Constrained beamformer optimization for antenna arrays
Marcus J. Bronzel, Holger Boche · The Journal of the Acoustical Society of America · 1999
A common problem for hands-free voice terminals and for smart antennas in future mobile communication systems is to optimize the directional response of an array of microphones or antennas in order to enhance the signal-to-noise-and-interference ratio (SINR). Digital beamforming (DBF) algorithms are commonly used for spatial filtering, which effectively results in more benign channel characteristics with reduced interference and delay spread. A new constrained beamforming (CBF) algorithm is presented which allows optimum beam steering and interference cancellation for arbitrarily spaced directions for signals-of-interest (SOI) as well as for interfering waveforms. The proposed CBF combines the properties of the Bartlett and the Capon beamformer [L. C. Godara, ‘‘Application of antenna arrays to mobile communications, Part II: Beam-forming and direction of arrival considerations, Proc. of the IEEE 85, 1193–1245 (1997)] while maintaining minimum power requirements. It is shown that the result can be interpreted as the beam vector representation using special interpolating fundamental functions. [Work supported by BMBF.]