Accession Number : ADA133733

Title :   Research in Adaptive Beamforming for Satellite Communications.

Descriptive Note : Final technical rept. 1 Nov 81-31 Oct 82,

Corporate Author : PENNSYLVANIA UNIV PHILADELPHIA

Personal Author(s) : Haber,Fred ; Bar-Ness,Yeheskel ; Yeh,Paul Chien-Chung ; Bono,Charles

PDF Url : ADA133733

Report Date : May 1983

Pagination or Media Count : 235

Abstract : The results of an investigation of adaptive interference cancelling techniques for use with satellite borne arrays of sensors are presented in the report. 'A Hybrid Array' utilizing both a pointing vector and an internally generated reference is analyzed. The steady state and transient properties of the processor are presented showing speed of response, signal to interference plus noise ratio, and reduced sensitivity to pointing errors over schemes heretofore used. Also developed is the sensitivity to random amplitude and phase error in the pointing vector. A means by which the pointing vector can be obtained utilizing a pilot ground source is described and analyzed. In addition, analyses are presented on improved methods using only an internally generated reference. One scheme is analyzed in which non-oscillatory weights are obtained even when an imperfect reference is generated. This analysis is carried out assuming no interference, paralleling earlier work on a related scheme in which oscillatory weights were obtained. A second analysis is presented on a method which corrects the cause for unstable weights. This analysis is carried out with desired signal, interference, and noise present. (Author)

Descriptors :   *Satellite communications, *Satellite antennas, *Antenna arrays, *Beam forming, *Adaptive systems, Signal to noise ratio, Radiofrequency interference, Cancellation, Algorithms, Hybrid systems, Steady state, Ground level, Detectors, Aiming, Weight, Sensitivity, Velocity, Transients, Response, Errors, Amplitude, Pilots, Oscillation, Reduction, Sources, Internal, Arrays

Subject Categories : Unmanned Spacecraft
      Non-radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE