INTERFERENCE CANCELLATION SYSTEM FOR GLOBAL POSITIONING SATELLITE RECEIVERS

摘要

An adaptive polarization cancellation arrangement which nulls out all types of concurrent interference signals received by a Global Positioning System (GPS ) receiver from antenna mainlobe and sidelobe situated sources. The orthogonal ly polarized components of the composite received signal are separated by the receive antenna (5) arrangement and adjusted in the polarization feed adapte r network (7, 9, 15, 17) between the antenna and GPS receiver to optimally cancel components. The antenna and installation arrangement creates a polarization filter relative to interference sources which changes their apparent polarization orientation and supports adaptive discrimination based on dissimilar polarization characteristics relative to the desired signals. The orthogonal received signal components from the GPS satellite constellati on and from interference sources are combined to adaptively create cross- polarization nulls that adequately attenuate interference sources while slightly modifying the GPS received signals. The present network can also improve GPS signal levels and signal to noise ratio by polarization optimization or matching in non-interference environments.