零差相干空间激光通信中灵敏度退化机理分析与近散弹噪声极限探测技术

项目名称： 零差相干空间激光通信中灵敏度退化机理分析与近散弹噪声极限探测技术

项目编号： No.91438204

项目类型： 重大研究计划

立项/批准年度： 2015

项目学科： 无线电电子学、电信技术

项目作者： 佟首峰

作者单位： 长春理工大学

项目金额： 400万元

中文摘要： 零差相干探测具有灵敏度高、调制灵活、抗干扰能力强等突出技术优势，使其在高速率、远距离空间信息传输领域具有重要应用潜力。然而，若使空间相干激光通信系统的实际探测灵敏度接近散弹噪声极限，不仅需要解决零差相干探测的本振与信号激光器的位相的可靠锁定和跟踪等核心问题、而且还需充分考虑多普勒频移、空间混频效率等外界因素的不利影响。本项目拟在深入分析高灵敏度零差相干探测、高效率空间混频效率等机理的基础上，重点攻关基于COSTAS环的高稳定零差锁相技术，宽范围、高精度频率捕获技术与多普勒补偿技术等关键技术；搭建空间相干激光通信模拟试验系统，并对重要性能指标进行测试和验证。最终实现通信速率为10Gbps、灵敏度达到－42dBm的优异性能指标。为即将在GEO-LEO星际、GEO-地面等远距离、高速率空间信息传输奠定坚实的技术基础，将给空间信息传输带来跨越式发展。

中文关键词： 空间激光通信；零差相干接收；噪声极限灵敏度；光学锁相环；多普勒频移

英文摘要： Optical coherent detection is attractive for space laser communication links because of its better sensitivity、less vulnerability to bankground 、flexible modulation，especiallly it is well known the homodyne Binary Phase Shift Keying（BPSK） receivers can theoretically obtain maximum sensitivity under shot-noise limited condition,so becomes the focus on space laser communication with highrates and long distance.The realistic model for the performance determination of the homodyne PSK receiver with a Costas loop for long-haul communication is proposed；the receiver sensitivity,linewidths requirements,hybrid efficiency and the power penalties taking into account the laser phase noise ,ASE noise,shot noise of corresponding photodiodes is deliberated; the impact on polarizing、atmosphere turbulence、optical tracking error、Doppler frequency shift is investigated. Whatmore,PSK optical homodyne receiver is developed；phase synchroniczation between the input signal and the lacal oscillator laser was achieved using a Costas-type phase-locked loop；pre-processing of the optical signals to be synchronized was done with a basically lossless six-port 90 degree hybrid；Each one of front ends was implemented by means of a transimpedance preamplifier and by two InGaAs photodiodes operating in a balanced manner.At last,homodyne receiver based on BPSK wil be demodulated with sensitivity of －43dBm at bit rate of 10Gbps under initial frequency offset of ±8GHz simulated as Doppler Shifts due to ralative movement，which will be demonstrated the possibility of future large capacity space communications by the optial link and is expected for the next generation space date relay satellite systems.

英文关键词： Space Laser Communicaiton;Homodyne Coherent Receiver;Shot-noise Limited Sensitivity;Optical Phase Locked Loop;Doppler Frenquency Shift