Macroscopic diversity performance measured in the 800-MHz portable radio communications environment

Analysis of 816 MHz residential propagation data is presented, demonstrating the usefulness of macroscopic selection diversity in combatting shadow fading produced by buildings and other large geographic features in the portable radio communication environment. Macroscopic diversity can reduce the link margin needed for 99% reliability by 10 dB. The analysis of these data indicates that log-normal shadow fading is partially correlated on the paths between a portable user and several surrounding ports. A two-component shadow-fading model duplicates this behavior. One log-normal term is identical for all paths from a given location and characterizes the propagation losses associated with the location. A second log-normal component is independent for each path and characterizes the remainder of the path to the port. The model fits the propagation data as well. A standard deviation of 8 dB for the path-specific term fits subsets of the available data well and is consistent with the standard deviation of shadow fading in the mobile (vehicular) communication environment.<
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