RF-MEMS for Wireless Communications [Topics in Design and Implementation]

This article presents an introduction and overview of MEMS technology with a focus on RF applications of MEMS in the design of cellular handsets. A novel, integrated, high-Q tunable digital capacitor is discussed to demonstrate how RF-MEMS technology can be utilized to make high frequency components whose RF characteristics can be adjusted during operation, allowing for the first time reconfiguration of radio hardware under software control. It is concluded that as the consumer wireless market continues to grow and evolve, product designers will remain under ever increasing pressure to develop smaller, lighter, thinner products that are more functional, energy-efficient, and intuitive, and to do so faster and at lower cost. Although issues and challenges persist, opportunities abound, and RF-MEMS technology holds the promise of being a key enabler of future generations of more highly converged, cognitive, and flexible consumer wireless products.     

软件无线电收发信机的设计实现

当今通信技术由模拟式向数字式、软件化方向快速发展,在此介绍了一种基于软件无线电技术的无线收发信机系统设计方案。其中采用了Intersil公司全数字上变频器HSP50415、全数字下变频器HSP50214B、数字科斯塔司环HSP50210与单片机AT89S8252、数字信号处理芯片TMS320VC5409及可编程逻辑器件EP1K30等构成系统的核心处理单元,通过软件实现对信号的无线收发。     

软件无线电系统中NCO的设计与实现

介绍了软件无线电系统中基于FPGA的数控振荡器(NCO)的实现方法，详细讨论了查找表和CORDIC算法的原理。通过软件仿真和测试，所设计的数控振荡器可以根据系统输出精度和硬件资源的不同，通过选择不同算法和参数来满足系统设计的要求。     

短波测向软件的设计与实现

随着当今世界无线电技术和业务的快速发展以及社会需求的日益增长,空中电磁环境日趋复杂,各种无线电干扰时有发生,无线电监测的任务日趋繁重。介绍了一套短波监测系统中测向功能的设计与实现,其中介绍了无线测向的基本原理,详细分析了软件和测向设备EBD061之间的CORBA通信模式以及测向程序的基本流程和具体实现。     

Time-limited leases in radio systems [Topics in Radio Communications]

A time-limited lease is a set of rights that expires after a specified duration. We analyze ways to use leases to facilitate innovation in radio devices and wireless communication. In our vision, manufacturers include in their devices a simple, secure subsystem that contains a clock and disables specific transmit capabilities if no extension message is received by the end of the lease period. When devices provide this support, regulators may use certification leases rather than permanent grants to accelerate deployment of innovative radios. Spectrum rights holders may use leases to reduce risk in secondary spectrum market transactions. Firms collaborating in innovative wireless service business models can better retain control of their respective rights. We examine both the technical and policy issues associated with leases.     

Design of a DVB-T/H COFDM Receiver for Portable Video Applications [Topics in Circuits for Communications]

Mobile video services have generated a lot of interest recently. To reach a cost-effective solution, design trade-offs among system performance, hardware complexity, and power consumption must be considered in the early design phase of such applications. In this article, we present a system overview, simulation platform, and hardware design of a DVB-T/H baseband receiver. Starting with a design platform, several algorithms on both inner and outer receivers are developed to meet target system performance under different channels. Then, system architecture and related key modules are explored, taking into account both silicon area and power consumption. Finally, several design issues related to the integration of the proposed DVB-T/H inner and outer receivers are addressed.     

软件无线电数字变频系统设计与实现

根据软件无线电数字变频的原理,设计和实现了基于软件无线电的数字变频系统.通过System Generator系统设计工具,重点进行了NCO,CIC,HB和FIR滤波器等系统组成部分的建模设计,并没有直接调用System Generator设计工具自带的完整功能模块,其中CIC采用Hogenauer滤波器设计,FIR滤波...     

软件无线电中数字变频器的设计与实现

数字变频技术是软件无线电的关键技术之一。本文给出了一个基于Intersil公司的数字上、下变频器件的数字变频器设计方案，并通过硬件实验证明本设计方案的可行性。     

Shared spectrum access for the DoD [Topics in Radio Communications]

Increasing demands are being placed on spectrum access, both domestic and abroad, as a result of current demands for global mobility, electromagnetic spectrum requirements of both outdated and future defense systems, and loss of military access to certain frequency bands due to spectrum legislation. Consequently, the DoD should identify shared spectrum access opportunities and explore dynamic spectrum access technologies to help meet the growing spectrum requirements of the military. This article discusses a few cases of current and future shared spectrum access environments to highlight the circumstances for spectrum sharing and utilization of military and commercial frequency bands.     

On Spam over Internet Telephony (SPIT) Prevention [Topics in Design and Implementation]

Spam over IP telephony (SPIT) is expected to become a serious problem in the near future. One of the main requirements for a SPIT prevention system is to avoid the involvement of the callee in the SPIT detection process, because this implies disturbing the callee each time an unclassified potential SPIT call arrives. Further requirements include adaptability to different deployment scenarios and flexibility to quickly react to new kinds of SPIT that bypass existing prevention systems. This article analyzes the requirements for SPIT prevention, provides a systematic classification of currently known SPIT prevention methods, and introduces a reference model for SPIT prevention systems. As an instance of the reference model, we designed and implemented an advanced SPIT prevention system, composed of methods that avoid unnecessary callee interaction and adaptive in order to be customized for different scenarios.     

基于FPGA的软件无线电调制器设计与实现

针对数字基带信号的特点和通信系统中对数字信号传输的要求,研究一种基于FPGA的DSP技术和DDS技术的软件无线电调制器的设计方法。在FPGA平台上设计具有ASK,FSK,PSK和QAM调制功能的软件无线电调制器。该系统具有可重复编程和动态重构的优点,使系统易于修改和功能升级,灵活性强。     

基于OMAP软件无线电平台设计与实现

文章根据软件无线电的基本原理,使用OMAP3530处理器和FPGA,设计了一个新型的软件无线电平台,以满足高性能、低功耗和便携性的需求。     

XG dynamic spectrum access field test results [Topics in Radio Communications]

The XG Radio system uses dynamic spectrum access technology to determine locally unused spectrum, and then operates on these channels without causing interference to existing non-cooperative users. In August 2006 the XG Radio system was field tested at Fort A.P. Hill, Virginia, in the laboratory, and at field locations in Northern Virginia. There were three major test criteria: to cause no harm (avoid interference), to work (form and maintain connected networks), and to add value (efficiently use spectrum). This article defines the test metrics for fulfillment of these criteria, and describes the test results.     

Timing Synchronization in MF-TDMA Systems for Geostationary Satellites[Topics in Radio Communications]

The most expensive costs in satellite communication are incurred by the space segment. Therefore, effort should be focused on the efficient use of this resource. One aspect is the optimization of the physical layer, to approach the Shannon limit of channel capacity. In IP-based networks, communication between arbitrary terminals can be established, which must hold for IP-based satellite networks as well. A commonly used topology is the star network, where data are routed via the master station, which in case of satellite communications introduces a double hop for terminal-to-terminal connections [1]. A double hop requires twice the bandwidth and twice the response time, which is very unattractive for interactive services. This drawback is avoided with a fully meshed topology, where terminals can communicate directly. Of course, an appropriately designed access system is required in this context. The well-known multi-frequency, time-division multiple access (MF-TDMA) scheme slices the channel capacity along both time and frequency axes. Each fragment (slot) can be used by any station for direct communication [2, 3]. This article describes the method on an abstraction layer, starting with the high-level timing that copes with frame numbers; the low-level timing that maps the frame numbers to time instants of the local time scale; and ends with the time stamp handled in the hardware, where calculation delays and filter flushing affect the received time stamp. Compared to commercial systems, the method described in this article uses differential time stamps, which reduces the effort of the synchronization procedure.     

一种软件无线电台的设计

软件无线电(Software Radio)是以开放体系结构为基础,在硬件平台上应用软件工程技 术来实现具有最大灵活性和适应性的各种无线通信方式和功能的系统。介绍了一种软件无线电跳频电 台的设计,重点概述了总体方案。以接收机为对象分析了中频数字化、宽带射频电路、频率合成器,并适 当地给出了设计和计算。     

AcroTetra数字集群系统测试软件设计与实现

AcroTetra是一种符合TETRA标准的无线集群通信系统,系统的性能指标需要在大量无线频点及自动化的测试终端下进行长时间大密度测试。为了简化测试系统、减少电磁辐射、避免与产品无关的硬件开发,设计和实现了AcroTetra数字集群系统测试软件。测试软件模拟了真实信道机的协议栈、控制、配置及数据收发子系统,使背侧基站正常工作并且感知不到底层设备的变化,并对AcroTetra进行性能测试,通过对测试结果的分析,证明了测试软件的可用性。     

基于软件无线电的地下通信接收机设计与实现

为解决地下通信实现困难、接收端信号波动范围大的问题,研究了软件无线电接收机的原理和关键技术,设计了数字化地下通信语音调频接收机。根据信号流向,设计了80 dB大动态自动增益控制放大器,给出了数字正交鉴频结构,完成了语音终端设计,最后详细地阐述了接收机的软件设计和硬件实现。整个接收机具有较强的抗噪声性能。     

基于SCA的新型软件无线电系统设计与实现

由于无线通信技术的飞速发展,以及硬件组成性能的限制,当前主流的一些软件无线电(Software Defined Radio,SDR)外设已不能满足无线电研究人员的需求。基于一种面向5G通信自主开发的软件通用平台(Software Universal Platform,SOUP)和无线电软件开发平台GNU Radio,设计搭建了一种符合软件通信架构(Software Communication Architecture,SCA)的软件无线电系统。使用硬件驱动程序PDMA使主机识别SOUP、屏蔽SOUP底层硬件的实现细节,并使得操作系统能够像操作文件一样对SOUP进行操作,再使用GNU Radio的模块开发工具开发出信号源模块和信宿模块,这2个模块的功能就是用来采集和传送I/Q采样信号。通过实现一种传统的模拟通信系统,以验证SOUP_GNU Radio系统的有效性。     

软件无线电及其实现技术

软件无线电是一种新兴技术，通过软件使多种业务、多种标准、多个频段与灵活的无线电系统的组合成为可重新配置和可重新编程的。介绍了软件无线电的概念及系统结构，并进一步讨论了现阶段软件无线电所面临的技术问题以及相应的实现方案。     

基于软件无线电的中频数字化直扩系统的设计与实现

本文根据直接序列扩频原理,给出了一种基于软件无线电思想的中频数字化直扩系统的设计方案,并采用可编程数字器件实现。实验结果表明该方法达到了设计要求,并具有良好的通用性和灵活性。