Accession Number : ADA133676

Title :   Research on Adaptive Antenna Techniques V.

Descriptive Note : Final rept.,

Corporate Author : STANFORD UNIV CA INFORMATION SYSTEMS LAB

Personal Author(s) : Duvall,Kenneth M ; Widrow,Bernard

PDF Url : ADA133676

Report Date : Sep 1983

Pagination or Media Count : 144

Abstract : Adaptive antennas provide an important means of enhancing signal-to-noise ratio in the adverse electromagnetic environments that sometimes arise due to jamming or interference. For that reason, adaptive antennas are increasingly finding application in high performance radar and communications systems. In many of these systems the adaptive subsystem must exhibit robust performance in the face of multipath or rapidly changing interference. Unfortunately, the adaptive beamformers now in use do not perform well in certain environments. It has been known for some time that correlated-signal conditions (e.g., due to multipath) can lead to partial or total cancellation of the desired signal within an adaptive beamformer. More recently it has been recognized that signal cancellation can arise during high-speed adaptation even though (1) the desired signal and interfering signals are uncorrelated and (2) the look-direction response is rigidly controlled. The initial sections of this report examine the signal cancellation mechanism, with emphasis on the more difficult uncorrelated-signal case. Simulation results are presented that illustrate the cancellation effect, and an analysis is given for a simple environment consisting of the desired signal and one jammer.

Descriptors :   *Adaptive systems, *Antenna arrays, *Antijamming, *Beam steering, Jamming, Communication equipment, Cancellation, Spread spectrum, Electromagnetic environments, Low strength, Multichannel, White noise, Algorithms, Signal processing, Adverse conditions, Environments, Simulation, Processing, Signals, Radar, Antennas

Subject Categories : Electrical and Electronic Equipment
      Countermeasures

Distribution Statement : APPROVED FOR PUBLIC RELEASE