A First-Order Model for Depolarization of Propagating Signals by Narrowband Ricean Fading Channels

We show by simulation that when the fading signals observed on orthogonally polarized diversity branches follow Ricean statistics, the distribution of polarization states on the Poincar′e sphere is well-approximated by a Fisher distribution. Further, we show that the Fisher concentration parameter is: (1) completely determined by the corresponding Ricean Kfactors and the cross-correlation coefficient between the diversity branches, both of which can be estimated from simple measurements of received power vs. time, and (2) a good indicator of the level of cross-polar discrimination (XPD) on the channel. The insights gained are potentially useful to those engaged in the development and validation of schemes that use either polarization re-use or polarized MIMO.     

Semi-deterministic channel model for multiple input multiple output systems. Part 1: Model development and validation

In this study a mathematical model, named `single interaction scattering reflecting (SISTER)`, to characterise wireless communication channel for outdoor and indoor environments is introduced which falls into semi-deterministic channel models. The aim of this study was to bridge the gap between the complicated theory of radio signal propagation and the idealised models using statistical channel properties for analysing multiple input multiple output (MIMO) systems. Therefore proposed model is developed based on the electromagnetic scattering and reflection and fundamental physics; however, it has been kept simple through appropriate assumptions. This model is validated by a three-dimensional ray-tracing tool. The numerical results obtained for different scenarios are presented and discussed in Part 2 of this paper.     

Semi-deterministic channel model for MIMO systems Part-II: results

This article presents the results of applying `single interaction scattering reflecting' (SISTER) model to different multiple-input multiple-output (MIMO) channels. The SISTER model is a semi-deterministic channel model which is described in details in Part-I of this article. MIMO performance is investigated for outdoor and indoor environments considering both line of sight (LOS) and non-line of sight (NLOS) cases. Different results are obtained by changing antenna array parameters such as spacing and number of elements and antenna half power beam width (HPBW), as well as environment parameters such as ground`s and walls` conductivity, and number and distribution of scatterers. In addition, space and angle diversity methods are compared for most of the studied cases. As the results show for most scenarios, the MIMO performance may be further improved by using multi-beams (angle diversity) rather than multi-antenna elements (space diversity).