Feature Analysis of Covariance Matrix and Nulls for GNSS Adaptive Anti-jamming Array in Underdetermined Condition

Adaptive anti-jamming array can only suppress partial interferences when received interferences outnumber freedom degree of array, which brings the problem of solving underdetermined linear equation. It gives rise to the influence of unsuppressed interferences on receiver systems. The paper analyzes the eigenvalues and eigenvectors of covariance matrix when multiple interferences lead to underdetermined condition. With simulation experiments, the relationship between features of covariance matrix and nulling properties are revealed. Besides, several constructive suggestions are put forward for anti-jamming processing.