1、 毕 业 设 计（论 文） 外 文 参 考 资 料 及 译 文 译文题目： SIMULATION OF A CELLULAR RADIO SYSTEM 蜂窝窝无线通信系统的仿真 说明： 要求学生结合毕业设计（论文）课题参阅一篇以上的外文资料，并翻译至少一万印刷符（或译出 3 千汉字）以上的译文。译文原则上要求打印（如手写，一律用 400 字方格稿纸书写），连同学校提供的统一封面及英文原文装订，于毕业设计（论文）工作开始后 2 周内完成，作为成绩考核的一部分。 1 SIMULATION OF A CELLULAR RADIO SYSTEM taken from Prentice Hall - P
2、rinciples Of Communication Systems Simulation With Wireless Aplications page672-676 1 . Introduction A wide variety of wireless communication systems have been developed to provide access to the communications infrastructure for mobile or fixed users in a myriad of operating environments. Most of to
3、days wireless systems are based on the cellular radio concept. Cellular communication systems allow a large number of mobile users to seamlessly and simultaneously communicate to wireless modems at fixed base stations using a limited amount of radio frequency (RF) spectrum. The RF transmissions rece
4、ived at the base stations from each mobile are translated to baseband, or to a wideband microwave link, and relayed to mobile switching centers (MSC), which connect the mobile transmissions with the Public Switched Telephone Network (PSTN). Similarly, communications from the PSTN are sent to the bas
5、e station, where they are transmitted to the mobile. Cellular systems employ either frequency division multiple access (FDMA), time division multiple access (TDMA), code division multiple access (CDMA), or spatial division multiple access (SDMA) . Wireless communication links experience hostile phys
6、ical channel characteristics, such as time-varying multipath and shadowing due to large objects in the propagation path. In addition, the performance of wireless cellular systems tends to be limited by interference from other users, and for that reason, it is important to have accurate techniques fo
7、r modeling interference. These complex channel conditions are difficult to describe with a simple analytical model, although several models do provide analytical tractability with reasonable agreement to measured channel data . However, even when the channel is modeled in an analytically elegant man
8、ner, in the vast majority of situations it is still difficult or impossible to construct analytical solutions for link performance when error control coding, equalization, diversity, and network models are factored into the link model. Simulation approaches, therefore, are usually required when analyzing the performance of cellular communication links.
