DOA estimation of wide-band signals based on time-frequency analysis

A numerical study on an approach based on the time-frequency analysis is performed for the high-resolution direction finding applications of wide-band signals. In this method, the direction of arrival (DOA) is estimated using a subband of the incoming signal instead of the whole signal spectrum. This treatment forces the DOA of the wide-band signals to be similar to that of the DOA of the narrow-band signals. The reason behind this can be thought of as the after effects of reducing the signal bandwidth, which constrains the signal subspace. An empirical analysis of the performance of the DOA estimator is also investigated. This is done to compare the correct and estimated angles of separation between the targets, and it is demonstrated that there is a good agreement which implies that the use of prefiltering does not affect the resolution of the DOA estimator.