一种准同步CDMA无线接入系统

A Quasi-Synchronous CDMA Wireless Local Loop

描述了最新研制的一种实际的准同步CDMA频分双工无线接入系统 ,它可提供话音和数据业务 ,也可作为专用的无线数字通信网。工作频段为 1. 9GHz,每个基站的无线覆盖距离可达 30km。介绍了时分复用码分多址空中接口和上行信号闭环延迟控制两项关键技术 ,分析了同步精度对比特误码率的影响。系统采用了基于误码率测量的闭环功率控制技术 ,效果良好。给出了评估和现场实验的结果。

This paper describes a practical quasi-synchronous CDMA frequence division duplex wireless local loop which provides basic services of voice and data or is used as special wireless data network. Every base station in the system provides coverage range up to 30km using the 1.9GHz carrier frequncy band. Both the air interface based on time division multiplex CDMA and the uplink synchronization techniques based on closed loop delay control are introduced. The influence of synchronization accuracy on bit error rate is analyzed. The closed loop transmission power control based on measuring BER is adopted in the uplink and shown to be effective. Finally, the results of evaluation and field experiments are presented.