Examining the Validity of Rayleigh Distribution Assumptions in Characterizing the Fading Channel at 162 and 793 MHz.

摘要

Wireless communications experience temporal variations in received signal level that are characteristic of the propagation channel. Propagation channel fading at VHF and above is predominantly caused by the complex scattering environment through which the radio waves travel. The techniques used in receiver design to mitigate the effects of fading are well established, but the constraints of limited spectral resources and the insidious characteristics of the propagation environment demand increasingly complex modulation techniques to accomplish this mitigation. To maintain system reliability and usability, receivers must be built to increasingly higher tolerances to cope with propagation-induced errors. This report describes a re-examination of the fading channel. Specifically, it presents a reassessment of the assumptions implicit in the understanding of fading channels. This effort involves the measurement, analysis, and assessment of propagation fading and describes the limitations of classical fading theories when applied to ever more sophisticated modulation techniques.