Dual-Polarized Channel Outages During Multipath Fading

Dual-Polarized Channel Outages During Multipath Fading By T. O. M O T T L (Manuscript received December 8, 1976) A statistical model for outages that occur in a dual-polarized-frequency radio channel during periods of multipath fading is proposed, and an analytical expression for outage time obtained. The model, which results in Rice-Nakagami statistics for the Cochannel interference signal, describes channel outage time as a function of several environmental and radio-system parameters. The formulation obtained allows for efficient parameteric studies to evaluate the importance of these parameters to channel outage time and to examine parameter sensitivity questions. Results of practical significance relative to hardware XPD requirements, maximum hop length, system gain, dependence on geographic environment, and digital terminal performance characteristics are obtained for present 11-GHz QCPSK {quaternary-coherent-phase-shift-keyed) digital radio systems. Estimates of dual-polarized-frequency channel outage time are obtained for a variety of representative system parameter values and compared with expected outage times for a conventional channel. Particular attention is given to the mechanism of channel outages during multipath fading, and several potential means for control and/or reduction of channel outage time are discussed. I. INTRODUCTION 1.1 DPF radio systems Federal regulatory requirements for the channel capacity of an 11-GHz digital radio system are achieved in some short-haul radio systems by a diplex approach that uses each available radio-channel frequency band twice.