摘要
随着全社会的数字化转型,空天地一体化信息网络被迅速布局,对卫星间的多调制格式的高速相干光通信和高精度测距的需求愈加迫切。基于相干光通信,提出了一种低成本、低复杂度、高精度的通信/测距一体化系统,通过在相干光通信系统中间隔插入特定的测距数据帧,并利用改进的并行数字时钟恢复(CDR)算法,由其中的鉴相模块提取相位偏差信息,无需消耗额外的硬件资源即可实现高精度测距,由此满足卫星上低功耗、低重量和小尺寸的需求。此外,该系统可兼容不同相干光调制格式,包括OOK、BPSK和QPSK以及不同传输速率的相干光通信链路,体现出了高兼容性。提出的系统在现场可编程门阵列(FPGA)上进行实验验证,在625 Mbps和1 Gbps的BPSK信号下进行通信/测距实验。实验结果表明,码元持续时间为1.6 ns和1 ns,测距精度达到码元时长的2.25%和4.74%,测距精度分别为11 mm和14 mm,达到亚码元量级。通过所提出的通信/测距一体化系统,解决了现有测距系统通用性较差,复杂度较高的问题,提升了系统的灵活性。
Objective Currently,the industry has begun to study the next-generation mobile communication technology(6G),which physically divides the space-air-ground integrated network into three parts of satellite,high-altitude platform,and ground mobile communication network.Low Earth Orbit(LEO)satellite communication network has the advantages of wide coverage,long transmission distance,and large transmission capacity,which makes LEO communication network an indispensable part of the space-air-ground integrated network.Coherent optical communication is suitable for free-space laser communication between LEOs due to its advantages of longdistance transmission and flexible modulation and demodulation.At present,BPSK,QPSK,DP-QPSK and other coherent optical modulation formats are commonly used in laser communication between satellite networks to meet the multi-rate adjustable scenarios.In addition,laser ranging is a particularly important application of laser communication,which provides accurate and valuable information for ground navigation and earth observation.Considering the satellite payload and power consumption,how to achieve high-speed laser communication between satellites and a highly compatible communication/ranging integrated system that can complete accurate ranging is of great significance to the next generation of large-capacity inter-satellite information networks.Methods An integrated system for communication and ranging at the sub-symbol level is proposed(Fig.1).Since the digital clock recovery algorithm can output the frequency and phase offset within the symbol,ranging between the transmitter and the receiver can be achieved by extracting the phase deviation from it.The scheme realizes sub-symbol level ranging without interrupting the normal communication mode(Fig.2).Compared with other ranging schemes,this system does not require additional complex algorithms or hardware.The scheme keeps the ranging data frames aligned with integer seconds by inserting specific ranging data frames and transmits an intege
作者
翟政豪
王宜州
黎景
王亮
戴潇潇
刘陈
杨奇
ZHAI Zhenghao;WANG Yizhou;LI Jing;WANG Liang;DAI Xiaoxiao;LIU Chen;YANG Qi(School of Optical and Electronic Information,Huazhong University of Science and Technology,Wuhan 430074,China;Jinyinhu Laboratory,Wuhan 430040,China)
出处
《红外与激光工程》
EI
CSCD
北大核心
2024年第8期186-193,共8页
Infrared and Laser Engineering
基金
国家重点研发计划项目(2022YFB2903403)。
关键词
FPGA
时钟恢复
高精度测距
相干光通信
FPGA
clock recovery algorithm
high-precision ranging
coherent optical communication
