Research On Anti-doppler Waveform Design

With the development of radar detection technology,its application in military reconnaissance,unmanned and other fields is becoming more and more widespread.For example,the high-speed mobility of the target requires increasing radar resolution,which poses new challenges to the design of radar waveforms.On the other hand,with the development of communication technology in millimeter wave and higher frequency bands,the coexistence or even integration of radar communication systems becomes the future development direction in the field of radar and communication.In the doppler shift scenario,waveforms with good detection performance should have good ambiguity function characteristics,which are difficult to be satisfied by traditional radar waveforms.To address these problems,this paper focuses on designing sensing waveforms with good performance.Firstly,a class of sequence sets with low ambiguity zone is constructed based on the interleaving technique.The set of sequences obtained in the literature based on the interleaving method is narrower in the time-shift direction.Meanwhile,the set of shifted sequences used to generate interleaved sequences has constraints.To address the above problems,this paper adapts the interleaving technique to change the low ambiguity zone of the sequence set obtained after interleaving to expand the low ambiguity zone in the time domain direction,and at the same time makes the construction of the set of shifted sequences used for the interleaving technique more flexible.Secondly,the use of complementary sequences in the radar system,while the adjustment of filter weights at the radar receiver can make the radar waveform have zero partials in the local frequency bias range of the ambiguity function,but at the expense of the signal-to-noise ratio.In this paper,the problem of low signal-to-noise ratio is addressed by an optimization method to obtain filter weight coefficients that can eliminate the sidelobe while having a better signal-to-noise ratio.The complementary sequences have the problem of limited length.In this paper,quasi complementary sequence with more flexible length is obtained by optimization method.Finally,in the design of integrated waveforms for radar communication,both doppler effect and complex electromagnetic environment will have an impact on radar detection performance and communication quality.In this thesis,we use the We CAN algorithm to obtain an integrated waveform with doppler resilient,and use the SCAN algorithm to design the integrated waveform under spectral constraints.On this basis,both the spectrum-constrained and doppler-shifted effects are considered,so that the waveform still has the property of doppler resilient in the case of spectrum constraints.