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

Wideband direction-of-arrival estimation using frequency-domain frequency-invariant beamformers: an analysis of performance

“…In this paper, an extension of the work in [1] with an analytic study of performance is presented. We first review the method for wideband DOA estimation using FDFIBs in [1].…”

“…In [3], a derivation for the resolution threshold, at which the beam-space MUSIC is able to resolve two closely spaced sources, has been presented. For wideband signals, recently, new methods for DOA estimation based on beam-space processing have been proposed in [1] and [4]. These methods improve the resolution threshold and reduce the computational complexity, compared with the conventional methods.…”

“…Narrowband DOA estimation method, such as the MUSIC estimator, is then applied in the beam-space at a single selected frequency within the Manuscript bandwidth to estimate DOAs. The frequency invariance of the beamformer can be formed by time-domain processing [4] or by frequency-domain processing [frequency-domain frequency-invariant beamformers (FDFIB)] [1]. In [1] and [4], only simulation results (without analysis) are presented.…”

“…We first review the method for wideband DOA estimation using FDFIBs in [1]. The MUSIC estimator is used in combination with the method.…”

Robust Noise Filtering in Wideband Frequency-Invariant Beamforming with Uniform Circular Arrays

“…In our previous work on spatialtemporal channel sounding in the 2-8 GHz spectrum [3] and on UWB standalone location systems [4], we chose to implement the uniform circular array (UCA) over the uniform linear array (ULA) due to the following main advantages [5], [6], [7], [8], [9]: 1) the azimuth of the UCA covers 360 • in contrast to 180 • ; 2) the beam pattern of the UCA is constant around the azimuth angle while that of the ULA broadens as the beam is steered from the boresight; 3) the UCA offers greater interference rejection for an equivalent number of elements. Despite these advantages, conventional beamforming in uniform circular arrays generates frequency-dependent beam patterns; when synthesized in wideband systems, the resultant sidelobes [10] are relatively large with respect to the ULA and due to their complexity linear methods [11], [12], [13], [14], [15] cannot be used for multipath extraction or sidelobe suppression. Conversely, frequency-invariant beamforming (FIB) achieves a constant beam pattern over any band of operation by transforming the physical-array response into a virtual-array response.…”