全球继电器市场波澜不惊,无线应用开始发力

全球市场整体消费情况2004年全球机电(EMR)、固体(SSR)及高频/微波继电器市场预计为39亿美元,至2007年,年均增长率将近4.2%。2003年下半年和2004年上半年销售额增长率平均为10-15%,而一些公司表示对于一些特殊产品类别反弹性增长更是高达25%-30%。不过,供应商不看好这些产品的长期的增长率。未来3-5年OEM预计其继电器的年均用量将增长3-4%,这在部分程度上是基于全球经济缓慢恢复。VDC(投资发展公司)预测2007年继电器总消费额将达44亿美元,图1示出了全球继电器消费额增长趋势。2003年机电继电器(EMR)、固体继电器(SSR)及高频(RF)继电…     

全球继电器市场回顾

全球市场状况据美国VDE公司统计,2002年全球继电器销售额由于汽车、家电、HVAC(保暖、通风和空讯)、工业控制等市场明显复苏,比2001年(46.58亿美元)增长1.16%,为47.12亿美元。从产品类型构成比例来看,PCB(印制电路板)安装EMR(电磁继电器)仍占全球继电器销售额主要比例(50%以上),SSR固态继电器虽目前占的比例还不高,但其增长速度最快。其它类型继电器市场趋于平缓,且呈下降趋势。从产品应用领域看,通信(占继电器总量25.8%)和汽车(占18.4%)应用几乎占全球继电器市场的一半,其次为工业自动化过程控制。电器及白色家电;自动测试设备;消费…     

全球继电器市场最新动向

2004年国际继电器巨头几乎都增大了在华投资，外商独资化倾向趋强，力图掌控中国继电器产业发展主导权。欧姆龙电子部件（深圳）有限公司二期工程已正式落成，新增40条功率继电器和通信继电器生产线，新增月产能力1550万只。目前总建筑规模已从最初的4万平方米增加至8．7万平方米。2004年公司销售收入达5．82亿元，比2003年猛增64．1％，     

CEVA发力无线市场,关注产品差异化

日前,CEVA在北京召开发布会,CEVA公司市场副总裁Eran Briman先生介绍了公司在无线市场的最近发展以及在多媒体市场的最新产品战略。无线市场飞速发展作为一家DSP IP内核授权厂商,CEVA的市场份额已经超过了80%。在近日举行的发布会上,CEVA公司宣称其客户基带产品出货量超过了高通和Mediatek,在基带市     

Exar新增渠道分销商,全方位发力中国市场

2009年10月30日Exar公司(纳斯达克股票代码:EXAR)在北京举办了Exar渠道签约仪式暨媒体发布会。此举是Exar公司于2009年4月正式收购Hifn以来,在国内媒体和用户面前的首次亮相,也意味着其迈出了在中国渠道战略发展道路上的关键一步。     

MIPS发力无线市场,着眼4G时代

ECDN:得知MIPS获得Mavrix的便携式媒体处理器订单,这对MIPS在便携式市场有着重要意义,尤其现在中国正大力推动以TD-SCDMA为代表的3G市场.而据了解,ARM在手持设备市场一直占有比较大的市场,能否请您介绍一下MIPS在便携式市场领域的市场、及产品战略? MIPS如何抓住3G以及未来的4G市场?     

全球继电器市场发展态势

2004年全球机电（EMR）、固体（SSR）及高频／微波继电器市场预计为39亿美元．至2007年，年均增长率将近4.2％。2003年下半年和2004年上半年销售额增长率平均为10％～15％，而一些公司表示对于一些特殊产品类别反弹性增长更是高达25％～30％。不过，供应商不看好这些产品的长期增长率。未来3—5年OEM预计其继电器的年均用量将增长3％-4％．这在部分程度上是基于全球经济缓慢恢复。VDC（投资发展公司）预测2007年继电器总消售额将达44亿美元。     

中兴通讯挥戈网络市场渠道分销领域

中兴通讯继今年5月正式宣布进军网络市场渠道分销领域之后,又于近日在北京召开题为“中兴网络,中国力量”的产品发布会,旨在通过“广而告之”其高性价比网络产品和个性化解决方案,招募更多的渠道合作伙伴。作为“蓝色数据行动”全国巡展的一站,在本次发布会上中兴通讯详细介绍并现场展示了其具有自主知识产权、性价比极高的网络产品及个性化解决方案。另外,中兴通讯还对外宣布了他们在网络市场的战略部署:坚决进军渠道分销领域,完全放弃直销,全力支持合作伙伴开拓行业市场,倾力打造的特征指纹——强大的自主研发能力、全系列的产品线、个性…     

Broadcom面向中端手机无线应用市场再发力

在手机的发展过程中，许多应用逐步渗透到手机之中。随着手机、便携式多媒体设备技术的不断进步，越来越多的应用开始汇聚，随之而来的就是各种相关应用的无线技术也开始大规模部署在这些设备中。     

全球继电器近期发展态势

市场现状 在经历了2001年的小幅下滑之后,2002年世界继电器市场开始缓慢复苏,2002年世界继电器销售额为47.12亿美元,比2001年的46.58亿美元微增1.16%.     

无线协作中继技术综述

无线协作中继技术具有低成本、扩大覆盖范围的作用,可以有效提高通信系统的可靠性和传输速率。本文对无线协作中继技术进行综述,主要讨论了协作中继的基本协议,并对协作中继的选择方案进行了比较分析。     

Trans-Modulation in Wireless Relay Networks

In this letter, we consider the trans-modulation design for the decode-and-forward relay networks. We propose to reassign the constellation points at the relay nodes to minimize the symbol error rate (SER) at the destination node. The proposed trans-modulation scheme can significantly improve the system SER performance without increasing the complexity of the system, especially when the relays are close to the source. For this case, improvements of about 2 dB for 16-QAM constellation and about 3 dB for 64-QAM constellation are achieved for the single-relay case.     

便携式电子热销,OLED派上大用场

电子制造业正在越来越多为消费类电子产品市场所驱动,而个人数字便携式设备如手机、MP3播放机、蓝牙耳机、数码相机等产品持续畅销是电子制造业所鲜见的,技术融合更加剧了这些产品中集成更多功能和特性,但这些领域一个永恒的发展趋势是个性化明显,消费者热衷于更佳的显示效果、     

Rateless Coding for Wireless Relay Channels

We propose a novel coding framework for wireless relay channels based on rateless codes, which allows for a natural extension to multiple antenna and multiple relay settings. The relaying protocol is half-duplex, and relays independently choose when to collaborate, if at all. With a simulated fountain code based implementation of this framework, we show that the use of rateless codes is both robust and efficient when the channel state information is not available at the transmitters     

中继未知任何信道信息条件下中继选择的研究

由于信道情况差的中继对协作贡献小,且消耗额外的能量,基于某种标准选择出一个或者多个好的中继参加协作,可以提高协同通信系统性能,所以中继选择是协同通信系统的研究热点。针对一个发送端、接收端及每个中继都配置单根天线的无线中继网络,在假设发送方不知道信道信息而接收方已知全部信道信息前提下,本文提出了中继未知任何信道信息时的中继选择方案。首先提出基于信噪比最大的单中继选择方案,推导了单中继选择的成对错误概率表达式;其次提出基于中继排序方法的多中继选择方案,推导了选择2个中继的成对错误概率的下界;最后给出了仿真结果。理论与仿真结果都表明,中继未知任何信道信息的情况下,选择2个中继参加协作的系统错误概率却高于单中继选择。      

Diversity Analysis of Relay Selection Schemes for Two-Way Wireless Relay Networks

One-way wireless relay networks have recently received a lot of attention due to their ability to provide spatial diversity in fading wireless environment. Moreover, performing single-relay selection is a very attractive method due to its cost effective implementation and superior performance. However, one-way relay networks with the half-duplex signalling suffer from a spectral efficiency loss. To overcome such a drawback, two-way wireless relay networks have been proposed and these are also the networks considered in this paper. The paper analyzes the diversity orders of various relay selection schemes, including the best-relay selection, best-worse-channel selection, and maximum-harmonic-mean selection. The analysis is done for the amplify-and-forward protocol and under the two-step and three-step transmission procedures. In particular, it is shown that full diversity orders of R and R + 1 can be achieved in a R-relay wireless network with the two-step and three-step procedures, respectively. Numerical and simulation results are provided to verify our analysis.     

无线中继网络中的物理层网络编码

针对无线中继网络中物理层网络编码技术的应用,分析验证了其所带来可观的吞吐量性能提升。总结了当前物理层网络编码技术的相关研究方向,归纳了通信理论研究、信息理论研究和网络理论研究三个方面。介绍了物理层网络编码的关键技术,对物理层网络编码技术在实际信道条件下的性能分析及改进、采用高阶调制时的检测模糊及改进、基于嵌套格码的计算-转发策略和结合缓冲中继协议设计进行了深入探讨。以期放宽物理层网络编码对信道模型的限制,拓展其适用条件,同时在保障通信过程可靠性的前提下充分发挥该技术对通信有效性的提升,从而推进物理层网络编码技术在实际无线中继通信系统中的应用。     

Cooperative Relay Service in a Wireless LAN

As a family of wireless local area network (WLAN) protocols between physical layer and higher layer protocols, IEEE 802.11 has to accommodate the features and requirements of both ends. However, current practice has addressed the problems of these two layers separately and is far from satisfactory. On one end, due to varying channel conditions, WLANs have to provide multiple physical channel rates to support various signal qualities. A low channel rate station not only suffers low throughput, but also significantly degrades the throughput of other stations. On the other end, the power saving mechanism of 802.11 is ineffective in TCP-based communications, in which the wireless network interface (WNI) has to stay awake to quickly acknowledge senders, and hence, the energy is wasted on channel listening during idle awake time. In this paper, considering the needs of both ends, we utilize the idle communication power of the WNI to provide a Cooperative Relay Service (CRS) for WLANs with multiple channel rates. We characterize energy efficiency as energy per bit, instead of energy per second. In CRS, a high channel rate station relays data frames as a proxy between its neighboring stations with low channel rates and the Access Point, improving their throughput and energy efficiency. Different from traditional relaying approaches, CRS compensates a proxy for the energy consumed in data forwarding. The proxy obtains additional channel access time from its clients, leading to the increase of its own throughput without compromising its energy efficiency. Extensive experiments are conducted through a prototype implementation and ns-2 simulations to evaluate our proposed CRS. The experimental results show that CRS achieves significant performance improvements for both low and high channel rate stations     

Cooperative Connectivity Models for Wireless Relay Networks

This paper considers the ways that cooperating terminals can be connected to each other in wireless relay networks and the constraints imposed by the availability of different system resources. A framework is developed that exposes the relationship between constraints on available system resources and the achievable combinations of communication links between cooperating terminals. Cooperative connectivity models defined by the achievable combinations of links are derived, associated with their minimum cost constraint sets, and mapped to diversity techniques presented in the literature. The constraints considered are the available number of orthogonal relaying channels, the ability of terminals to diversity combine signals on a single common channel, the ability of terminals to diversity combine signals on orthogonal channels, the ability of terminals to transmit signals on multiple orthogonal channels, and the ability of terminals to cancel the effects of interhop interference.