Key Technologies Of Cooperative Design For MIMO-OFDM Radar With Communication

In recent years,due to the increasing scarcity of available frequency bands,and in order to achieve higher and higher functional requirements and higher and higher cost performance requirements,the need to integrate electronic devices with different functions is increasing.Therefore,both civil and military aspects,the need for radar and communication coexistence,radar communication collaborative design is increasing.At present,the key technologies of radar communication cooperative design mainly focus on the design of system transmitting waveform and the elimination of mutual interference,while orthogonal frequency division multiplexing multiple input multiple output(OFDM-MIMO)technology is widely used in the cooperative design of radar system and communication system due to its own advantages.Therefore,in the research of radar communication cooperative design,MIMO radar and OFDM signal are selected to design the transmitting signal.In addition,an improved beamforming method is studied to avoid the interference of radar system to the communication system through the analysis of related technologies.Finally,the feasibility of the method in this paper can be verified by simulation experiments..The main research work of this paper is as follows: 1.This paper studies the common topology structure of radar system and communication system in reality,and analyzes the necessity of solving the mutual interference between the two systems.The differences and similarities between radar system and communication system are studied,which lays a foundation for the combination of radar system and communication system.Then the MIMO technology,OFDM technology and OFDM-MIMO technology are studied,and the importance of choosing OFDM-MIMO technology for the research of radar communication cooperative design is illustrated.2.This paper studies the basic technology of orthogonal space-time block coding(OSTBC),mainly analyzes how to code the radar signal in OFDM-MIMO system.Then,several signal processing processes in OFDM-MIMO radar are analyzed from the aspects of frequency-domain matched filtering,signal-to-noise ratio operation and signal DOD.3.In order to reduce the mutual influence between the two systems,a new beamforming method which combines the radar parameter index and communication capacity index is improved by beamforming the OFDM-MIMO signal encoded by OSTBC.Then the advantages and disadvantages of the proposed method and the traditional LCMV method are analyzed.Finally,the simulation analysis verifies that the improved beamforming method has excellent performance in the flexibility of array configuration,the performance of both communication and radar,and the simulation of radar echo signal proves that the beamforming method will not affect the performance of radar system itself.