基于非线性调频信号的多相序列设计

用相位逗留原理，给出非线性调频信号的设计方法，对其进行相位离散化，产生多相离散相位序列P（n，k），其中n和k为频域窗函数的参数。P（n，k）随着窗函数的不同，具有不同的主副瓣比PSR。对n=2和4，长度为100的P（n，k）信号进行优化设计，给出具有近似最优的PSR的P（n，k）信号。对主瓣宽度进行理论分析，给出理论上的主瓣宽度的计算方法。P4码信号作为P（n，1）信号，虽然具有最窄的主瓣，但具有较高的距离旁瓣。计算机仿真表明：P（n，k）信号具有比P4信号更强的多普勒鲁棒特性。与前两者比较，FRANK码的多普勒性能最差。

Design of NLFM Signal Based Poly-phase Sequence

The stationary phase theory is used,and the design method of NLFM signal is presented in this paper.The method is that phase idscretization is performed,and poly-phase sequence P(n,k) is generated by properly sampling in time domain,where n and k are parameters of frequency domain window function,which are approximations of the energy density function of radar waveform over frequency domain,and have different PSR (peak-sidelobe-ratio) as window function is varied.The optimization design is performed for P(n,k) singal whose length is 100,n=2 or 4,and P(n,k) signal with almost best PSR is given.The theoretical analysis of main lobe beambeamwidth is perfomed,the theoretical calculation method of main lobe beamwidth is presented.AsP(n,1) signal,P4 code has the narrowest main lobe but higher range side lobe.The computer simulation indicates that doppler robust characteristic of P(n,k) signal is more stronger than that of P4 signal.Compared with the above two,doppler characteristic of FRANK code is worst.