摘要
以宽带ＦＤ（ＦｒｅｑｕｅｎｃｙＤｅｐｅｎｄｅｎｔ）模型为基础，讨论了该模型中源真实方位对方位估计性能的影响，指出源方位远离阵法线方向时，估计误差增大，分辨性能下降。通过分析空间协方差矩阵的特征结构，从数学上解释了此现象产生的原因，从而提出聚焦ＦＤ算法（ＦＦＤ：ＦｏｃｕｓｅｄＦｒｅｑｕｅｎｃｙＤｅｐｅｎｄｅｎｔ）作为改进。理论与仿真证明了聚焦的有效性。
Frequency Dependent (FD) model for estimating the direction of arrival (DOA) suffers from the shortcoming that estimation error increases with deviation of source direction away from normal. We present a new FD model: focused FD (FFD) model. Such a model, to our best knowlege, has not been reported in the open literature. We first analyzed the eigen structure of the covariance matrix. We found that estimation error is caused by energy dispersion as shown in Table 1, where θ denotes the deviation angle that the source direction makes with normal, λ i denotes the ith eigen value, ε is the error function. Analyzing Table 1, we put forward a focused FD model (eqs.12, 13, and 14). Simulation results are given in Figs.3 through 6; the solid curve in Fig.4 denotes estimation error of FD model, while the curve with asterisks, that of FFD model. The solid curve in Fig.6 denotes resolution probability of FD model, the curve with asterisks, that of FFD model. These results show preliminarily that our FFD model is better.
出处
《西北工业大学学报》
EI
CAS
CSCD
北大核心
1999年第2期295-300,共6页
Journal of Northwestern Polytechnical University
关键词
宽带
FD模型
方位估计
聚焦
误差分析
信号处理
focused frequency dependent (FFD) model, frequency dependent (FD) model, direction of arrival (DOA) estimation
