Millimeter-wave Lmds Broadband Wireless Access Communication System

Following the development of millimeter-wave integrate circuits in recent years there are large trends in the research of civil millimeter wave technology, especially in the telecommunication and vehicle field. The typical telecommunication application of millimeter technology is Local Multipoint Distribution Service (LMDS) system.The local multipoint distribution service system works in the 10,24,26,28,3l,38GHz microwave and millimeter wave bands. The system is a cellular architecture and the service radius is 2-5 kilometer. The base station is connected to the ATM broadband back-borne. The provided services are PABX/POTS voice, high-speed Internet access and network connection, frame relay, VPN and leased line etc. It has been researched widely abroad such as propagation, system design and manufacturing, service and application, standardization etc., because of its potential market value. In China the research millimeter application lasts many years but no many on telecommunication and it is the start point for LMDS technology. It is therefore meaningful both in technology and market to study the LMDS technology.The main works of the dissertation have been done are:1. The study of system access: based on the resources of Shanghai Telecomm, we set up the test bench for varies services and multi-users. The system structure, typical service, network, frequency allocation and user configuration are studied. The huge data were also collected for the propagation study.2. The develop of millimeter wave LMDS sub-system: The work aims the key technology of LMDS. The IF to 38GHz was separated to L band and millimeter band. The millimeter wave source is composed of constant temperature VCO, microwave multiplexer, millimeter wave harmonic mixer and inject amplifier. The sub-system adopts many E-plane filters, and PHEMT devices are used to guarantee the specification requirements. Thenoise figure is less than 8.0dB, frequency stability≤20ppm, phase noise≤-75dBc / Hz / 10KHz at 37. 2GHz. The phase noise is better than foreign products. The work was supported by Shanghai Science and Technology Committee (item number 002212003).3. The study of embeded wireless WBM for LMDS: The embeded wireless WBM technology is first introduced to LMDS base station and remote user terminal. Upon this technology, the huge maintenance work can be reduced for LMDS terminal. The solution is practical.4. The propagation, rain attenuation and anti-attenuation technology study for LMDS system: The double ray mode is used to analyse the reflection affects to LMDS propagation. The anti-rain attenuation technology is also discussed. The method of lower band link for backup of LMDS is proposed. The coverage predictions for Shanghai and typical regions in China are also provided.The proposals for the future work on LMDS technology are given at the end of the dissertation.