Research on Adaptive Antenna Techniques V.
STANFORD UNIV CA INFORMATION SYSTEMS LAB
Pagination or Media Count:
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.
- Electrical and Electronic Equipment