论文部分内容阅读
移动通信是当今通信业中发展最快的领域,前景广阔。移动通信都是通过无线的传输方式来获得移动终端的自由移动能力,即通过电磁波的传递来传播信息。电磁场就好似千万条看不见的“线”连接到各个用户,并随时建立用户与外界的无线通信联系。但是,由于受地形、地物以及传输衰减等因素的影响,某些地区的电磁场无法覆盖到,因而不能为用户提供通信服务,这些地区即成为所谓的无线动通信“盲区”。随着高楼的矗立和蜂窝基站的密布,在一个大楼内的20层以上部分有时会有不同蜂窝基站的信号,强度变化。
Mobile communications are the fastest growing areas in the communications industry with broad prospects. Mobile communication is through the wireless transmission to obtain the freedom of movement of mobile terminals, that is, through the transmission of electromagnetic waves to disseminate information. Electromagnetic field is like ten million invisible “line” connected to each user, and at any time to establish user wireless communication with the outside world. However, due to the terrain, terrain and transmission attenuation and other factors, the electromagnetic field in some areas can not be covered, and therefore can not provide users with communication services, these areas have become so-called wireless mobile communication “blind spot.” With the rise of tall buildings and the dense coverage of cellular base stations, signals from different cellular base stations sometimes change in strength over 20 floors in a building.