Mitigation of broadband coherent interference using subbanding

Two adaptive array architectures for rejection of broadband coherent interference are developed. Both techniques involve uniform subbanding using the discrete Fourier transform (DFT) or non-uniform subbanding using the wavelet transform (WT). In the first approach, adaptation and weight computation is performed independently in each subband, and in the second technique the Frost (1972) constrained LMS algorithm is applied to all subbands in the transform domain. Due to the correlated nature of the jamming signal, spatial averaging is utilized in both cases. The mitigation performance of both algorithms is compared for various scenarios of coherent broadband interference.