Landmobile Radiowave Multipaths' DOA-Distribution: Assessing Geometric Models by the Open Literature's Empirical Datasets

Abstract

Geometric modeling" idealizes the spatial geometric relationships among the transmitter, the scatterers, and the receiver in a wireless propagation channel-to produce closed-form formulas of various channel-fading metrics (e.g., the distribution of the azimuth angle-of-arrival of the arriving multipaths). Scattered in the open literature are numerous such "geometric models," each advancing its own closed-form formula of a fading metric, each based on a different idealization of the spatial geometry of the scatterers. Lacking in the open literature is a comprehensive and critical comparison among all such single-cluster geometric-model-based formulas of the arriving multipaths' azimuth direction-of-arrival distribution. This paper fills this literature gap. The comparison here uses all empirical data legibly available in the open literature for landmobile wireless radiowave propagation. No one geometric model is best by all criteria and for all environments. However, a safe choice is the model with a Gaussian density of scatterers centered at the transmitter. Despite this model's simplicity of having only one degree of freedom, it is always either the best fitting model or offers an LSE within one third of an order-of-magnitude as the best fitting model for all empirical dataset of all environments.

Empirical Models of the Azimuthal Reception Angle—Part I: Comparative Analysis of Empirical Models for Different Propagation Environments

“…In the first part of this paper, the main purpose is a comparative analysis and approximation error evaluation of the empirical models for different propagation environments. In [20], the obtained results show that none of the geometrical models provides minimization of the approximation error for all analyzed measurement scenarios. With regard to the empirical models, certain attempts to compare them are shown in [21].…”

“…Presented in [20], a review and evaluation of the theoretical models of PDF of AAOA are the basis for the selection of the measurement scenarios for comparative analysis of empirical models. In this part of the paper, the comparative analysis is focused on scenarios that concern the homogeneous propagation environments.…”

“…Compared to [20], here the set of measurement results is limited to seven scenarios that are described in [21,[42][43][44][45][46]. Out of all unimodal, empirical PDFs that are included in [20], the measurement data from [47] are not contained in this paper. For this case, the correction changing position of transmitter (Tx) is not included in AAOA averaging procedure.…”

“…The application of this measure gives the opportunity to use the results from [20] to compare the empirical models and the best geometrical models against the measured data. LSE minimize is also used as a criterion for matching model parameters to measurement data for the particular propagation scenarios.…”

“…In [20], the comparative analysis of the 2D geometrical models with respect to measurement data for different propagation scenarios is presented. However, this analysis applies only to the geometrical models.…”