Correlation processing and its use to mitigate the effects of multipath and other interfering signals in antenna ranges

摘要

Correlation processing has previously been used in radio communication systems to measure and characterise multipath environments, but it can equally well be applied to the elimination of multipath effects. The authors review the historical development of the technique in the context of its earlier use, and the background to its implementation as a method of eliminating or at least substantially reducing, the effects of multipath in antenna ranges. Correlation processing, which can be implemented either as a one-step, real-time process or used as a post-measurement option, also suppresses the effects of coherent and non-coherent interfering signals, so that the accuracy of antenna pattern measurement is greatly improved. At centimetre and millimetre wavelengths, it is possible to make accurate measurements in a normal laboratory environment without the need for an anechoic chamber. A simple proof-of-concept practical system is described, and example results are presented to demonstrate the validity of the technique and to compare it with time gating.