Research On Integrated Signal Of Radar And Communication Systems

With the development of 5G technology,the information transmission network environment is continuously optimized,and the actual application range of millimeter wave is becoming wider and wider.Millimeter wave is used more and more in wireless communication technology and radar technology,which leads to spectrum conflicts between the two technologies,and whether in the military or civil fields,people are increasingly pursuing the versatility of hardware devices.In order to effectively solve these problems,the integrated design of multiple devices is undoubtedly a good solution.Therefore,the integrated and shared signal design of the two is of great significance.This thesis studies an integrated scheme based on Orthogonal Frequency Division Multiplexing-Linear Frequency Modulation(OFDM-LFM)to share signals.First,by analyzing the OFDM-LFM signal,it is known that the signal has the characteristics of strong resistance to inter-subcarrier interference,resistance to frequency selective fading,and resistance to doppler shift.Then combined with the advantages of Constant Envelope-OFDM(CE-OFDM)technology to suppress the Peak to Average Power Ratio(PAPR),the CE-OFDM-LFM shared signal was optimized and designed.This shared signal can meet the requirements of the integrated design scheme,and the radar performance and communication performance of the integrated signal are analyzed through theoretical derivation and simulation experiments.The simulation results show that,compared with the OFDM-LFM shared signal,the normalized 3D ambiguity function of the integrated signal in this thesis is more in line with the pushpin shape,the speed-distance resolution is better,and the PAPR is reduced and the communication transmission rate is higher.In order to further reduce the peak-to-average power ratio of the CE-OFDM-LFM shared signal,this thesis improves the design of the Residue Number System-Radar Communication Ingegration(RNS-RCI).Through analysis,it is found that the smaller the value of the modulus set element is,the smaller the result of the modulus and superposition of the amplitude of each subcarrier will be,and the lower the PAPR.According to this principle,the modulus set of the existing remainder algorithm is improved,and the modulus set with smaller modulus set elements is designed.The value obtained by the remainder of the modulus set elements is used to represent the amplitude of each subcarrier of the original signal to achieve the purpose of reducing PAPR.On this basis,the PAPR in all the remainder channels is sorted,and the signal with the smallest PAPR is selected for output to further reduce the PAPR.The simulation results show that the RNS-RCI algorithm has a better effect of suppressing PAPR.