Am7910／11调制解调器芯片特性与应用

以实际应用为目的，较详细地介绍ＦＳＫ调制解调器专用芯片Ａｍ７９１０／７９１１的特点、电路结构、外部连接方法及技术性能，简述了工作原理并给出了典型应用电路。     

Am7910／11调制解调器芯片特性与应用

以实际应用为目的，较详细地介绍了ＦＳＫ调制解调器专用芯片Ａｍ７９１０／７９１１的特点、电路结构、外部连接方法及技术性能，简述了工作原理并给出了典型应用电路。     

短波调制解调器性能研究

分析了短波调制解调器的基本工作原理,并对两种标准的串行和并行短波调制解调器进行了性能测试和比较,对两种体制的短波调制解调器在数字话音和数据传输中的应用进行了分析。     

蓝牙射频技术的分析与应用

从蓝牙技术的基本原理出发。较详细地分析了蓝牙的关犍技术之一——射频技术。同时例举了利用其射频原理实现蓝牙芯片拓展应用的范例。     

无线数据传输机在水源地中的应用

本文介绍了无线数据传输机的原理，讨论了局域网的建立，论述了无线通讯机ＦＳＫ调制解调器等在实际工程中的应用。     

无线调制解调器应用于短波通信

介绍了无线调制解调器73M223的原理、特点和性能，结合短波信道的数据传输进行了73M223的具体应用电路设计和实现，提供了利用现有短波电台实现数据传输的解决方案。     

无线信道1200／2400调制解调器的设计

本文讨论了利用无线话音信道（２５ｋＨｚ间隔）传输数据速率为１２００／２４００波特的调制解调器（ＭＯＤＥＭ）的设计。ＭＯＤＥＭ采用了较先进的ＭＳＫ调制技术，可完成同步／异步方式的通信，通过编制不同的软件，可灵活地支持各种通信协议。     

DM196-MAP集群调制解调器及其在模拟集群网络中进行数据传输的应用

该文介绍DM196-MAP无线集群调制解调器的原理和特点,并给出它在350M公安集群网络中进行综合信息交换的一个应用实例。该实例综合使用无线调制解调技术、GIS信息技术、多路接入技术、Client/Server结构的数据库应用技术和嵌入式系统终端技术,并结合Map27协议控制技术,在公安模拟集群网络上实现高达9600bps的数传达率,使在模拟集群系统上开展多种数据通信业务成为可能,进而提升了模拟集群系统的业务功能。     

电缆调制解调器技术及其Internet接入方案

在Internet接入研究中，电缆调制解调器（Cable Modem）是一种先进的高速解决方案。首先简要介绍了电缆调制解调器出现的背景，然后阐述了电缆调制解调器的技术原理及其优缺点。最后详细介绍了电缆调制解调器的国际标准和利用电缆调制解调器接入Internet的几种方式，并指出了其应用前景。     

PDA调制解调器的设计与实现

介绍了一种新型的PDA调制解调器的设计 ,详细地分析了该调制解调器电路的工作原理并介绍了该调制解调器驱动程序的设计。     

Dynamic spectrum access in IEEE 802.22- based cognitive wireless networks: a game theoretic model for competitive spectrum bidding and pricing [accepted from open call]

The emerging IEEE 802.22-based wireless regional area network technology will use the same radio spectrum currently allocated for TV service. This standard will use the concept of cognitive radio based on dynamic spectrum access to provide wireless access services in a large coverage area. A brief overview of the current state of the IEEE 802.22 standard is provided with a particular emphasis on the spectrum management (i.e., spectrum sensing and dynamic spectrum access) in this standard. Key research issues related to spectrum trading among TV broadcasters, WRAN service providers, and IEEE 802.22-based cognitive radio users are identified. To this end, a hierarchical spectrum trading model is presented to analyze the interaction among WRAN service providers, TV broadcasters, and WRAN users. In this model a double auction is established among multiple TV broadcasters and WRAN service providers who sell and buy the radio spectrum (i.e., TV bands), respectively. Again, multiple WRAN service providers compete with each other by adjusting the service price charged to WRAN users. We propose a joint spectrum bidding and service pricing model for WRAN service providers to maximize their profits. A non-cooperative game is formulated to obtain the solution in terms of the number of TV bands and the service price of a service provider. Numerical results are presented on the performance of this joint spectrum bidding and pricing model.     

Interference Analysis of TV-Band Whitespace

Cognitive radio (CR) has been suggested as a method for promoting more efficient spectrum usage through the principles of spectrum sensing and dynamic spectrum management. The IEEE 802.22 working group in particular is developing a wireless regional-area network (WRAN) standard that will employ unlicensed CR devices operating on a noninterfering basis in the commercial broadcast television (TV) bands. Before such TV-band CR networks can be deployed, the maximum levels of first adjacent and taboo channel interference that a digital television (DTV) receiver can tolerate must be determined. In this context, we will first provide an overview of the IEEE 802.22 WRAN system. Afterwards, we will report on an experimental study that was undertaken to characterize IEEE 802.22 WRAN interference limits into Advanced Television Systems Committee (ATSC) based DTV receivers. Lastly, we will discuss the implications of these WRAN interference limits in terms of the maximum allowable radiated power and out-of-band emission limits that are imposed on WRAN end-user devices.     

宽带无线接入系统中抑制多径效应的关键技术

主要介绍宽带无线接入系统中的多径效应，以及采用VOFDM技术抑制我径效应的机理，分析基于VOFDM和DOCSIS MAC的无线调制解调器工作原理和提高通信质量的关键技术。     

软件定义无线接入网络的组件化研究

针对5G通信技术高传输速率、多业务场景的挑战,该文提出一种组件化的软件定义无线接入网络新架构。该架构在5G接入网集中单元(CU),分布单元(DU),有源天线单元(AAU)架构的基础上,进一步朝组件化方向演进,形成一种由集中控制单元(CCU), CU, DU,射频单元(RU),AAU等组件化通信单元组成的新架构。这种新架构既有利于切片化、虚拟化实现无线接入网,又有利于应用分布式计算技术和硬件加速技术突破通用处理器的计算能力瓶颈,还能降低DU与AAU之间的前传压力。该文还研制了基于此架构的组件化软基站试验原型并进行了测试,结果表明该组件化方案在提供高度灵活性的同时,还能够提升通用处理器软基站的吞吐能力,并有效降低远端站址传输流量。     

有线无线卫星融合技术的研究与探讨

伴随着信息技术的发展,广电网络必须借助5G技术发展的有利条件,实现广播电视有线无线卫星融合技术的快速发展按照NGB网络建设的基本架构,采用成熟的LTE技术,在业务功能和应用上进行研究总结,因地制宜实现用户的接入需求。     

以太网技术在基于同轴电缆的多住户单元中的应用

利用调制解调技术将以太网信号合成在同轴电缆中和CATV信号一同传输,实现包括视频点播（VOD）、网络电视（IPTV）、宽带上网及数字音频（VOIP）等能够承载多种业务的双向宽带网络功能。     

基于GSM-Hi技术的农村无线宽带建设方案及部署策略

当前宽带建设的重点集中在城市地区,而农村地区目前2G和3G仍作为农村无线数据业务的主要承载网络,宽带设施发展水平提升并不显著,不能适应农村互联网快速发展的需要.因此,如何实现农村宽带接入建设,解决农村区域上网难的问题显得尤为重要,GSM-Hi技术应运而生.     

Utility Function Selection for Streaming Videos with a Cognitive Engine Testbed

Cognitive Radio (CR) is a new wireless communication and networking paradigm that is enabled by the Software Defined Radio (SDR) technology and the recent change in spectrum regulation policy. As the first commercial application of CR technology, IEEE 802.22 wireless regional area networks (WRAN) aim to offer broadband wireless access by efficiently utilizing the unoccupied TV channels. In this paper, we investigate the problem of utility function selection and its impact on streaming video quality through an IEEE 802.22 WRAN base station (BS) cognitive engine (CE) testbed developed at Wireless@Virginia Tech. We find that significant improvement on received video quality can be achieved when CE adopts a dynamic, content-aware, video-specific utility function rather than a static, predefined, general purpose utility function. This work indicates the importance of video distortion modeling and cross-layer design, and the need for employing dynamic content-aware utility functions at the CE for cognitive streaming video communication networks.     

移动WiMAX与Wi-Fi融合关键问题分析

无线接入互联网和无线多媒体数据业务的市场需求推动了无线通信技术的快速发展,通信技术宽带化、IP化、移动化成为未来的发展趋势.其中具有代表性的技术就是:Wi-Fi和移动WiMAX技术.本文从市场、技术、运营的角度来分析移动WiMAX和Wi-Fi的定位,探讨二者融合的可行性并给出建议.