Research On Downlink Data Link Communication Method Of UAV Based On OFDM-DCSK

The UAV downlink is a communication link for UAVs to send information to ground consoles.With the widespread use of UAVs in military warfare,there is a greater need for communication methods with fast transmission rate,strong interception resistance and strong multipath interference resistance to be applied to UAV downlink.Since orthogonal frequency division multiplexing technology has the advantages of high spectrum utilization,fast transmission rate,and strong anti-multipath interference,while chaotic signals have the advantages of high confidentiality and can be copied in large quantities,this paper carries out the research on orthogonal frequency division multiplexing technology and chaotic modulation,which provides a key technology to improve the communication rate and anti-interception capability of UAV downlink data chain,with important theoretical significance and practical value.In this paper,based on the in-depth study of OFDM transmission method and chaotic modulation for UAV downlink data chain,we combine OFDM technology with DCSK modulation and conduct a study for OFDM-DCSK transmission method,and also propose a composite preference sequence based on the traditional chaotic mapping,and verify that the preference sequence has better performance through simulation,and apply the preference sequence to The preferred sequence is applied to the OFDM-DCSK system to improve the performance of the OFDM-DCSK transmission method.In order to further improve the performance of the OFDM-DCSK transmission method for UAV downlink data chain,a method based on the combination of LT codes and improved SLM techniques is investigated to reduce the peak-to-average ratio of the OFDM-DCSK transmission method.The signal generation and reception of the UAV downlink datalink communication system based on OFDM-DCSK are simulated and analyzed in MATLAB environment,and it is verified that the system can send and receive information correctly with good BER performance,and the method of reducing the peak-to-average ratio based on the combination of LT code and SLM technology is also analyzed and verified to have good performance of reducing the peak-to-average ratio.