基于空时分组编码的MC-CDMA下行链路合并方案

基于空时分组编码的发射分集技术利用空间和时间分集 ,能有效抗多径 ,增强信道可靠性。将空时分组编码应用到MC -CDMA下行链路中 ,构建了一种新的多载波CDMA系统 (ST -MC -CD MA) ,通过在每个子载波信道中获得空间分集增益来提高系统性能。具体实现时 ,依据传统MC -CDMA信号合并方案 ,提出了ST -MC -CDMA空时译码后相应的四种合并方案。仿真结果验证了这 4种合并方案的优、缺点 ;并进一步证明 :在频率选择性瑞利衰落信道中 ,该系统比采用相同合并方案的传统MC -CDMA有明显的性能改善。     

GSM移动通信手机射频收发系统的设计与实现

提出了一种按照GSMPhase2 技术规范实现的GSM移动通信手机射频收发子系统的硬件方法。该系统采用了当今较为流行的DCR方案,并且支持GPRS应用,可工作在EGSM900和DCS1800双频段上。文中介绍了射频收发子系统的构成和基本原理,描述了系统设计实现的具体过程,为系统设计提供了必要的分析和计算。     

浅谈对“教育是一种服务”观念的认识

把教育对象变为服务对象是教育观念一个根本性的转变.尤其是加入WTO后,教育成为一种服务已是时代的迫切呼唤,一个社会化的、开放的、参与国际竞争的中国教育新格局已经到来,只有具有一流服务的学校和教师,才能成为教育竞争的赢家.     

利用CDMA机制实现小卫星星座控制与通信

本文介绍了小卫星及星座的一些基本情况，分析了CDMA技术的优势，初步探讨了CDMA技术在小卫星测控方面的应用。     

跨文化商务沟通中的非语言交际

跨文化商务沟通中，非语言交际起着举足轻重的作用，占整个交际过程的70％。非语言交际涵盖身势语、商务礼仪以及时空安排；非语言行为在跨文化交际中丰富了文化的内涵，在跨文化商务沟通中体现了人的价值取向和行为准则；非语言行为发挥着独特的社会语用功能。     

宽带抗干扰通信系统的跳频同步研究及应用

本文分析了宽带抗干扰跳频通信系统的抗干扰性能，介绍了跳频同步的多种实现方法，提出了一种较好的组合同步方法，并对这种方法的实现原理作了较详细的论述。     

Performing catharsis: The use of online discussion forums in organizational change

Online discussion forums have been used to both support and resist organizational change. Our empirical study examined how employees in one organization used an online forum to help them deal discursively with changes that they perceived as threatening to their identity. In particular, we found that the postings of one key individual were central in framing the organizational changes in a way that had powerful cathartic consequences for employees’ feelings of anger and loss of face. Paradoxically, however, we also found that such use of the online forum had the contradictory consequence of helping to facilitate the very changes that employees perceived to be problematic.     

Job matching, social network and word-of-mouth communication

Workers can find a job either directly or through personal contacts. From this micro scenario, we derive an aggregate matching function that has the standard properties but fails to be homogeneous of degree one. We show that, when the network size increases, on average, the unemployed workers hear about more vacancies through their social network. However, above a certain critical value, job matches decrease with network size. We then establish existence and uniqueness of the labor market equilibrium and study its properties. Finally, we demonstrate that the decentralized market equilibrium is not efficient because of both search and network externalities.     

基于软件无线电技术的第三代移动通信

简要介绍了软件无线电的概念 ,并较详细探讨了软件无线电在第三代移动通信系统的计算机化、实时操作系统、智能天线和移动终端方面的应用。