摘要
推导了多源情况下宽带波达分析(DOA)估计的克拉美一罗界(CRB),给出了任意阵列情况下Fisher信息矩阵元素的直接计算公式。将CRB的表达式分成与信号和阵列相关的两部分,深入揭示了CRB的特点和影响DOA估计性能的因素。与信号相关的部分表明DOA估计性能除了与信噪比有关外,还与信号带宽和谱密度有关,当信号在高频部分分布更多的能量时可以获得更佳的估计性能。与阵列相关的部分表明DOA估计结果受阵列几何配置和信号入射方位的影响,不同的阵列会对DOA估计结果产生极大的影响。 CRB的这些特性提供了宽带阵列处理中信号选择和阵列结构设计的一些基本原则。计算机仿真结果验证了理论分析的正确性。
The Cramér-Rao Bound（CRB） for wideband Direction of Arrival （DOA） estimation of multi-source impinging on a randomly distributed array is derived. Non-matrix expressions for the elements of Fisher information matrix are provided for computational convenience. The derived CRB can be divided into two terms, one depends on signals＇ characteristics and another depends on array geometry, and so an insight into theoretical performance of DOA estimation can be provides. The first term shows that the DOA estimation performance not only depends on SNR but also the signal bandwidth and spectral density, thus it can be found that better DOA estimates can be obtained for signals with more high frequency energies. The second term shows that DOA estimates vary with different array geometries and source angles. These properties provide us some useful tip to design an efficient signal and array configuration. Simulation results confirmed the results mentioned above.
出处
《声学学报》
EI
CSCD
北大核心
2006年第2期126-131,共6页
Acta Acustica
