评“基于小波变换的多分辨信号波达方向估计法”

Comments on ‘multiresolution signal direction-of-arrival estimation based on wavelet decomposition’

从信号泄漏和空间模糊的角度出发,详细分析了一种基于小波分解的多分辨信号波达方向估计方法(WD MDoA)并指出其缺陷。WD MDoA方法的基本思路是通过小波变换,把接收的阵元数据在空间上分解成多个子带,然后对每个子带进行波达方向估计。分析表明:对于WD MDoA方法,把接收的阵元数据在空间上被分解成多个子带后,如果某个子带外存在其它来波信号时,对该子带进行波达方向估计会产生虚假估计。因此,WD MDoA方法存在着较大的缺陷,计算机仿真结果验证了这个结论。

In view of signal leakage and spatial phase ambiguity, an estimation method of multiresolution signal direction-of-arrival based on wavelet decomposition (WD-MDOA) is analyzed in detail and its disadvantage is addressed. The main idea of the WD-MDOA is as follows: Using wavelet decomposition, the array signal is divided into different subbands in space, then DOA estimation is made on each subband. However, a false DOA estimation in the subband will occur if there exist other signals outside the subband. So the WD-MDOA has some disadvantage. Computer simulation results demonstrate this conclusion. Moreover, the analyses and the conclusion made clarify some concepts in the field of applying wavelet transform to array processing.