Digital time-delay beamforming with interpolated signals

摘要

In this paper, a general treatment of digital time-delay beamforming with interpolated signals is given. It covers beamforming for low-pass and band-pass signals, and popular digital beamformer structures are included in this approach. Two different topics are combined in the investigation: the first is reconstruction of complex envelope and analytic band-pass signals from a finite number of samples, the second topic applies the first to digital beamforming. Closed form expressions for the digital interpolation beamformer output and its beam-pattern are derived, and the effect of sampling and interpolation is discussed. Numerical simulations underline the power of the general approach of choosing the right sampling rate and interpolation method to realize digital beamformers with very little distortion of their beam-pattern.