The Research Of LMDS System's Transmission Link

Along with the rapidly developing of wireless communication technique,one new type of wireless communication technique, which is approximate fiber, exploit a new road in broadband access network, that is LMDS(Local Multipoint Distribution Service),LMDS is working in frequency band 24～38GHz,the spectrum which can utilize is above 1GHz. LMDS can provide all kinds of service due to adopting point to point of high capacity microwave transport, support two way voice,data,video service,LMDS can realize the access rate from 64kb/s to 2mb/s,even to 155Mb/s,moreover ,LMDS have high reliability . Therefore, L MDS is named as"wireless fiber". When the frequency is released from Aug 2003,all carriers set up LMDS access network rapidly, in order to provide integrated video/voice/high-rate data. Along with the developing of wireless technique, the broadband access system LMDS will be adopted more and more, we believe that LMDS has a bright future.This paper is divided into 4 chapters. Firstly it gives a brief introduction about the evolution of LMDS and the background of development. Next in chapter 2 it describes the architecture, principle and functions of the whole LMDS system. Then it illustrates the detail design of wireless link transmission environment. Finally it analyses the shortage of current LMDS, and put forward new technique to improve the current LMDS.