Short-term fading correlation between elements of an antenna array in an indoor environment for ´MIMO´ communication systems

The short-term spatial fading correlation experienced in a channel measurement by a uniform linear array (ULA) antenna of half-wavelength element separation at 5.2 GHz in an indoor environment is studied. The focus is on the variation of correlation as the mobile unit moves along the measurement path. The measure of the severity is the magnitude of the complex correlation coefficient and the scenarios considered include, line-of-sight (LOS), and obstructed cases. It is found that significant changes in correlation levels can occur when the path alternates between non-LOS and LOS. The availability of LOS to the transmitting antenna resulted in a higher level of correlation. The effect of removing the mutual coupling between the antennas by post-processing is also considered.