Research On Integrated Scheme Of Radar And Communication Based On OFDM

For a long time,as two important applications of modern electromagnetic theory,radar and communication technology have gained rapid development.However,with the increasing complexity of the current electronic countermeasures environment,both in combat applications and civil areas,it is eager to develop highly integrated and versatile system equipment to solve these issues of resource redundancy,large-scale systems and electromagnetic interference,etc.Under such circumstances,the integrated system of radar and communication has attracted attention in the field of radar and communications.It provides solutions for the efficient use and integration of radar and communication systems.The integrated system of radar and communication is to design a system capable of both detection and transmission under the existing system hardware conditions.This paper mainly studies the integrated scheme of radar and communication based on Orthogonal Frequency Division Multiplexing(OFDM),and combines the advantages of OFDM technology in communications and detection to design a rational integrated system of radar and communication.Firstly,based on the analysis of several main working modes of current integration system of radar and communication,the design criteria of integrated signal on sharing mode are given,including the ambiguity function,interception factor and signal peak-to-average power ratio.In addition,for the existing two kinds of integrated system schemes of radar and communication based on LFM signals,this paper analyzes their defects after the research.Then a new integrated scheme of radar and communication based on OFDM is designed.For integrated signal of radar and communication design,by adding DFT pre-coding and IFDMA subcarrier mapping make the peak-to-average power ratio be suppressed,and the envelope is constant.Through the simulation analysis,the characteristics of constant envelope and good ambiguity function of the shared signal are verified.At the same time,the signal processing scheme of radar receiver and communication receiver is given respectively for the integrated system.Especially for radar signal processing,a high-accuracy ranging algorithm that combines coarse estimation with time-domain correlation and accurate estimation with phase measurement is proposed,and combines the two-dimensional search of time and frequency and phase estimation method to achieve high-performance speed measurement.Simulation results show that compared to the current integrated scheme,whether range accuracy and speed accuracy or communication error have been effectively improved.Finally,designed hardware implementation of baseband transmitter using FPGA platform for the integrated system of radar and communication based on OFDM proposed in this paper.First of all,the unit module is divided and FPGA programming is performed for each unit,which mainly includes the main control unit,clock management unit,and all of functional implementation units of the integrated baseband transmitter.Simultaneously,through the ISim platform to test its logic function.Then the FPGA board test is performed to verify the correctness of the circuit design and the functionality of the system design.The test results show that the FPGA design in this paper has basically completed the function of the integrated baseband transmitter and the test results are well.