in medium access layers have not been integrated in modern wireless systems. As one of the first standards the metropolitan area network IEEE 802.16 provides means to support smart antenna techniques.After a detailed introduction of the medium access control layer this article outlines the support of space division multiple access (SDMA) techniques by the wireless metropolitan area network IEEE 802.16. New concepts are introduced that allow and further optimize the use of SDMA techniques brought by intelligent antennas. First, the possibility to enable SDMA in the IEEE 802.16a-2003 protocol is investigated, and second the support of SDMA in the revised 802.16-2004 standard is elaborated in detail. To overcome current limitations of 802.16a-2003, an enhanced control structure is introduced in 802.16-2004 that masters a concurrent transmission and reception of data to/from several different subscriber stations. The approach facilitates a fully flexible structure which significantly improves system capacity. Christian P. Hoymann received his Diploma degree in electrical engineering from RWTH Aachen University in 2002. Before he served a student internship at SIEMENS Corporate Research, Princeton, USA. Since 2002 he is employed as a Research Assistant at the Chair of Communication Networks (ComNets) of RWTH Aachen University where he is working towards his Ph.D. degree.He worked in the fields of traffic engineering and dimensioning of GSM/GPRS networks together with his project partners at D2 Vodafone. He was actively involved in the IST-STRIKE project where smart antenna systems had been integrated in Metropolitan Area Networks. His current research interests include the optimization of MANs especially in consideration of smart antenna technologies such as SDMA and relaying technologies such as Mesh.Mr. Hoymann has published several conference and journal papers and was actively involved in the standardization of SDMA technologies for IEEE 802.16.     

IEEE 802.16宽带无线接入系统中基于QoS的调度算法

本文介绍并评估了几种支持IEEE 802.16标准QoS要求的包调度算法,并将它们的重要性能进行了比较.     

无线宽带IEEE802.16d物理层仿真

针对WiMAX物理层研究的重要性以及根据WiMAX标准所规定的有限测试向量来测试系统带来的不便,利用动态系统仿真工具Simulink按照IEEE802.16d物理层标准构建了一完整的端对端的系统模型,将指标文档变成了一个动态的可执行模型,大大方便了对系统的测试和分析。同时为IEEE802.16d/e两种标准下的信道、均衡、同步算法的研究与应用提供了一个有效的研究平台,对WiMAX标准的研究与开发很有意义。