Measurements and Channel Modelling of Microwave Line-of-Sight MIMO Links

The fading characteristics during meteorological conditions such as rain and variations of the atmospheric refractivity for Line-of-Sight (LOS) Multiple-Input-Multiple-Output (MIMO) channels are investigated. Measurements have been performed on two prototype LOS-MIMO links in Gothenburg, Sweden. It is showed that rain can be modelled as a fully correlated attenuation of the received MIMO signal. Refractive fading, caused by variations of the atmospheric refractivity, can be modelled as correlated multipath fading and especially as Rician fading. Later in the thesis, we investigated the performance and outage probability of LOS-MIMO systems compared to conventional Single-InputSingleOutput (SISO) systems in a Rician channal. Two MIMO systems are analyzed, a linear zero-forcing (ZF) system and an optimal (capacity-achieving) system using Singular Value Decomposition (SVD) of the channel. It is shown from simulation that an SVD system offers lower or equal outage probability than its SISO counterpart while the ZF system introduces a power penalty offset, given an equal probability of outage.