Performance evaluation of diversity antennas in multipath environments of finite richness

Abstract

The simulation tool introduced in [1] is extended further to include the emulation of non-uniform multipath environments. This extension creates a trend to generalize the definition of effective diversity gain to be applicable to nonuniform multipath environments too. We introduce the richness threshold as a further metric for diversity performance of multiport antennas. By virtue of this novel parameter, we demonstrate that beam-forming, which is ineffective in a rich isotropic multipath environment, is beneficial in non-rich isotropic multipath environments.

Spatial Diversity Performance of Multiport Antennas in the Presence of a Butler Network

“…Consequently, the random received power signals are calculated, which are accordingly used to yield different metrics such as the effective diversity gain being henceforth referred to as diversity gain. The method has been used in [17] and later generalized and further detailed in [15,Chapter 4], [5]. Therefore, we avoid detailing it again and refer the interested readers to these references.…”

“…As the number of the incident wave increases beyond this threshold, no extra diversity gain can be achieved. In our preliminary work, we referred to this novel performance metric as the richness threshold [5]. If the distribution of the incoming waves is complex Gaussian, richness threshold becomes a unique measure rendering some information about the overall performance of a multiport diversity antenna system.…”

“…In contrast, we simulate some proposed antennas in 3D multipath environments including coupling among nearby radiating elements. In addition to these, we analyze the behavior of the proposed multiport antennas in the presence and absence of a Butler network in two distinct multipath environments: (a) a rich multipath environment wherein the received signals at different ports of the antennas have converged joint probability density function and (b) a multipath environment with finite number of incident waves which is, henceforth, referred to as a non-rich multipath environment [5].…”

Coupling effects on richness threshold of multi-port antennas in multipath environments

“…But, in most practical cases, many of these performance metrics are only credible under presumption of highly rich multipath environments. By highly rich multipath, we mean an environment wherein the random received signals at different ports of the antenna present converged joint probability density functions [3]. Conversely, in actual multipath environments, the number of incoming waves is finite [2].…”

“…Under this constraint, diversity performance of a multi-port antenna can be quite different. To take into account the aforementioned issue, the notion of richness threshold has been introduced in [3]. Defined as the minimum number of independent incoming waves required to realize a converged diversity gain, richness threshold plays an important role in multipath environments of finite richness.…”