光接入系统 meaning in English

oas optical access system

Then we introduce the character of the atmosphere channel , which we emphasized on the atmosphere scatter , absorption and scintillation ' s effect on the laser beam . in chapter , we explain why we used cassegrain telescope to collect the optical signal at first , then the lightsource , detector , front amplifier used in optical communication has been compared to that of fiber communication , the noise including shot noise , thermal noise and background light noise has been explained here for analysis the snr and ber in the next section
在第三章介绍无线光接入系统的光收发单元，采用多孔径卡塞格伦式的收发天线对消除减小大气湍流影响有较大作用，针对大气信道的特点无线光系统收发单元在光源、光探测器、前置放大电路上存在许多有别于光纤通信的技术，同时还阐述了光接收机包括背景噪声的噪声机制和接收灵敏度、误码率等指标，最后给出了一个整个传送链路的功率预算。