LPI Joint Radar and Communication Signal Design Based on FBMC-chirp

‍ ‍As advanced passive reconnaissance technology develops rapidly， joint radar and communication signal in multicarrier communication not only requires better radar detection and wireless communication capabilities but must also satisfy the requirements of anti-interception and anti-eavesdropping to improve the survivability and combat performance of the integrated system. The low probability of intercept （LPI） performance of joint radar and communication signals in multicarrier communication has become an important challenge in the research of integrated signals. To address the problems of traditional joint radar and communication signal in multicarrier communication， such as the limited radar resolution performance and the requirements of communication effectiveness and reliability not being simultaneously considered in the design， we study a design method of LPI joint radar and communication signal in multicarrier communication with a minimum loss of the performance of radar and communication under the integrated multidimensional signal framework of subcarrier multiplexing. First， from the perspective of improving the utilization of time-frequency resources， a time-frequency structure of LPI joint radar and communication signal in multicarrier communication is designed based on filter-bank multicarrier （FBMC） technology， which optimizes the power of the communication spectrum block and radar spectrum， respectively. The structure of the communication subcarrier is divided into multiple blocks to reduce the peak-to-average power ratio （PAPR） of the communication signal and improve the LPI performance of the communication subcarrier part. Based on this， the joint optimization model of radar subcarrier power and communication block subcarrier power is established by utilizing the performance metrics of the radar mutual information and the communication channel capacity as the optimization constraints and minimizing the total power of the integrated signal as the optimization objective. In this paper， the optimization model is transformed into a convex quadratic programming problem， and the method of trust region is used to solve the optimization problem effectively. Finally， the results of an experiment show that the designed LPI joint radar and communication signal in multicarrier communication has the ideal performance of radar detection and resolution， better wireless communication performance， and good LPI performance.