基于谱峰斜率进行变步长搜索的DOA估计方法

针对经典Capon方法存在计算量和存储量庞大、运行时间长、精准度不高的问题,提出一种低复杂度变步长的搜索算法。该方法首次搜索使用大步长的Capon算法,根据谱峰值确定波达方向(DOA)检测范围并求出其斜率值;然后根据斜率首次小于零确定谱峰在其左侧,记斜率小于零点为P,并从点P-2处开始向右进行变步长搜索;最后进行变步长的迭代逼近,得出期望信号的估计角度。所提方法避免了谱峰穷尽搜索,降低了计算量。仿真实验证明,在相同的信噪比下,所提算法准确性的精准度有近9倍的改善;在不同的信噪比下,所提算法的分辨成功率更高;同时,所提算法的均方根误差均明显优于经典的Capon算法。

DOA Estimation Algorithm with Variable Step-Size Search Based on Spectral Peak Slope

Aiming at the problems of the classic Capon method with huge amount of calculation and storage,long running time and low accuracy,a low-complexity variable-step search algorithm is proposed.This method uses the large-step Capon algorithm for the first search.The detection range of the Direction of Arrival(DOA) determined according to the spectral peak,and the spectral peak slope in this range is obtained.Then,based on the slope being less than zero for the first time,the spectral peak is determined to be on its left,the point where the slope is less than zero is maked as P,and the right-hand step search begins at point P-2.Finally,an iterative approximation of variable step length is performed to obtain the estimated angle of the desired signal.The proposed method avoids the exhaustive search of spectral peaks and reduces the amount of calculation.Simulation experiments show that under the same signal-to-noise ratio,the accuracy of the proposed algorithm is improved by nearly 9 times,under different signal-to-noise ratios,the resolution success rate of the proposed algorithm is higher than that of the traditional Capon algorithm.Moreover,the root-mean-square error of the proposed algorithm is significantly better than the classic Capon algorithm.