A STATISTICAL CHARACTERIZATION OF POINT-TO-POINT MICROWAVE LINKS USING BIASED RAYLEIGH DISTRIBUTIONS

A recently developed multipath fading model has been used to examine t he characteristics of a point-to-point microwave radio channel. The ne w attributes of this model that differ from other multipath models ena ble the incorporation of the ideas of fading severity and time variabi lity. This is achieved by the use of a biased Rayleigh-distributed sec ond (interfering) ray. The biasing constant determines the fading seve rity, while the Rayleigh cutoff frequency determines the rate-of-chang e of the channel. For point-to-point microwave radio channels, this mo del provides narrow-band fading signal-level distributions that comple tely replicate the Norton or Nakagami-Rice distributions while at the same time providing signal level distributions that replicate those ob tained from broad-band measurements, Thus, this model unifies the narr ow-band and broadband multipath fading models. Using this model, nondi versity and diversity system operation is investigated and the concept of a broad-band correlation coefficient introduced. The distributions of notch speed are also investigated. Software simulation results are compared with some hardware simulation results and field measurements .