Spatial correlation function and coherence time characterization of 3.5-GHz micro-cell propagation

Time selective fading investigations based on 3.5-GHz SISO narrowband envelope data are carried out in a micro-cellular propagation environment. Spatial correlation functions are calculated and compared to the theoretical Nakagami-Rice correlation function, and a good match was obtained. An alternative formulation of the autocorrelation estimator suitable not only for stationary environments is used in this article. Based on the field trial data, coherence time (T₀) statistics at 0.5-correlation level were calculated and found to be highly dependent on the receiver position. T₀ distribution functions at 0.5-correlation level showed that the coherence time stays above 1.7 ms for 90% of time when the receiver is moving at 30 km/h.