Frequency Dependent Indoor MIMO Channel Characterisation between 2 and 12 GHz Based on Full Spatial Correlation Matrices

The integration of wideband and multiple-input multiple-output (MIMO) radio technologies represents a powerful tool for different wireless communication standards. In the test process of these systems, new strategies for MIMO channel modelling and characterisation are necessary in order to investigate how the frequency band and the bandwidth affect the system performance. In this paper, a MIMO channel experimental characterisation based on full spatial correlation (FSC) MIMO matrices estimated from frequency domain measurements is presented. Measurements performed between 2 and 12 GHz in a stationary office scenario in both line-of-sight (LOS) and non-line-of-sight (NLOS) conditions are considered. Results show frequency dependency on the experimental MIMO channel characteristics under a high SNR regime, equal electric separation between array elements and isolation of the path loss effect. The ergodic and 1% outage capacities were reduced while the central frequency increases for different array configurations. Remarkable changes on the magnitude of the spatial correlation coefficients and on the MIMO system eigenvalues were observed for different band frequencies.