Site-specific Propagation Prediction for Pcs System Design

Wireless communications has been plagued by our inability to fully understand how radio waves behave in complicated channels. In the past, anti-fading and anti-multipath techniques such as diversity and equalization have been used to combat the random small-scale fluctuations induced by radio channels, and propagation models were developed to help the communication engineer design radio links in a statistical sense, without much hope for complete understanding of the channel conditions at any particular time or location. Given the difficulty of predicting instantaneous channel conditions, a common thread in radio communication system design has histo:-: :ally been that first there must be good first-order models to successfully deploy radio system links, and then some form of diversity or equalization must be used to ensure a particular outage criterion is met during rapid changes in the channel.