A statistical model for the dual polarised MIMO land mobile satellite channel at S-band
Abstract
This thesis explores channel modelling approaches to the land mobile satellite (LMS)
channel in S-band, focussing on the implementation of multiple input multiple output
techniques through the use of dual polarisation. An Enhanced Statistical Model is
presented and the output of this model is analysed and compared to the two current state-of-the-art models that simulate the dual polarised LMS channel, i.e. the
statistical Liolis-CTTC model and the geometric ray-tracing QuaDRiGa model.
The enhanced model builds on the Liolis-CTTC model and presents solutions to a
number of issues that arise in the statistical modelling process. The enhancements in
the new model include imposing temporal correlation on the slow variations without
unwanted high frequency components from low-pass filtering, introducing Doppler effects including Doppler shaping of the fast variations, implementing a smooth state
transition process and also implementing an interpolation process to sample the channel at the required sub-symbol rate for transmission.
In addition to the analysis of the three models, real channel measurements of the
dual polarised LMS channel from the MIMOSA campaign are analysed. A statistical
comparison between the models and the real measurement data for simulated journeys
in a number of user environments is conducted through analysis of the timeseries, the
cumulative density function (CDF), average fading duration (AFD) and level-crossing
rate (LCR). Capacity analysis and eigenvalue analysis is also conducted and allows
for validation of the enhanced model. The comparisons with the measurement data
show good agreement between the real measurement data and the enhanced model.