Method of designing anti-Doppler lower pair petal waveform

[0033] The design method of the anti-Doppler low sidelobe waveform of the present invention will be further described in detail below.

[0034] Fig. 3 shows the flow process of a kind of design method of anti-Doppler low sidelobe waveform of the present invention, according to this flow process, the specific steps of this embodiment are as follows:

[0035] Step S1: Initialize i=0; generate a random signal A with Gaussian distribution i (τ)(τ>=0), take the interference signal r i (τ)=A i (τ)(τ>=0), r i (τ)=-A i (-τ)(τ<0), where i=0, 1, 2, ...;

[0036] Step S2: The interference signal r i (τ) is arithmetically added to the frequency (β*τ) of the chirp signal to obtain an improved spectral component F i (τ);

[0037] Step S3: Calculate the time-domain waveform S of the improved chirp according to the following formula i (t), i=0, 1, 2, ...

[0038] S i ( t ) = e j 2 π ∫ - t t f ( βτ , r ( τ ) ) dτ - - - ( 4 ) ;

[0039] Step S4: Calculate the time-domain waveform S of the improved chirp according to formula (3) i (t) autocorrelation waveform R i (τ), and through the method of mathematical extremum, calculate R i (τ) the highest sidelobe value P i , i=0, 1, 2, ...; (if it is the first time to get P i value, then i=0, if it is the second time to get P i value, then i=1, and so on. )

[0040] Step S5: Judging P i Whether the value is less than the specified threshold-40dB, if not, then enter step S6, if so, then enter step S8;

[0041] Step S6: Judging whether the specified number of cycles has been reached, if yes, proceed to step S7, if not, return to step S1;

[0042] Step S7: Compare P i value to get the smallest P i value;

[0043] Step S8: Minimum one P i The waveform corresponding to the value is the best waveform.

[0044] According to the optimal waveform obtained by the above design method, the real part of the waveform function is shown in Figure 4, and the imaginary part is shown in Figure 5. The autocorrelation effect diagram of the optimal waveform is shown in Figure 6, in which the first sidelobe of the autocorrelation waveform reaches -41dB. The autocorrelation effect of the optimal waveform under the influence of the 10 kHz Doppler frequency shift effect is shown in Figure 7, which shows that the first sidelobe of the autocorrelation waveform reaches -39dB. The optimal waveform is not sensitive to Doppler effect, but also has the characteristics of very low autocorrelation sidelobe.