深空光通信链路特性分析及功率预算

深空光通信链路距离非常远,要求功率预算非常严格。影响通信链路特性的因素很多,功率预算往往需要很复杂的折中考虑。重点分析了链路距离、光学天线直径、光束发散角、大气信道损耗、光学系统损耗、探测器灵敏度等因素对链路方程、探测器信噪比和通信误码率的影响。提出了结合链路方程、信噪比和误码率对发射功率进行预算的新方法。开展了7 km地面间光通信室外演示验证实验,对大气信道损耗、光学系统损耗等进行了测试;开展了光束发散角、探测器灵敏度的室内测试实验。实验结果和理论分析基本吻合,表明该预算方法具有应用于深空光通信的可行性。

Link Identity Analysis and Power Budget for Deep Space Optical Communications

The deep space optical communication links are very far away, so a very harsh power budget is required. Since there are many factors affecting the feature of communication link, a very complex trade-offs consideration is often given to the power budget. The paper emphatically analyzes the link distance, optical antenna diameter, beam divergence, atmospheric channel loss, optical system loss, detector sensitivity and other factors affecting the link equation, signal to noise ratio (SNR) of detector and bit error rate (BER) of communications. Simultaneously the paper proposes a new method of budgeting transmission power combining the link equation, SNR and BER. An outside demonstration experiment for the ground-ground optical communication of 7km, is carried out, the losses of the atmospheric channel and optical system are tested. Then again many experiments in indoor labs, test the beam divergence and detector sensitivity are performed. The experimental results and theory analysis show that the budget method is feasible in application to the deep space optical communications.