Measurements and models for 38-GHz point-to-multipoint radiowave propagation

This article presents results of a wide-band measurement campaign conducted at 38 GHz, The objective of the research was to determine multipath and ti me varying channel behavior of short-hop millimeter-wave point-to-multipoin t radio links during various weather events, 73 963 power delay profiles (P DP's) were captured on three links, each comparable to proposed local multi point distribution systems (LMDS) in a campus environment. Multipath was ob served in unobstructed LOS links during rain but not during clear weather. Short-term variation of the received signal over 1-2 min observation period s is described by a Rician distribution with a K factor which varies as a f unction of rain rate. Measured rain attenuation exceeds Crane Model predict ions by several decibels. A novel prediction technique is presented that applies canonical antenna pa tterns and site specific information to estimate worst case multipath chann el characteristics including relative power, time of arrival (TOA), and ang le of arrival (AOA) of each multipath component. New metrics, the excess de lay zone and relative power zone, are defined and contour plots are develop ed to determine potential reflectors from an area site map. These results a nd models provide useful guidelines for the design of millimeter-wave wirel ess communication systems.