Research On Signal Design And Physical Layer Encryption Technology Of Radar And Communication Integration Based On OTFS

The development of Internet of vehicle technology is in the ascendant.The integration of radar and communicatio,which means that a set of equipment is used to realize radar detection and communication transmission to ensure the safe driving of vehicles,has become one of the hot spots in the current research of Internet of vehicle.Compared with single radar or communication equipment,it not only helps to reduce space and save costs of equipment,but also can maximize utilization of limited spectrum.According to the current situation of Internet of vehicle and the characteristic of high mobility of vehicles,this thesis proposes to apply orthogonal time frequency space(OTFS)technology to design radar-communication integrated signal,which is suitable for the high-speed environment and try to improve communication performance and ranging ability.Also,the feasibility of this technology is analyzed.Then the physical layer security technology is used to design integrated signal to provide security for transmitted information of military vehicles.The main contributions are as follows.(1)Performance of radar-communication integrated waveform of OTFS based on pseudo-random sequence.Aiming at the special scenes with dense vehicles,this chapter uses pseudo-random sequences to spread spectrum and bit error rate is improved by 20dB.Through using pseudo-random sequence for preprocessing symbols,the auto-correlation of symbols in time-frequency domain is improved,and the cross-correlation is reduced,thereby reducing the impact of symbols on the performance of the integrated signal.Compared with original integrated signal,maximum distance sidelobe value is reduced by 10dB.The radar ranging performance of this signal is improved.(2)Physical layer encryption scheme based on integration of radar and communication.Due to the special environment of Internet of Vehicle,information is transmitted through open channels,which cannot guarantee the reliability of information sources,and is easy to be eavesdropped,leading to the leakage of legitimate user information.In this chapter,physical layer key is combined with radar detection information to encrypt the integrated signal to ensure trusted communication between users.The simulation results show that this scheme can guarantee the security of communication,and keep BER performance unchanged.The ambiguity function of the improved integrated signal presents a pushpin shape and maximum distance sidelobe value is reduced by 2dB,which has better detection performance.