Performance Study Of LFM-based Shared Signal For Radar And Communications

Nowadays,as the increasing of electronic devices in one platform,a lot of problems have arisen.For instance,the consumption of spectrum resources,the interference among signals from different devices,the occupation of space,the scheduling design and the consumption of energy,etc.Radar and communication devices are the main electronic devices and the structures of them are similar,which implies that resource sharing can be achieved through system integration.The integration can reduce mutual interference and equipment volume,thus alleviating the problem caused by excessive electronic equipment.Radar communication shared signal is the main trend of radar communication integration,which refers to the signal that can realize dual functions of radar and communication simultaneously.Compared with other system integration schemes,this method can share radio frequency links,improve hardware utilization,simplify system design and reduce system power consumption.At present,the design of shared signals needs to be solved urgently.In this dissertation,Differential M-ary phase shift keyed Linear Frequency Modulation(DMPSK-LFM)signal and Continuous Phase Modulated Linear Frequency Modulation(CPM-LFM)signal are studied respectively.Our main research contents and results are as follows:In this dissertation,the expressions of power spectral density and in-band energy of two signals are deduced and the problem of out-band energy leakage of two signals is analyzed.Based on this,it is proved that there is a trade-off between out-band leakage and spectrum efficiency of two signals.Then a method to reduce the energy leakage outside the band is proposed and verified by simulation.The ambiguity functions of two signals are deduced and verified by simulation,then the radar performances are analyzed,respectively.Compared with LFM signal,the Doppler tolerance of two signals decreases.Furthermore,the velocity resolution of two signals is the same as which of LFM signal while the range resolution of two signals is higher,which is caused by band spreading.Furthermore,the performance analysis of two signals which can be used for radar communication sharing are presented.The theory and simulation show that the two signals studied can be used as radar communication shared signal.