一种相位编码信号及其失配滤波器设计方法

A Design Method of Phase Coded Waveform and Its Mismatched Filter

为了解决相位编码信号脉冲压缩后峰值旁瓣电平过高的问题,提出了一种新颖的相位编码信号——宽主瓣相位编码信号及其失配滤波器的设计方法。首先,在给定相位编码信号时宽并且保持信号带宽不变的条件下,通过增加相位编码信号的码元长度来增加优化自由度进而降低其峰值旁瓣电平;然后,给出了宽主瓣相位编码信号的设计准则,并使用基于L-BFGS算法的最小p范数优化算法进行求解;最后,基于该相位编码信号提出了以最小化峰值旁瓣电平和逼近期望的主瓣为准则的失配滤波器设计方法,并使用凸优化算法进行求解。仿真结果表明:在给定相位编码信号的时宽、保持信号距离分辨力不变的条件下,与传统相位编码信号相比,主瓣展宽的相位编码信号峰值旁瓣电平可以降低4.32dB;通过设计失配滤波器的方法,该相位编码信号脉冲压缩后的峰值旁瓣电平可以进一步降低5.94dB。

A design method of phase coded waveform（called phase coded waveform with expanded mainlobe）and its mismatched filter are proposed to solve the problem that the peak sidelobe level（PSL）of phase coded waveforms after pulse compression is too high.More degrees of freedom in optimization process are obtained by increasing the code number of the phase coded waveform under a constant bandwidth at a given time width of the phase coded waveform,and then the PSL is decreased.A criterion for designing phase coded waveform with expanded mainlobe is presented,and the least-pth norm optimization algorithm with the L-BFGS is used as a sub-algorithm to solve the problem.Then,a method of designing the mismatched filter based on the designed phase coded waveform is presented to suppress the PSL and to match the desired mainlobe,and a convex optimization algorithm is used to solve the problem.Simulation results and a comparison with the traditional phase coded waveform show that under the given time width of the phase coded waveform,the PSL of the phase coded waveform with expanded mainlobe is reduced by 4.32 dB.When the method of designing the mismatched filter is used,the PSL of thephase coded waveform after pulse compression is further reduced by 5.94 dB.