Enhanced forward backward spatial filtering method for DOA estimation of narrowband coherent sources

The forward-only filtering approach first suggested by A. Moghaddamjoo (1991) to estimate the direction of arrival (DOA) of narrowband coherent sources is further investigated. The authors propose and analyse an improved method based on the application of a suggested forward/backward spatial filtering scheme of an array vector. They show that this method significantly improves the signal resolution and they prove that their method requires fewer sensor elements than the other filtering approaches. The effectiveness of the proposed algorithm is also proved in the general case of a mixed source scene consisting of fully correlated (coherent) and partially correlated signals, Monte-Carlo simulation experimental results that confirm the analysis are presented as well.