改进相关干涉仪算法在DOA估计中的应用

相关干涉仪算法（Correlation Interferometer Algorithm，CIA）是波达方位（Direction Of Arrival，DOA）估计中常用的算法，但是阵列的长短基线导致了该算法在测向中存在基线镜像对称和相位模糊问题.针对以上问题，本文提出了一种基于象限分类的改进相关干涉仪算法.首先，将信号到达各阵元的时间差转化为相位差，同时将得到的相位差与360°作比，记录得到的整数和余数.然后对余数进行象限分类，之后用传统的相关干涉仪算法求解得到信号的初始估计值，最后根据逆运算求解信号的最终估计值.实验仿真表明，该算法不仅解决了基线镜像对称和相位模糊问题，而且提高了信号估计的精度，降低了计算复杂度，提高了测向的实时性.因此在波达方位估计上具有很高的参考价值.

Application of Improved Correlation Interferometer Algorithm in DOA Estimation

The Correlation Interferometer Algorithm (CIA) is commonly used in the Direction Of Arrival (DOA) estimation. But when it realizes the direction finding, the long and short baselines in the array lead to the problems of baseline symmetry and phase ambiguity. An improved correlation interferometer algorithm based on quadrant classification is proposed. First, the time difference of signals arriving at each element is converted into phase difference, as well as the obtained phase difference is compared with 360°, and the obtained integer and remainder are recorded. Then the remainder is quadrant classified, after which the initial estimated value of the signal is obtained by using a traditional correlation interferometer algorithm. Finally, the final estimate value of the signal is calculated based on the inverse operation. Experimental simulations show that the improved algorithm successfully solves the problems of baseline mirror symmetry and phase ambiguity. Moreover, the accuracy of signal estimation is improved, the computational complexity is reduced, and the real-time performance of direction finding is improved. Therefore, it has significant value in the DOA estimation.