南邮研究生专业英语复习资料

ONE

(1)The radio age began over a 100 years ago with the invention of the radiotelegraph by Guglielmo Marconi and the wireless industry is now set for rapid growth as we enter a new century and a new millennium. The rapid progress in radio technology is creating new and improved services at lower costs, which results in increases in air-time usage and the number of subscribers. Wireless industry revenues are currently growing between 20% and 30% per year, and these broad trends are likely to continue for several years.

马可尼在100年前无线电报的发明开启了无线电时代，现在无线电行业的快速增长被认为我们进入了新世纪和新千年的时代。无线技术的快速发展是以较低的成本创造新的和改进的服务，从而增加了在时间上的使用量和用户使用的数量。无线电行业的收入目前每年以20%到30%的速度增长，而这些大的趋势可能会持续几年。

(2) Multiple access wireless communications is being deployed for both fixed and mobile applications. In fixed applications, the wireless networks provide voice or data for fixed subscribers. Mobile networks offering voice and data services can be divided into two classes: high mobility, to serve high speed vehicle-borne users, and low mobility, to serve pedestrian users.

多址无线通信正应用于固定和移动设备。在固定应用中，无线网络为固定用户提供了语音、数据业务。移动网络提供的语音、数据业务被分为两类：高速移动性，为高速车载用户服务；低移动性，为行人用户服务。

(3) Wireless system designers are faced with a number of challenges. These include the limited availability of the radio frequency spectrum and a complex time-varying wireless environment (fading and multipath). In addition, meeting the increasing demand for higher data rates, better quality of service (QoS), fewer dropped calls, higher network capacity and user coverage calls for innovative techniques that improve spectral efficiency and link reliability.

无线系统的设计人员面临着一系列挑战。无线系统的设计人员面临着一系列挑战。此外，满足更高的数据速率的需求日益增加，更好的服务质量（服务质量），更少的掉线问题，以及较高的网络容量和用户覆盖要求创新的技术，这些创新技术能要提高频谱效率和链路可靠性。

(4) Wireless system designers are faced with a number of challenges. These include the limited availability of the radio frequency spectrum and a complex time-varying wireless environment (fading and multipath). In addition, meeting the increasing demand for higher data rates, better quality of service (QoS), fewer dropped calls, higher network capacity and user coverage calls for innovative techniques that improve spectral efficiency and link reliability.

无线系统设计人员面临着许多挑战，这些挑战包括无线电频谱的有限可用性和复杂的时变无线环境（衰落及多径）。此外，需要更好的服务质量，更少的掉线，更高的网络容量和改善频谱效率和链路可靠性创新技术来提升网络容量和用户的覆盖来满足越来越高的数据速率的需求。

(5) The origins of radio date back to 1861 when Maxwell, while at King’s College in London, proposed a mathematical theory of electromagnetic (EM) waves. A practical demonstration of the existence of such waves was performed by Hertz in 1887 at the University of Karlsruhe, using stationary (standing) waves. Following this,