安捷伦科技、ASTRI、PicoChip演示TD—LTE毫微微蜂窝基站的设计与测试

安捷伦科技公司、香港应用科技研究院（ASTRI）和picoChip公司日前宣布，将在2009年全球移动通信大会上共同进行TD—LTE演示。本次大会由TD—SCDMA产业联盟（TDIA）主办。这次演示使用安捷伦的测试设备，对ASTRI和picoChip公司共同设计的TD—LTE毫微微蜂窝基站进行测试。这也是TD—LTE毫微微蜂窝基站首次进行MIMO测试演示。     

安捷伦展示毫微微蜂窝基站测试能力

安捷伦科技公司日前在美国毫微微蜂窝基站展会（Femtocells USA）上展示了全面的毫微微蜂窝基站设计和测试产品,其中包括用于测试参考设计的首款3GPPLTE毫微微蜂窝基站测试系统。     

WiMAX CPE收发器之基站应用

与分立设计相比,单芯片WiMAX收发器能够显著节省成本和空间,但一直以来,严格的发射性能要求使其无法用于基站设计。最近,一些新型器件极大地改善了发射信噪比（SNR）性能,因而适合从毫微微蜂窝到微蜂窝的各类应用。     

集成电路

用于毫微微蜂窝基站的3G收发器用于3G Femtocell基站的ADF4602-1收发器支持面向家庭与办公无线基础设施设备的UMTS(通用移动通信系统)无线接口标准,内置频率合成器、滤波器以及电源管理电路。     

Picochip和香港应科院推出首款商用级LTE小蜂窝基站参考设计

英国PicoChip公司和香港应用科技研究院（ASTRI,以下简称应科院）近日宣布：双方已经顺利完成编号为PC8609的业界首款商用级LTE—FDD家庭基站（也被称为毫微微蜂窝基站）物理层软件的设计和验证。     

Ixia推出新型LTE小型蜂窝验证解决方案

全球领先的融合IP和无线网络测试解决方案提供商Ixia宣称,推出了用于验证LTE小型蜂窝系统的新型测试解决方案。Ixia的IxCatapult测试解决方案能够确保LTE毫微微蜂窝、微微蜂窝和微蜂窝的高性能、复原能力和品质。小型蜂窝为低功率的无线接入点,以授权频谱工作,能够将标准的移动设备连接到移动运营商的网络中。毫微微蜂窝与微微蜂窝可为客户和运营     

IXIA推出新型LTE小型蜂窝验证解决方案

近日,全球领先的融合IP和无线网络测试解决方案提供商IXIA宣称,推出用于验证LTE小型蜂窝系统的新型测试解决方案。IXIA的IxCatapult测试解决方案能够确保LTE毫微微蜂窝、微微蜂窝和微蜂窝的高性能、复原能力和品质。小型蜂窝为低功率的无线接入点,以授权频谱工作,能够将标准的移动设备连接到移动运营商的网络中。毫微微蜂窝和微微蜂窝可为客户和运营商带来诸多潜在益处,包括提高性能、加大覆盖范围以及从拥挤的宏蜂窝中卸载流量。     

家用基站迎来快速发展期

正如计算机的发展是从大型机、小型机到笔记本一样,基站也经历着从大到小的变迁：宏蜂窝基站、微蜂窝基站（microcell）、毫微微蜂窝基站（femtocell,俗称家用基站）。据统计,2010年家用基站的出货量是140万,同全球220万传统的宏基站相比,ABI预测,2012年以后,LTE小基站的部署数量将超过宏基站的数量,这个数字在2015年有望增至7020万,年复合增长率为154%!小基站真正迎来快速发展期。     

3G毫微微蜂窝模拟前端设计

毫微微基站通常称为毫微微蜂窝,可在家庭内实现移动电话接收功能,提供按月收费的无限量语音和数据服务.     

新型收发器推动微微蜂窝基站的发展

这些高集成度收发器支持工作频率为2.3GHz～2.7GHz和3.3GHz～3.8GHz的3G和4G微蜂窝和微微蜂窝系统,包括WiMAX和LTE系统。     

链路复用的跳频收发机射频前端设计

针对便携式跳频电台,设计了一种收发链路复用的收发信机射频前端。该收发信机射频前端可以提高抗干扰能力,达到降低功耗、减小设备体积的目的。详细介绍了收发信机射频前端的设计链路和硬件电路实现,设计中收发链路均采用二次变频结构,输出和输入频率在110～512 MHz之间连续可变。最后,对射频前端进行性能测试,测试结果表明所设计的射频前端实现了低相噪、低杂散、带内波动小和高速跳频等指标。     

Low‐Power Direct Conversion Transceiver for 915 MHz Band IEEE 802.15.4b Standard Based on 0.18 μm CMOS Technology

This paper presents the experimental results of a low‐power low‐cost RF transceiver for the 915 MHz band IEEE 802.15.4b standard. Low power and low cost are achieved by optimizing the transceiver architecture and circuit design techniques. The proposed transceiver shares the analog baseband section for both receive and transmit modes to reduce the silicon area. The RF transceiver consumes 11.2 mA in receive mode and 22.5 mA in transmit mode under a supply voltage of 1.8 V, in which 5 mA of quadrature voltage controlled oscillator is included. The proposed transceiver is implemented in a 0.18 μm CMOS process and occupies 10 mm² of silicon area.     

基于嵌入式的无线传感测试网络节点设计

无线传感网络不需要建设网络,可以大量快速布置,具有成本低的特点。在一些特殊的场合下,可以替代传统的有线测试网络。无线传感网络一般用于数据量较少场合,无法胜任需要较高的传输速率的场合。文中分析了影响无线传感网络使用的主要因素,通过选取混合网的网络拓扑结构,采用嵌人式微控制器LPC2129与单片收发射频芯片nRF241．01构建无线传感网络测试节点,提高了节点处理能力,同时功耗较低能够保证节点工作较长的时间,满足在一定时间内大量数据的传输要求。经过现场实测,节点设计满足设计要求。     

Small‐cell planning in LTE HetNet to improve energy efficiency

Cell planning is one essential operation in wireless networks, and it significantly affects system performance and cost. Many research efforts consider the cell planning problem with identical base stations (BSs) or to construct a new network on the region without any infrastructure. However, long‐term evolution (LTE) adopts heterogeneous network, which allows operators to tactically deploy small cells to enhance signal coverage and improve performance. It thus motivates us to propose a small‐cell planning problem by adaptively adding low‐powered BSs with the limitation of budget to an existing network to increase its energy efficiency, which is defined by the ratio of network throughput to the amount of energy consumption of BSs. We consider 2 types of LTE small cells, namely, microcells and picocells, and develop different clustering strategies to deploy these cells. Based on the available resource and traffic demand in each cell, we then adjust the transmitted power of the deployed BS with energy concern. Experimental results demonstrate that our small‐cell planning solution can achieve high‐energy efficiency of LTE networks, which means that BSs can better use their transmitted energy to satisfy the traffic demands of user devices. This paper contributes in proposing a practical problem for cell planning with heterogeneous network consideration and developing an efficient solution to provide green communications.     

基于软件无线电的短波SSB收发机

针对传统的单边带电台采用模拟实现技术存在的缺点,采用软件无线电设计思想,以数字信号处理技术为核心,设计了一种短波单边带数字化无线收发机。该单边带收发机采用宽带低通射频采样结构,利用数字上下变频技术实现从基带到射频之间的转换,以及正交调制解调方式。提出了基于现场可编程门阵列（FPGA）硬件平台的收发机设计思路与实现方法,仿真与实验结果表明,所设计的单边带收发机各功能部件均符合设计要求,总体性能也达到预期的效果。     

TD-LTE与FDDLTE基站射频测试方法差异性分析

对TD-LTE与FDDLTE的基本技术差异进行了分析,对LTE基站的RRU结构和相关射频测试项目作了介绍,并分析了二者在基站射频测试方法上的差异性。     

基于IEEE802．15．4／ZigBee的语音通信系统

提出一种基于IEEE802.15.4的无线传输方案,该方案基于Chipcon公司开发的一款符合ZigBee标准的低功耗射频芯片CC2420,设计了以MSP430为处理器、CC2420芯片为无线通信芯片的无线语音通信系统。使用的外围器件少,实现了短距离无线语音传输和方波输出的双向数据传输,并通过正弦波实验进行代码调试,具...     

A low voltage CMOS RF front-end for IEEE 802.11b WLAN transceiver

A low voltage CMOS RF front-end for IEEE 802.11b WLAN transceiver is presented. The problems to implement the low voltage design and the on-chip input/output impedance matching are considered, and some improved circuits are presented to overcome the problems. Especially, a single-end input, differential output double balanced mixer with an on-chip bias loop is analyzed in detail to show its advantages over other mixers. The transceiver RF front-end has been implemented in 0.18 um CMOS process, the measured results show that the Rx front-end achieves 5.23 dB noise figure, 12.7 dB power gain (50 ohm load), −18 dBm input 1 dB compression point (ICP) and −7 dBm IIP3, and the Tx front-end could output +2.1 dBm power into 50 ohm load with 23.8 dB power gain. The transceiver RF front-end draws 13.6 mA current from a supply voltage of 1.8 V in receive mode and 27.6 mA current in transmit mode. The transceiver RF front-end could satisfy the performance requirements of IEEE802.11b WLAN standard. Supported by the National Natural Science Foundation of China, No. 90407006 and No. 60475018.     

一种3.5 GHz频段双通道射频前端设计

随着5G商用网络的快速建设,国内5G网络测试设备存在大量空缺。为此,设计了一种适用于5G终端模拟器的3.5 GHz频段双通道射频前端。该射频前端结合了ADRV9009芯片,可同时支持双通道收发,具有器件数少、设计复杂度低的特点。实测结果表明,该射频前端性能稳定,接收灵敏度为-85 d Bm,噪声系数小于2.6 dB,256QAM调制下发射信号的误差矢量幅度为1.43%,达到了5G终端模拟器的设计要求。     

Challenges in portable RF transceiver design

As wireless products such as cellular phones become an everyday part of people's lives, the need for higher performance at lower costs becomes even more important. Overcoming the challenges involved in the design of radio-frequency (RF) transceivers can help meet this need. This article provides an overview of RF electronics in portable transceivers and describes design issues as well as current work toward achieving both high performance and low cost. To understand the implications in the design of RF integrated circuits (ICs) we look at the properties of the mobile communications environment. We then study receiver and transmitter architectures and their viability in present IC technologies. An example of an RF transceiver is given and the design of transceiver building blocks is discussed. We conclude by looking at future directions in RF design