Design And Implementation Of UQPSK Modem Based On AD9361

With the rapid development of UAV industry in recent years,its application scope and demand have increased significantly.From the perspective of military reconnaissance,UAVs can achieve high-resolution image acquisition,but satellite remote sensing often can not obtain information because of stratus cloud occlusion.Moreover,UAVs are flexible and low-cost,which can be said to be an effective supplement to remote sensing satellites.Compared with manned aircraft,UAVs can avoid the casualties of aircraft pilots.In the civil field,UAV also plays an important role.It is widely used in disaster relief,video shooting,aerial remote sensing and power inspection.UAV data link system is an important part of UAV application in various fields to determine its performance.Aiming at the function and performance requirements of UAV high-definition image transmission,this paper designs and implements the data link system between UAV and ground station.At present,UQPSK modem technology is widely used in UAV measurement and control system,which benefits from its high spectrum utilization and flexible use.UAV is developing towards intelligent miniaturization.This paper designs and implements UQPSK modem based on AD9361 on FPGA,which has good communication performance and can realize the miniaturization of equipment,and is easy to carry on UAV.The main research contents of this subject include the following main contents: the basic principle analysis of UQPSK modem,the design of UQPSK modem,the development of RF front-end AD9361 and the hardware implementation of UQPSK modem on FPGA.Firstly,the general theoretical knowledge of UQPSK modem is introduced from the principle.Then,according to the actual demand and system design index,the UQPSK modem is designed.The design process of each main functional module is simulated.The time-frequency waveforms of each main part of the signal flow are given.The performance of the designed UQPSK modem is analyzed and simulated,and the correctness of the design is verified.It has a certain guiding significance for the actual implementation of FPGA.Finally,the hardware platform used is introduced,the chip selection is analyzed,and the function and configuration of AD9361 are briefly described.Then the hardware implementation of UQPSK modem is carried out on the FPGA.The realization of transmitter mainly includes the spread spectrum of information,the shaping filter and the LVDS interface.The realization of receiver’s FPGA mainly captures and follows the spread spectrum code.The tracer module,Costas loop module and information demodulation module are described in detail.Finally,the design and implementation of the whole modem are completed.The actual test results meet the requirements of the system design and meet the practical application requirements.