Design Of Chirp Shared Signal And Implementation Based On USRP RIO Platform

With the development of modern information technology,the types and quantities of electronic devices are increasingly used in modern society.Electronic devices using different communication protocols lead to the shortage of available spectrum resources.Moreover,Multiple devices functioned on the modern electronic device platform may interfere with each other,resulting difficulties in coordination with each other.Considering the similarities between the radar equipment and the communication equipment,communication functions can be utilized in the radar equipment to solve the above problems giving the equipment both communication and radar functions.In this context,this paper proposes the application research of radar communication shared signals.Firstly,the state of radar communication shared waveform design was introduced.Common waveform design schemes are divided into waveform multiplexing scheme and waveform fusion scheme: The multiplexing scheme aliases the radar signal and the communication signal at the transmitting end,and uses different signal processing algorithms at the receiving end;The waveform fusion scheme uses the radar signal as a carrier signal at the transmitting end,modulates the communication information onto the radar signal,and processes the shared signal at the receiving end through a corresponding demodulation algorithm.In addition,the sharing scheme is divided into a single and a multicarrier scheme: The commonly used single carrier signal is Linear Frequency Modulation(LFM)signal,which has the advantages of large time-width product,excellent resolution;The commonly used multi-carrier signal is Orthogonal Frequency Division Multiplexing(OFDM)signal,which has the advantages of resisting selective fading and effectively resisting inter-symbol interference.This paper mainly discussed the design scheme of single carrier shared signal based on LFM signal.The implementation of the above various design schemes was then analyzed to understand the advantages and disadvantages of each scheme.The radar and communication performance of the shared signal have been considered when selecting a suitable shared signal design scheme.The design was tested mainly from the mechanism of the signal,bit error rate,spectrum utilization,fuzzy function and other aspects of simulation experiments.The linear frequency modulation-binary phase shift keying(LFM-BPSK)composite modulation signal is selected as the final shared signal design.According to the characteristics of the signal,the radar performance and communication performance of the shared signal were analyzed from two aspects: the modulation phase and the number of modulation symbols.The experimental platform was built based on the general software radio peripheral(Universal Software Radio Peripheral,USRP)platform composed of hardware and software part at last.After eliminating the interference of the experimental environment,the LFM signal followed by LFM-BPSK signal was used to carry out the ranging experiment.The final experimental results were compared with the simulation results,and the difference between actual performance and prediction performance of the signal were analyzed,that is,the error in ranging.The feasibility of the signal scheme design was verified by experiments.Methods for further improvement was proposed for possible problems in this paper.This articleaims to balance the radar performance and communication performance of the shared signals,so that it can be optimized in a specific environment.The results were verified by the actual channel experiment.The modulation phase and the number of modulation symbols in LFM-BPSK signal were modified to achieve the above purpose and the specific values were verified by experiments.