Performance analysis of broadband adaptive digital beamforming

The bandwidth performance of a broadband adaptive array is investigated. It is shown that, in a linear array with K antennas each followed by a tapped delay-line with L taps using the multifrequency point constraints in the method of minimum variance distortionless response (MVDR), one may get the plateau of wideband (relative bandwidth /spl ges/ 20%) frequency response in signal direction and adaptive nulling of the wideband interference. The authors present a bandwidth controllable signal and interference model for simulation and discuss the frequency point choice of for distortionless response. Curves of array gain and interference attenuation versus interference-to-noise ratio are given, which show the adaptive rejection of interference. It is proved that any full rank transform between tap samples and weights cannot improve the bandwidth performance in MVDR.<>