Extension of Indoor SISO Propagation Models for Correlated MIMO Channels - An Exemplification Applying Saleh's Model

A novel strategy for the modeling of indoor MIMO channels based on a spatial extension of appropriate SISO channel models is presented. The approach enables a precalculation of potential MIMO spectral efficiencies within a particular environment from the SISO channel information while taking into account the correlation of the MIMO channel. The objective measure is given by the spatial probability distribution of the MIMO capacity which is to be predicted correctly. The method is exemplified by Saleh's popular SISO indoor channel model. However, the approach is not limited to this SISO model. In order to practically verify the method, firstly, the key parameters for the SISO model are derived from measured data, before the extension to the MIMO channel model is performed. Finally, the spatial cumulative distribution function, which is predicted by the model is compared to its counterpart which was derived using a fast MIMO radio channel sounder. In the measurements a strong line-of-sight (LOS) signal component was always present resulting in correlated entries within the MIMO channel matrix. For the accurate capacity modeling in such correlated channels, the characterization of the LOS signal part by a spherical wave model is a crucial prerequisite.