Fast-polarization-hopping transmit-diversity to mitigate prolonged deep fades

Fast-polarization-hopping (FPH) transmission-diversity is herein proposed to mitigate prolonged deep-fades at the mobile receiver, e.g., in the indoor propagation environment. Even if the individual multipaths are each sufficiently strong for detection, deep fades may occur due to destructive summation at the receiver. Relative immobility, in indoor communications' of the transmitter and the propagation environment and the receiver, means any deep-fade may last for a very long duration, dropping calls or severing links. By fast-hopping of the transmission-polarization (say, alternating transmission from a vertically polarized dipole-antenna and from a horizontally polarized dipole-antenna - or an "X" oriented dipole pair), the effective propagation-channel becomes diversified among a rapid succession of summation possibilities within the channel-coder's interleaving-depth, without any mechanical movement of the transmitting antennas and without any change to the receiving handset. This scheme, within certain to-be-discussed limits, also produces no transmission bandwidth spreading and is compatible to any signaling scheme or transmission standards. The proposed scheme's efficacy is verified by computer simulations using CINDOOR, a polarization-sensitive indoor wireless-propagation simulation software using ray-tracing.