Spectral estimation of space–time signals with a DIMUS array

The DIMUS (digital multibeam steering) technique is a method for processing the output signals of the elements of a receiving array to permit the simultaneous generation of a large number of beams. This paper deals with the estimation of the spectral density of the signal received by a DIMUS array processor. It is shown that there is substantial frequency distortion introduced into the spectral estimate by the finite size of the array. Also the hard clipping which is part of the DIMUS techniques introduces a nonlinear distortion manifested by a filling in of spectral valleys. Techniques for correcting both of these effects are proposed.