A Unified Geolocation Channel Model--Part I (Path Loss)

Abstract

Indoor geolocation systems have emerged and have attracted a wide audience recently. There are three important components that constitute an indoor geolocation system: transmitter, receiver, and indoor channel model. To some extent the primary transmitter design requirements are transmit power and a frequency or a set of frequencies of operation. The receiver is designed to operate at a certain distance from the transmitter and at the same frequency or set of frequencies of operation. Hence, any indoor channel model must take into account these two important design requirements.The indoor channel is perhaps very intriguing because multipath is ubiquitous due to high signal scattering, reflection, and refraction. It is been widely accepted in the literature that the two primary channel effects are: path loss and multipath distribution. First, the path loss model is currently accepted to be a function of the transmitter and receiver geometry and frequency of operation. Second, the most widely used and accepted indoor channel multipath distribution models are Raleigh, Rician, and lognormal. As indicated in the second paper (or part II) the Rayleigh distribution is wider than Rician and Rician is wider than lognormal. This implies that the Rayleigh fading channel is the most severe and Rician fading is more severe than lognormal and lognormal is the least severe channel model. Unfortunately, the dependency of the path factor on the frequency of operation in the context of a unified channel model is overlooked in the literature. Furthermore, there is no agreement on an indoor multipath distribution channel model. Although a unified channel model has not yet been found, in this paper we make a first attempt to present a unified channel model which consists of a unified path-loss model and a unified multipath distribution model.The unified path loss model consists of an approach for linking together the path loss models of the three geolocation systems (macro-outdoor, micro-outdoor, and indoor) with the distance between the transmitter and receiver, , and the frequency of operation, . Although there are several parameters that affect the power loss factor, we consider and as the most important parameters for two reasons. Most of the geolocation systems presented in the literature are based on a direct measure of the time of travel; i.e., distance between the transmitter and receiver. The frequency of these systems varies; hence, the path loss factor varies as well.While unifying the path loss model was to some extent initiated in the literature, unifying the multipath distribution model is currently a silent quest in the literature. It appears that the tendency is to come up with newer and more 32Journal of Geolocation, Geo-information, and Geo-intelligence sophisticated models that would explain the characteristics of the old models. The approach that we present in part II (on in a separate paper in the future) to unify the multipath distribution models is rather simple.The theoretical performance results are validate...

Requirements of a C-CDMA Pseudolite Indoor Geolocation System

“…Since 2007 when this paper was originally presented a lot has occurred [15]. Although, this paper lacked a lot of mathematical background found in [15], it served as the bridge between the research that was initially published prior to 2007…”

Generalized Parabolic Cylinder Function Distribution

“…Once all this work is completed then the analysis of my initial publication on [16]- [27] need to be reworked to consider scenarios valid for GPCFDs.…”

Theoretical Data on Support of a Unified Indoor Geolocation Channel Model

“…The path loss model consists of a relationship of the path gain with the transmitter receiver distance and the frequency of operations. It is suggested [1]- [3] that the path loss gain factor is inversely proportional with the nth power order of the distance between the transmitter and receiver. Typical values of range from 2-6.…”

“…As reported in our investigation the path loss caused by the increase of the transmitter receiver distance is much more severe than the path loss caused by the increase of the frequency of operation. The bottom line here is that we need to design future receivers or propose a signal structure 3 that will account for 40 to 80 dB of signal degradation indoors.…”

“…While the first model denotes the line-of-sight (LOS) value 3 Ditto of the path-loss gain, typically other paths are also observed [1]- [4]. Therefore, there is a need for a multipath distribution The paper is organized as follows.…”