Signal Design And Research Of Integrated Radar And Communication

With the rapid development and progress of modern information technology,the unknowns and challenges faced by combat platforms are also increasing,and more electronic equipment need to be installed to support its combat effectiveness in order to face the increasingly complex modern battlefield environment.The integrated radar and communication system can simultaneously realize radar and communication functions on a set of hardware equipment,thereby improving the resource utilization rate of the system,reducing the problems of electromagnetic compatibility and spectrum interference between equipment,and greatly improving the reliability of the system.In the research of radar and communication integration,it is the main step to design the waveform that can realize both the target detection function and the information transmission function.Therefore,this paper starts from the integrated radar and communication signal design,and considers that the randomness of the communication baseband signal will affect the radar target detection function,the corresponding improvement scheme is proposed for the receiving module of the integrated system.The main contents of the paper are summarized as follows:Firstly,the basic principle of radar and communication integration is introduced.The difference between the radar system and the communication system and the feasibility of realizing the integrated system are explained,and the signal performance evaluation indexes of the integrated radar and communication system are given.The ambiguity functions of typical radar signals,waveform and spectrum of typical communication signals are analyzed and simulated.The design criterions of integrated signal are introduced.Then,based on the integrated signal design scheme of radar common waveform,an integrated NLFM-16 QAM radar and communication signal is proposed.According to the NLFM radar signal and 16 QAM communication modulation,the NLFM-16 QAM signal model is constructed,and the communication-related performance and radar-related performance of the NLFM-16 QAM signal are analyzed respectively,and the information acquisition method of NLFM-16 QAM signal after detecting target is introduced,and the detection of a moving target using the NLFM-16 QAM signal is simulated.The simulation results show that the designed signal of radar and communication integration has high frequency band utilization and good autocorrelation performance,and the ambiguity function graph presents an ideal "pushpin"-like feature,which can realize the distance and speed detection of moving targets.Finally,aiming at the problem that the randomness of the communication baseband signal of the designed NLFM-16 QAM signal will reduce the detection performance of moving target,the receiving end of the radar communication integration system is improved,and the method of wavelet packet noise reduction algorithm combined with blind source separation algorithm is proposed to process NLFM-16 QAM signal arriving at the receiver.In the blind source separation part,natural gradient algorithm and EASI algorithm are adopted.Combined with wavelet packet threshold denoising,noise caused by environment is removed first,and then integrated signal is separated.The simulation results show that the integrated signal output by the improved receiver can detect the same moving target,the dispersion phenomenon of range dimension and the phantom phenomenon of velocity dimension are improved obviously.