Adaptive cross polarization Interference canceler for use at intermediate frequencies

摘要

An intermediate frequency adaptive cross polarization interference canceler for processing an interfering cross polarization signal distorted by dispersion. The canceler has right and left inputs for respectively receiving right and left polarized IF input signals. A plurality of serially coupled complex multiplier and control stages respectively process the right and left polarized signals to provide controlled amounts of coupling between them to cancel cross polarization interference therebetween. A plurality of delay lines add predetermined time shifts to the right and left polarized signals between stages, and which forms a transversal filter having a predetermined number of taps. The canceler outputs right polarized IF output signal and a left polarized IF output signal having substantially no cross polarization interference therebetween. A preferred embodiment of the adaptive cross polarization interference canceler uses a compensating five-tap transversal filter disposed in the cancellation path. A simplified single tap adaptive cross polarization interference canceler may be used if there is no dispersion.