Design And Implementation Of LFM Based Sharing Signal For Radar And Communication

Radar systems and communication systems are originally two different systems.One focuses on the detection and tracking of targets,and the other focuses on efficient transmission of information.Both systems play a very important role in military and commercial fields.However,the scarcity of spectrum resources,equipment redundancy,system interference and the similarities between radar and communication systems in some aspects have facilitated the research of radar and communication sharing system(RadComSS).The design of sharing signal aiming to design a suitable waveform,which can simultaneously and efficiently perform wireless communication and detection on one platform,has the highest integration level.Therefore,sharing signal based RadComSS design has become a hot research topic in the field of the fusion of radar and communication system.Under this background,this dissertation mainly focuses on the design of Linear Frequency Modulation(LFM)based sharing signal.First,the basic theory of the RadComSS is introduced.By describing the differences and similarities between the radar and the communication system in detail,the feasibility of integration between the two systems is proved.After that,the working mechanism of the RadComSS,ambiguity function,which is the important detection performance metric of the sharing signal,and the LFM signal are introduced respectively.Then,we focus on the waveform design of the sharing signal.The LFM signal is used as a carrier,and Binary Phase Shift Keying(BPSK)modulation is used to modulate the original communication symbol information to the phase information of the LFM signal to form the LFM-BPSK sharing signal for radar and communication.The processing flow of sharing signal during communication is analyzed in detail,and a feasible solution is proposed for the time and frequency synchronization in the actual communication process.After that,the bit error ratio(BER),from which we can evaluate the communication performance of the sharing signal,is obtained.The ambiguity function of the sharing signal is analyzed,and the distance measurement of single target and multi-target are simulated respectively,so the feasibility of using it for distance measurement has been proven.Finally,a hardware test platform for sharing signal is established through the UniversalSoftware Radio Peripheral(USRP)and relevant software suit.The process of building a test platform is introduced in detail from the hardware equipment and the software experiment platform,and the working process of the test system is determined.After that,Radar ranging and communication transmission experiment have been conducted indoors using coaxial cables,and the performance of the sharing signal is verified.