Unified approach to Cramer-Rao bounds in direction estimation with known signal structures

摘要

When estimating the directions of signals impinging on a sensor array, the use of the information on signal structure, leads to improvement in estimation performance. The Cramer-Rao bounds (CRBs), which are lower bounds on variances of estimation errors for any unbiased estimators, are different with signal structures exploited A general formula for the CRB covariance matrix is presented which allows specific bounds with a known signal structure to be easily obtained. When the incident signals are of amplitude modulation, the CRB with the modulation is first presented using the formula. The general formula provides easy analysis of the CRB for various signal structures on a unified basis.