Research On Vehicle-mounted Radar Range And Velocity Measurement Method Based On OFDM Pilot Signal

The radar-communication integration system can realize the fusion of wireless communication and radar perception in the signal level to maximize the spectrum utilization and reduce the complexity of the network nodes.The working frequency and the radio frequency front of circuit structure of the vehicle-mounted OFDM radar-communication integration system become more and more similar to the radar system.The vehicle-mounted OFDM communication signal has the potential to realize the range and velocity measurement of radar.Especially the OFDM pilot signals have the similar feature with the traditional radar signal,the capacity of range and velocity measurement is deserved to research.This paper aims to study the method of range and velocity measurement using OFDM pilot signal in vehicle-mounted communication system.Firstly,the vehicle-mounted radar-communication integration system structure model,send and receive signals model are established.The OFDM pilot signals frequency domain matrix was derived,through analysis the relationship between the range,velocity and the pilot signal matrix based on the matrix,we proposed a method that using the column and row vector to estimate the range and velocity of the target.Secondly,for the problem of the small bandwidth and time width,we must use the MUSIC algorithm to estimate the target range and velocity.However the large computational complexity of spectrum estimation and spectr um peak search Affect the practical when using MUSIC algorithm in vehicle environment.This paper proposes a new method based on MUSIC algorithm to estimate the target's range and velocity.The method using FFT spectrum approximate estimation and search,r educing search domain,and then using MUSIC algorithm accurately estimates.At last,it is necessary to design the structure of the OFDM pilot signal to realize the measurement of range and velocity using OFDM pilot signal effectively.This paper proposes a time-frequency continuous pilot structure which can be used for the measurement of range and velocity by analyzing the relationship between pilot structure and the range and velocity.Simulation results show that the method using pilot signal to estimate the target's range and velocity is feasible in theory,and it has good anti-noise performance.The proposed pilot structure and the proposed method based on the MUSIC algorithm can realize the range and velocity measurement effectively at the same time,and the error is small,and the accuracy is large.The accuracy of range and velocity of the new method is 0.36 m and 0.94m/s,respectively,and it reduces computational complexity compared with the traditional algorithm on the basis of maintaining the estimation accuracy of the MUSIC algorithm,greatly improve the estimation efficiency,it maintain the good anti-noise performance and the high range and velocity measurement precision.