A Statistical Theory of Mobile-Radio Reception

TLDR

The statistical characteristics of the fields and signals received by a moving vehicle are deduced from a scattering propagation model. The model assumes randomly phased azimuthal plane waves incident on the receiver antenna and compares theoretical predictions with experimental results wherever possible. Amplitude and phase distributions, spatial correlations, and a direct link between the signal amplitude spectrum and the product of incident plane waves’ angular distribution and antenna gain are derived; coherence of signals depends on the distribution of relative time delays, with coherent bandwidth inversely proportional to delay spread; experimental agreement confirms the model’s validity and improves when nonstationary effects are considered.

Abstract

The statistical characteristics of the fields and signals in the reception of radio frequencies by a moving vehicle are deduced from a scattering propagation model. The model assumes that the field incident on the receiver antenna is composed of randomly phased azimuthal plane waves of arbitrary azimuth angles. Amplitude and phase distributions and spatial correlations of fields and signals are deduced, and a simple direct relationship is established between the signal amplitude spectrum and the product of the incident plane waves' angular distribution and the azimuthal antenna gain. The coherence of two mobile-radio signals of different frequencies is shown to depend on the statistical distribution of the relative time delays in the arrival of the component waves, and the coherent bandwidth is shown to be the inverse of the spread in time delays. Wherever possible theoretical predictions are compared with the experimental results. There is sufficient agreement to indicate the validity of the approach. Agreement improves if allowance is made for the nonstationary character of mobile-radio signals.