DPT和虚拟阵列相结合的相干NLFM信号的DOA估计

DOA estimation of coherent NLFM signals based on DPT and virtual array

针对无线电通信领域中经常遇到多径传输和反射因素的现象,必须考虑宽带相干信号源的存在。提出一种离散多项式相位变换(DPT)与虚拟阵列变换法相结合的相干非线性调频(NLFM)信号的波达方向(DOA)估计方法,并对其中的算法做了对比、分析和改进。解决了常规MUSIC、ESPRIT算法不能估计宽带信号、相干信号的问题,不仅能更准确地进行DOA估计,而且不损失阵列的孔径,提高了阵元数的利用率。同时还提出了当两个信号源很近的情况下的角度估计算法。仿真实验证明了该算法的有效性。

Concerning the common multi-path transmission and reflection factors in the radio communications, broadband coherent sources must be considered. A new algorithm for the Direction Of Arrival （DOA） estimation of correlation wideband Non-Linear Frequency Modulation （NLFM） signals based on Discrete Polynomial-phase Transform （DPT） and virtual array was introduced. And comparison, analysis and improvement were done on the new algorithm. It can settle the problem of not finding coherent signals in routine MUSIC and ESPRIT algorithm. This approach can more accurately estimate and does not decrease effective array aperture, and it also can improve the utilization of array. Then the angle estimation algorithm of two closely-spaced emitters was proposed. The simulation results verify the correctness and efficiency of the new algorithm.