中文摘要：

目标方位估计的克拉美-罗界（CRB）是方位估计方法有效性能评价的标准,它作为任何无偏方位估计方差的下界,给出了目标方位估计方法性能的极限.目前,已有较多的文献研究了窄带目标方位估计的CRB,但还没有研究宽带目标方位估计的CRB.本文提出了水下宽带目标方位估计的CRB.在一定假设条件下,根据水下阵列样本数据的联合概率密度函数和Fisher信息矩阵,推导得到了宽带CRB的解析表示式,计算了不同信噪比、不同目标方位角情况下的宽带CRB.宽带目标方位估计的CRB为水下宽带高分辨方位估计理论研究和统计性能评价提供了依据.

英文摘要：

The Cramer-Rao bound（CRB）of the directions of arrival （DOA） estimation is a comparative standard for the statistical efficiency of DOA estimators. As the lowest bound of variance, it gives the variance performance limit of every unbiased estimator. The CRB of the DOA estimation of the narrow band sources has been studied in many published papers. However, they have not involved that of the wide band sources recently. The CRB of the DOA estimation for underwater wide band sources was proposed. Under reasonable conditions, an analytical expression for the CRB of the wide band DOA estimation was derived from the joint probability density function of the sampling data of the sensor array and Fisher information matrix. The CRBs of wide band DOA estimation were calculated in the case of the different ratios of signal to noise （SNR） and different bearing angles. The CRB is an important reference to the theoretical analysis and the statistical performance appraisal of the underwater wide band DOA ：estimators with high resolution capability.