中文摘要：

该文针对2维DOA估计运算量大的问题，提出一种改进的降维MUSIC（MRD-MUSIC）算法。MRD-MUSIC算法利用二次优化方法将2维DOA估计分解为两级1维DOA估计，从而大大降低了运算量。其中采用对优化函数直接求导的方式求解问题函数，使方向向量得到了较强约束，因此求解结果更加接近最优解。仿真实验验证了算法的正确性，角度估计运算效率高，无角度配对过程，且具有较高的成功率与精确度。

英文摘要：

This paper proposes a Modified Reduced-Dimensional MUSIC （MRD-MUSIC） Direction Of Arrival （DOA） estimation algorithm to solve the computation-intensive problem in the two-dimensional DOA estimations. The MRD-MUSIC algorithm can distinctly reduce the computational load, since the two-dimensional DOA estimation can be decomposed into two stages of one-dimensional DOA estimations by the quadratic optimization method. In this algorithm, a one-dimensional DOA is obtained by the direct derivation of the quadratic optimization function, and the steering vectors are strongly constrained in the solving process, as a result, the derivation is closer to the optimal solution than the other’s. The simulation results verify that the theoretical derivations of this algorithm is of correctness, it does not need pair matching processes, and it has higher successful rate and precision of the angle estimation.