Coexistence Design Of MIMO Radar Signals

Radar waveform is the carrier of radar system information.The quality of radar waveform directly affects the performance of radar systems.Compared to traditional phased array radars,each array element of the Multiple-Input Multiple-Output(MIMO)radar can transmit different waveforms,that is,it has more degrees of freedom,which can improve the performance of the radar system.With the development of more complex battlefield,simple radar waveform is difficult to meet the actual demand.In order to solve this problem,through the coexistence design of MIMO waveforms in this paper,radar can be equipped with a variety of functions and its resources utilization can be improved.Based on the design of MIMO waveforms,this paper studies the coexistence design between MIMO signals and Linear Frequency Modulated(LFM)signals,and the coexistence design between radar signal and interference signal.The main work can be summarized as follows.1.The coexistence design between MIMO signals and LFM signals is discussed.First,the positive and negative frequency modulated signals are used as a comparison to elicit the method of this paper.An autocorrelation peak sidelobes of MIMO signals,cross-correlation peak sidelobes between MIMO signals and LFM signals and the cross-correlation peak sidelobes between MIMO signals are simultaneously minimized to construct design criteria.Simulation results show that the cross-correlation sidelobes are better than the cross-correlation peak sidelobes between LFM signals of positive and negative frequency modulated ratio In addition,the effects of different sampling rates of LFM signals,LFM signals windowing,different bandwidth or time width and Doppler of LFM signals on the cross-correlation sidelobes between MIMO signals and LFM signals are analyzed.Finally,the design criterion is constructed to minimize the cross-correlation peak sidelobes level between the phase-coded signal and LFM signal in the specific Doppler interval.The phase-encoded signal with certain Doppler robustness is also designed.2.The coexistence design between radar signal and interference signal is discussed.Firstly,the design criterion is constructed by minimizing the autocorrelation peak sidelobes level of a radar signal.Then,the design criteria is constructed by minimizing the cross-correlation peak sidelobes level between interference signal and radar signal,while constraining the energy of the interference signal to design the interference signal.Sequential quadratic programming(SQP)and convex optimization are used to solve the optimization problem.When the interference signal energy is constrained to a fixed value,this is a non-convex constraint,and the objective function will be transformed into a semidefinite programming problem.When the interference signal energy is constrained to a certain range,it is necessary to make each symbol of the interference signal constrained in an interval.In that sense,the constraint is a convex set and the convex optimization tool can be used to solve the problem.Simulation results verify that the correlation between designed interference signal and radar signal can reach to-43.2 d B.