Research And Software Implementation Of MIMO Radar Cognitive Transmission

As one of the future development directions of radar,cognitive radar has the biggest feature of the closed-loop signal processing system from the radar receiving end to the transmitting end.The system can perceive the environment and target information in real time,adjust the radar transmitting and receiving parameters based on prior information and reasoning,so that the radar can be in the optimal state in various environments.MIMO radar can be used as a carrier to realize cognitive transmission because of its high design freedom at the transmitter.It can flexibly design the transmitting signals of each antenna at the transmitter according to different task scenarios under the premise of fixed array structure and limited transmitting resources.In this context,this paper mainly studies the cognitive transmission based on MIMO radar and its software implementation,including the design of transmission waveform and the optimization method of resource management strategy for guiding waveform design.The main contents of this paper are as follows:1.According to the different array structure of MIMO radar,different design methods of transmit waveform are studied.Firstly,the MIMO radar signal model is introduced,including the related concepts of one-dimensional linear array and two-dimensional area array.Secondly,the orthogonal waveform is designed by minimizing the peak side lobe level,and the influence of the number of array elements and the signal code length on the waveform orthogonality is analyzed.Then,for partially correlated waveforms,the design methods of wide beam for target detection and simultaneous multi beam for target tracking are studied: for one-dimensional linear array structure,the optimal covariance matrix algorithm based on positive semi definite programming and the basic beam algorithm based on low sidelobe are used to design the transmission pattern,and the initial phase of signal is optimized by sequential quadratic programming algorithm to improve the correlation of transmitted signals;For two-dimensional array structure,the design method of transmission pattern based on basic beam and subarray division is discussed.2.Aiming at different task scenarios,the radar resource management method is studied.Firstly,for the moving target with uniform velocity,the time resource management algorithm is studied to minimize the number of radar irradiation by optimizing the target revisit time under the constraint of tracking accuracy.Secondly,for the uniform circular motion target,the algorithm of revisit time optimization is studied under the radar irradiation probability constraint.On this basis,a joint optimization algorithm of revisit time and dwell time based on minimizing beam load is discussed to save radar resources.Finally,the above method is extended to multi-target scene,and the radar resource allocation algorithm is implemented under the constraint of tracking accuracy.3.Aiming at the problem of software implementation of MIMO radar cognitive transmission,the design of MIMO radar cognitive transmission module is realized by using C language.Firstly,the programming environment and the third-party MKL library are introduced.Then,the design process of each sub module of cognitive transmission is analyzed,and the functions and data storage methods involved are described in detail.The correctness of each sub module is verified by comparing with MATLAB simulation.Finally,the cognitive transmitter module is added to the cognitive radar system for joint debugging to verify the correctness and effectiveness of the module.