Research On Integration Technology Of Space Laser Communication And Ranging

As space laser communication has great advantages in terms of transmission rate,transmission capacity,power consumption and safety,our country attaches great importance to the research and development of space-borne laser communication systems.In the "14th Five-Year Plan" outline,it is pointed out that in the field of information and communication,it is necessary to accelerate the development of digitalization,strengthen the construction of information infrastructure,and emphasize the development of fifth-generation mobile networks(5G)and sixth-generation mobile networks(6G).The sixth-generation mobile networks requires that laser satellite terminals not only meet the function of high-speed communication,but also need to meet the requirements of orbital operation.This puts an urgent demand on laser ranging.The future laser satellite communication needs the technology that can realize the ranging function at the same time without changing the original communication data and modulation format.With the increasing demand in the field of laser communication,it is imperative to research space laser communication technology that takes into account the integration of communication and ranging.Based on the analysis of laser communication and traditional laser phase ranging technology,we proposed and designed an integrated system of space laser communication and ranging based on delta-sigma modulation multi-frequency phase ranging method.Without changing the original communication modulation format,this method can use the time slot of the training sequence or synchronization sequence in the communication transmission signal to design a new training sequence or synchronization sequence containing ranging information to complete the ranging function.The use of delta-sigma modulation technology can eliminate the digital-to-analog converter(DAC)at the transmitting end,and only use low-cost digital input and output(IO)ports to generate a digital signal containing multiple frequency points.This digital signal appears as multiple frequency points in the frequency domain and can be combined as a synchronization sequence with a communication data frame.After digital filtering at the receiving end,the original analog signal can be recovered,and the phase difference information of each frequency point of the analog signal can be calculated to obtain the measured distance and complete the integration of communication and ranging.The designed scheme has been verified by theoretical simulation analysis,and the ranging accuracy is up to 1mm.And on this basis,the overall design plan is proposed,and the corresponding hardware circuit and software design are completed.At the same time,this paper also carried out the system design and hardware test platform construction of the integration of spaceborne laser communication and ranging.The ranging experiment was carried out through the response laser ranging method,and the modulation transmitting circuit and the receiving demodulation circuit are designed by using the highsensitivity direct adjustment and direct detection method.The analysis of the test results of communication and ranging has been completed,and better communication transmission performance has been obtained.