Research On Integrated Communication And Active-passive Radar System And Key Technologies

Integrated Communication and Radar is a key technology to solve spectrum scarcity,realize spectrum sharing,and improve spectrum efficiency.Based on the background of Integrated Communication and Radar,this thesis designs a new Integrated Communication and Active-Passive Radar system,which can support multiple modes such as point-to-point communication,monostatic active sensing,and bi-static active/passive sensing,and completes the research of system architecture design,waveform design and signal processing.The main work and research results of this thesis include:1.A novel Integrated Communication and Active-Passive Radar(ICAPR)system is designed,which consists of two separate and cooperative communication and radar dualfunction nodes.It can realize point-to-point communication,monostatic/bistatic active sensing and bistatic passive sensing simultaneously by using the integrated multi-carrier OFDM waveform.According to the functional requirements of the system,the system composition structure and system parameters are designed.Furthermore,bistatic geometric relation is introduced into OFDM ambiguity characteristic analysis,and the target detection capability of ICAPR system is evaluated.2.Aiming at the problem of low target bistatic parameter estimation accuracy and communication channel capacity when average power distribution scheme is adopted,a waveform design scheme based on subcarrier power distribution is constructed.The bistatic geometric relation is introduced into the target parameter estimation problem.According to the radar extended target echo signal model,the bistatic geometric relation influenced by the bistatic geometric relation is derived,and it is used as the radar performance index.Under the constraint of total transmitting power,the optimization problem of minimizing CRLB is established,and the optimal radar scheme is obtained.Then,under the constraints of the similarity to the radar optimal scheme and the total transmit power,the optimization problem of maximizing the channel capacity is established and solved by convex optimization.Simulation results show that the design waveform is better than the average power scheme.3.Aiming at the problem that random communication symbols affect the active sensing performance and the quality of reference signal affects the passive sensing crosscorrelation performance,a signal processing scheme of communication-active and passive radar is constructed based on the institutional advantages of ICAPR system.To solve the problem that the communication performance and dual-base host/passive sensing performance deteriorate due to high bit error rate of communication link,a RadarAssisted Communication(RAC)channel estimation method is constructed based on millimeter-wave multipath scatterer channel.The relevant parameters of multipath components are estimated by radar signal processing,and the channel matrix is reconstructed.Compared with the traditional communication frequency domain least square channel estimation method,the RAC method not only reduces the pilot frequency overhead,but also improves the communication bit error rate performance of the system.