Measurement analysis of spatial and temporal correlation in wideband radio channels with adaptive antenna array

This paper investigates the spatial and temporal correlation by measurements of an 8-element adaptive antenna array. The channel measurement data is gathered at a 2.154 GHz range outdoor radio channel. The measurement analysis is divided into three different categories: investigation of spatial correlation between antenna elements at the base station (BS), spatial correlation of different mobile station (MS) locations and temporal correlation of the different multipath components. Also the differences in the correlation coefficient functions by using the complex-valued taps instead of the magnitude-valued taps are studied at the BS. The measurement analysis reveals that signals strongly correlate in the nearby BS antenna elements. However, at the different MS locations uncorrelated signals can be received when the physical separation is larger than half a wavelength. The multipath components in the impulse response profile become temporally uncorrelated after the excess delay values of 50 ns.