A method for wideband direction-of-arrival estimation using frequency-domain frequency-invariant beamformers

In this paper, we propose a new wideband direction-of-arrival (DOA) estimation method for wideband smart antennas based on Frequency-Domain Frequency-Invariant Beamformers (FDFIB). By appropriately designing the weights for frequency-domain beamformers at different frequencies, the frequency-invariant beam-patterns are obtained. Then beamformers play a role as (wideband) spatial processor transforming signals from element-space to beam-space. After that, the narrowband DOA methods can be applied in beam-space to estimate DOAs. The method is able to operate with arbitrary antenna army and arbitrary wide bandwidth without preliminary DOA estimate. In addition, the proposed method provides low computational time and simple implementation. The performance of proposed method in comparison with conventional wideband methods is illustrated in simulation results.