低距离旁瓣稀疏频谱波形相位编码设计

Phase Coding for Sparse Frequency Waveform with Low Range Sidelobes

雷达系统可通过发射稀疏频谱波形(Sparse Frequency Waveform,SFW)克服同频窄带干扰问题,然而SFW通常具有较高的距离旁瓣,降低了弱小目标的检测性能。针对该问题,该文提出一种设计低距离旁瓣SFW的相位编码方法。该方法以联合最小化波形功率谱密度均方差和距离旁瓣为准则建立目标函数,并提出一种基于快速傅里叶变换的循环迭代算法(Cycle Iterative Algorithm,CIA)求解目标函数获得最优相位编码波形。随后将该方法扩展至多输入多输出(Multiple-Input Multiple-Output,MIMO)雷达,设计一组具有良好自/互相关特性SFW的相位编码。该方法沿着使目标函数非递增的方向搜索,且无需求解共轭梯度,计算复杂度低,可快速设计并更新发射波形。仿真结果验证了该方法的有效性与灵活性。

Sparse Frequency Waveform（SFW） can be transmitted by radar systems to overcome narrowband interferences.However,SFW suffers the raised range sidelobes generally,leading to worsening detection performance for weak targets.To solve this problem,a method to design a phase-coded SFW with low range sidelobes is proposed in this paper.The objective function is constructed according to jointly minimizing the mean square error of the power spectrum density with range sidelobes.The Cycle Iterative Algorithm（CIA） based on Fast Fourier Transform（FFT） is put forward to search for the optimal phase-coded waveform.The proposed method is then extended for Multiple-Input Multiple-Output（MIMO） radar to design a set of phase codes of SFW with good auto-/cross-correlation performances.The presented method searches along the direction making sure the objective function nonincreasing and need not compute conjugate gradient.It has a low computation complexity and can be used to design and update the transmit waveform rapidly.Simulation results demonstrate the effectiveness and flexibility of the proposed method.