Research On The Transmission Scheme Of Collab-orative Integrated Radar And Communication System

Integration of radar and communication can integrate the functions of radar detection and communication transmission,and has a wide range of applications in the internet of things,unmanned driving and other fields.The collaborative design of radar communication integration can deeply integrate radar and communication in an all-round way,and promote the common progress of the two,becoming an important research direction for future integration development.The Orthogonal Frequency Division Multiplexing(OFDM)signal can be effectively used in the integrated transmission process of radar communication due to its high spectral efficiency,easy implementation,and wide application.Based on the integrated continuous waveform of OFDM radar communication,this paper will focus on the transmission scheme of the collaborative design system,and study its key steps,so as to provide a reference for the further integration of radar and communication.The main work of this paper is as follows:Aiming at the problem of serious deterioration of radar performance caused by the timefrequency error in the self-interference cancellation process,an improved self-interference cancellation scheme in analog domain is proposed.The scheme uses multiplexing radar signal processing modules for self-interference synchronization estimation,and performs time-frequency compensation on the reference signal in the analog domain to realize the synchronization between the reference signal and the received signal.The simulation results show that our improved analog domain self-interference cancellation scheme can ensure that the radar performance of the system is basically not affected by the timefrequency error,and improve the robustness of the system.The scheme can achieve precise synchronization without increasing the hardware complexity at the receiver,and effectively avoid the loss of radar performance caused by self-interference.Aiming at the problem of low performance of the equal power transmitting OFDM-radarcommunication integrated waveform in radar target detection and communication data transmission,an adaptive OFDM-radar-communication integrated waveform optimization scheme based on error metric is proposed.In this scheme,the radar Cramer-Rao lower bound(CRLB)and the communication minimum mean squared error(MMSE)are used as the error metrics to evaluate the radar and communication performance respectively.Under the constraint of limited transmit power,this paper establishes a joint performance optimization model that minimizes the error metric.Due to the comprehensive consideration of radar and communication performance,the combined performance of the waveforms designed is better than that of other schemes.In addition,the radar anti-jamming and robust waveform optimization schemes are proposed respectively according to the joint performance optimization model.The simulation results show that the robust waveform scheme can ensure the optimal joint performance under extreme conditions.