Range And Velocity Measurement Using OFDM Signal In Typical Vehicle Communication Environment

Mobility internet extends the normal internet to vehicle environment in which intelligent transportation system is the most key concept.The infrastructure and vehicle have the ability of both wire communication and environment sensing.The technology of fusion signal can reduce the dependency of wireless network and increase the safety of vehicle.OFDM signal has a great advantage in application of wireless communication and radar fusion system.This paper analysis the radar characteristics of two kind of OFDM signal used in communication scene,and propose corresponding radar signal processing algorithm for each OFDM signal.First,this paper analysis two kind of signal named 24G and 5.9GHz frequency point OFDM signal.The former signal have a large time and band width but weak power,noise is the principal factor.The latter signal have a small time and band width but high power,range and velocity resolution is the principal factor.Second,.It is proved that multiple carry can improve resolution of range and multiple pulse can improve resolution of velocity in theory and numerical simulation.To measure the performance of each kind of algorithm,some indicators,include resolution?precision?main-side lobe and dynamic range has been established.Third,some algorithm for 24GHz frequency point signal are analyzed,then a method named maximum likelihood windowing is proposed to solve the influence of side lobe.Numerical simulation proves that this method can eliminate the side lobe to a large extent in cost of reducing resolution and better anti-nose property,which is suitable for the signal.Forth,since normal algorithm are faced with the poor resolution in deal with the 5.9GHz frequency point signal,some super resolution algorithm,include Prony method,MUSIC method and ESPRIT method are introduced to the signal,which acquire target's information by match each range and velocity after estimate range and velocity independently.Then an algorithm named joint estimation of range and velocity is proposed and the process is given up.Numerical simulation proves this method has best anti-noise property in the four algorithms.