1,814 research outputs found
On Some Unifications Arising from the MIMO Rician Shadowed Model
This paper shows that the proposed Rician shadowed model for multi-antenna communications allows for the unification of a wide set of models, both for multiple-input multiple-output (MIMO) and single- input single-output (SISO) communications. The MIMO Rayleigh and MIMO Rician can be deduced from the MIMO Rician shadowed, and so their SISO counterparts. Other more general SISO models, besides the Rician shadowed, are included in the model, such as the κ-μ, and its recent generalization, the κ-μ shadowed model. Moreover, the SISO η-μ and Nakagami-q models are also included in the MIMO Rician shadowed model. The literature already presents the probability density function (pdf) of the Rician shadowed Gram channel matrix in terms of the well-known gamma- Wishart distribution. We here derive its moment generating function in a tractable form. Closed- form expressions for the cumulative distribution function and the pdf of the maximum eigenvalue are also carried out.Universidad de Málaga. Campus de Excelencia Internacional AndalucÃa Tech
Reconfigurable Antennas in mmWave MIMO Systems
The key obstacle to achieving the full potential of the millimeter wave
(mmWave) band has been the poor propagation characteristics of wireless signals
in this band. One approach to overcome this issue is to use antennas that can
support higher gains while providing beam adaptability and diversity, i.e.,
reconfigurable antennas. In this article, we present a new architecture for
mmWave multiple-input multiple-output (MIMO) communications that uses a new
class of reconfigurable antennas. More specifically, the proposed lens-based
antennas can support multiple radiation patterns while using a single radio
frequency chain. Moreover, by using a beam selection network, each antenna beam
can be steered in the desired direction. Further, using the proposed
reconfigurable antenna in a MIMO architecture, we propose a new signal
processing algorithm that uses the additional degrees of freedom provided by
the antennas to overcome propagation issues at mmWave frequencies. Our
simulation results show that the proposed reconfigurable antenna MIMO
architecture significantly enhances the performance of mmWave communication
systems
- …